Bull. nat. Hist. Mus. Lond. (Zool.) 66(2): 109-146 Issued 30 November 2000

The shallow-water marine Mollusca of the -——:

THE NATURAL

Kstero Elefantes and Laguna San Rafael, | "!S'ORY “useUly

southern Chile NOV 2000

i.6

m4 x

DAVID G. REID

Department of Zoology, The Natural History Museum, London SW7 5BD, U.K. E-mail: dgr@nhm.ac.uk

CECILIA OSORIO

Departamento de Ciencias Ecolégicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425,

Casilla 653, Santiago, Chile. E-mail: cosorio@uchile.cl

SYNOPSIS. Taxonomically, the Mollusca of southern Chile are moderately well known, but the literature is scattered, there is

little information on their habitats, and distributional records are scarce for the Chilean archipelago lying between Isla Chiloé and

Tierra del Fuego. In 1998 a survey was made of the marine biodiversity of the Laguna San Rafael National Park and an area of

the Chonos Archipelago immediately to the north (approximately 46°S). The Laguna consists of a basin of low salinity, strongly

influenced by glacial meltwater, and the Estero Elefantes is a complex fjord system with both brackish and fully marine

environments, including sheltered bays and exposed coasts. Collections of molluscs were made at 26 stations, from intertidal

habitats, kelp plants and by dredging from depths of up to 15 m. A total of 62 species was recorded, consisting of 9

Polyplacophora, 33 Gastropoda and 20 Bivalvia. In order to facilitate future studies in the region, these are briefly described and

all the shelled species illustrated (12 of these photographed for the first time). Notes are given on habitats, depth and salinity, and

geographical ranges are reviewed. Biogeographically, the area lies at the poorly known southern extreme of the transitional zone

between the Magellanic and Peruvian faunal provinces. As a result, 27% of the species records are extensions to the known

ranges, representing northern limits of Magellanic forms and southern limits of Peruvian ones. Of the 62 species found, 48% could

be classed as Magellanic (found in the transitional zone and southwards) and 8% as Peruvian (found in the transitional zone and

northwards), while the remainder occurred in both provinces.

INTRODUCTION

The archipelago or fjordland of southern Chile is a remote and

relatively inaccessible area where little marine research has previ-

ously been carried out. In the heart of the fjordland (at a latitude of

46°S) lies the Laguna San Rafael National Park, a protected area of

1.7 million hectares. In recognition of its importance as a wilderness

area covering a wide range of habitat types, with no significant

human impact, the park has been declared a UNESCO Biosphere

Reserve. Knowledge of the biodiversity of the area, and in particular

that of the marine habitats, remains poor. Therefore, in 1996 a

biodiversity research programme was initiated as a collaboration

between the administrative authority of Chilean protected areas, the

Corporacion Nacional Forestal (CONAP), the youth development

charity Raleigh International, the Museo Nacional de Historia Natu-

ral in Santiago, the Natural History Museum in London and the

World Conservation Monitoring Centre in Cambridge. This report

describes the results of the initial survey in 1998 of the marine

molluscs of the Laguna San Rafael and southern Estero Elefantes

that lie within the park, and an area of the Estero Elefantes in the

vicinity of Isla Traiguén immediately to the north of the present park

boundary. A preliminary report on the general marine survey of this

area has been prepared by Paterson et al. (in press).

Dell (1971) has outlined the history of malacological investiga-

tions in southern Chile, and only a brief account will be repeated

here. Owing to its strategic importance, the Magellan Strait was the

object of several British surveys by H.M.S. ‘Beagle’ and ‘Adven-

ture’ during 1826 to 1830, from which the Mollusca were described

by King & Broderip (1832). Although this work is scarce and not

illustrated, it nevertheless contains the first descriptions of many of

the common shallow-water species of the Magellanic region. From

about 1822 to 1831 the notable collector Hugh Cuming was based in

Chile, where he amassed a great collection which was eventually

acquired by the British Museum. This material was the source of

many of the new species described by Sowerby (1833a, b, 1834,

1835, 1838, 1840) and by Reeve, later illustrated in Reeve’s

Conchologia Iconica (1843-1878). The largest single work on the

Mollusca of South America was d’Orbigny’s monumental Voyage

dans l’Amérique Méridionale (1834-1847), based on the results of

his own extensive travels in the southern part of the continent.

Malacological knowledge of Chile was further advanced by the

collections of Gay, described by Hupé (1854), and by the arrival in

Santiago in 1851 of Philippi. As a result, by the middle of the

nineteenth century the molluscan fauna of southern South America

was remarkably well known.

Towards the end of the nineteenth and in the early twentieth

century a number of important expeditions continued the biological

survey of the Magellanic region and dredging activities revealed

more of the subtidal fauna. Molluscs from the ‘Alert’ expedition

were described by E. A. Smith (1881), those from the French

Mission to Cape Horn by Mabille & Rochebrune (1889), from

Swedish and German expeditions by Strebel (1904-1907) and from

the ‘Discovery’ cruises by Powell (1951) and Dell (1964). Two later

expeditions are the source of most of the little existing knowledge of

the fauna of the fjordland between Puerto Montt and the Magellan

Strait. First was the Lund University Chile Expedition which made

extensive collections in the vicinity of Puerto Montt and Isla Chiloé

(41-43°S) during 1948-1949, and also sampled a few localities

further south in the Chonos Archipelago (44-46°S) and Magellan

Strait (52-54°S). Important taxonomic accounts of the Poly-

placophora (Leloup, 1956), Cephalopoda (Thore, 1959), Bivalvia

110

(Soot-Ryen, 1959) and Lamellariacea and Opisthobranchia (Marcus,

1959) were produced, but no report on the Gastropoda appeared

(although some of the new records were published by Brattstrom &

Johanssen, 1983). The second was the Royal Society Expedition to

Southern Chile in 1958-1959. Again collections were made around

Isla Chiloé, and also at Isla Wellington (49°S) and to the south of

Tierra del Fuego at Isla Navarino (55°S). The Mollusca from this

expedition were described by Dell (1971). Although Marincovich’s

(1973) study of the intertidal molluscs of Iquique relates to an area

in the north of Chile (20°S), it is a useful account of the more

common Peruvian species, some of which extend to the southern

part of the country; it is also unique among all previous reports in

being comprehensively illustrated. Recently, an extensive dredging

programme has been carried out in the Beagle Channel (55°S)

(Linse, 1997). A number of useful catalogues have appeared: of the

molluscs of Argentinian Patagonia (Carcelles, 1950); of the mol-

luscs of the Magellanic region (Carcelles & Williamson, 1951; and

anotable series of 14 papers by Castellanos and others, 1988-1993);

of the bivalves of Chile (Osorio & Bahamonde, 1970); of the

bivalves of the entire eastern Pacific Ocean (Bernard, 1983) and of

the Sacoglossa and Nudibranchia of Chile (Schrédl, 1996).

Later in the twentieth century the production of faunistic works

declined and emphasis shifted towards monographic revisions of

taxonomic groups at a regional or wider level. Among those that

have included Chilean species are monographs of Chiton (Bullock,

1988), other polyplacophoran families (Kaas & Van Belle, 1985—

1994), Nacellidae (Powell, 1973), Fissurella (McLean, 1984),

rissoiform gastropods (Ponder & Worsfold, 1994), Acanthina (Wu,

1985), Xymenopsis (Pastorino & Harasewych, 2000), Volutidae

(Weaver & duPont, 1970), Protobranchia (Villarroel & Stuardo,

1998), Mytilidae (Soot-Ryen, 1955), Chlamys (Waloszek, 1984)

and Teredinidae (Turner, 1966).

In conclusion, therefore, there is an impressive array of literature

available for the identification of the molluscs of southern Chile.

Nevertheless, this literature is difficult for the non-specialist to use,

for it is widely scattered and most of the potentially useful faunistic

reports and catalogues are not illustrated, or only inadequately so.

There are also deficiencies in geographical coverage, for the major-

ity of collecting effort has been expended on the Magellan Strait,

Tierra del Fuego and the Patagonian Shelf in the south, and to a

lesser extent on Isla Chiloé and the central region of Chile. Conse-

quently, geographical ranges are poorly known (Brattstrom &

Johanssen, 1983; Schrodl, 1997). Furthermore, this inadequate sam-

pling makes it difficult to evaluate cases of geographical variation as

either clines, allopatric subspecies or partially sympatric sibling

species (examples include Chiton magnificus, Nacella magellanica,

Scurria ceciliana, Acanthina monodon, Malletia magellanica,

Felaniella inconspicua and Carditella tegulata). With the exception

of commercial species, anatomical and genetic work on molluscs of

the region has only just begun. There are already several cases of

developmental and radular studies that have distinguished species

with closely similar or identical shells (e.g. Clench & Turner, 1964,

on Adelomelon and Odontocymbiola; Gallardo, 1979, on Crepidula),

and more such examples can be anticipated as detailed investiga-

tions by local workers continue. Some Magellanic molluscs show

confusing variability in shell characters, and numerous nominal

species have been described. Among the bivalves, examples include

the genera Mulinia and Zygochlamys; in the latter case availability

of an enormous series of shells has led Waloszek (1984) to

synonymize several poorly defined species in one variable taxon. In

the gastropod genera Acanthina, Trophon, Xymenopsis and

Pareuthria shell variability may be connected with local adaptation

facilitated by the nonplanktonic development that is common at high

D.G. REID AND C. OSORIO

latitudes, or perhaps by ecophenotypic effects. Almost three dec-

ades after Dell’s (1971) review of the state of systematic malacology

in Chile, it remains true that these confusing taxa are, in his words,

‘outstanding examples of groups demanding modern treatment by

workers on the spot’.

A review of ecological research on molluscs in southern Chile is

beyond our scope here. Suffice it to say that distribution and life

history of the several commercially important species have received

most attention, as reviewed by Osorio, Atria & Mann (1979).

Marine molluscs are an important resource in Chile, and intertidal

and shallow-water species are widely collected by artisanal fisher-

men (‘divers-mariscadores’ and ‘recolectores de orilla’). National

Statistics for 1997 indicate that 7554 fishermen extracted 93269

tonnes of molluscs (Servicio Nacional de Pesca, 1998). Examples of

recent field studies on commercial species include work on

Concholepas concholepas (Castilla & Duran, 1985; Moreno, Reyes

& Asuncio, 1993), Choromytilus chorus (Navarro, 1988; Moreno,

1995), Ensis macha, Tagelus dombeii and Venus antiqua (Clasing,

Brey, Stead, Navarro & Asencio, 1994; Urban, 1994, 1996; Urban &

Tesch, 1996). Some of the more common intertidal molluscs have

been mentioned in studies of zonation and community structure

(Jara & Moreno, 1984; Alvarado & Castilla, 1996), including a

series of investigations on the influence of human predation on the

organization of intertidal communities (Moreno & Jaramillo, 1983;

Duran, Moreno, Lunecke & Lepez, 1986; Castilla & Oliva, 1987). In

general, however, field research has been concentrated on the central

Chilean coast and around Isla Chiloé (Ramorino, 1968; Brattstr6m,

1990; Santelices, 1991), together with a few studies in the Magellan

Strait and Beagle Channel (Guzman, 1978; Miranda & Acufia,

1979; Ojeda & Santelices, 1984; Castilla, 1985; Benedetti-Cecchi &

Cinelli, 1997; Linse, 1997; Linse & Brandt, 1998). To our know-

ledge, there has been but one previous report on marine ecology

within the Laguna San Rafael National Park, an account of the

impoverished brackish-water ecosystem of the Laguna itself (Dav-

enport etal., 1995) that mentioned only two molluscs. The taxonomic

reports of the exploratory cruises mentioned earlier did mostly

include depth ranges and habitat notes for the species encountered.

Such, then, is the status of research on molluscs in southern Chile.

With this in mind, we have the following objectives in the present

survey. To facilitate future marine ecological work in this neglected

part of southern Chile we briefly describe the 62 species discovered

during the exploration of the Laguna San Rafael National Park and

adjacent area, and clearly illustrate the 59 species with external

shells (in 12 cases these are the first photographic illustrations of the

species). We give notes on habitats and station lists; of interest here

is the gradient of reduced salinity towards the San Rafael Glacier,

and the differential penetration of brackish water by the species. As

a guide to the scattered taxonomic literature we give abbreviated

synonymies, and point out those taxa requiring systematic revision.

The geographical range of each species is critically reviewed, based

on literature records and museum collections. Since the study area

lies within such a poorly studied region of the Chilean coast, and in

the zone of transition between Magellanic and Peruvian faunal

provinces, many of our records represent significant range exten-

sions.

THE ENVIRONMENTAL SETTING AND

MOLLUSCAN ASSOCIATIONS

The fjordland of southern Chile is formed from sunken ranges of

coastal mountains. Within this area the fjord system of the Laguna

MOLLUSCA OF SOUTHERN CHILE

San Rafael and Estero Elefantes is situated at a latitude of 46°S,

between the Chonos Archipelago and Taitao Peninsula to the west,

and the Andean Cordillera to the east. Immediately to the south east

lies the extensive San Valentin Icefield, and from this the San Rafael

Glacier descends to sea level, calving directly into the Laguna. This

is an enclosed body of water up to 15 km in diameter, cut off from the

open ocean of the Golfo San Esteban by a low-lying marshy

moraine. The only outlet from the Laguna is a narrow channel to the

north, the Rio Témpanos, that connects with the Golfo Elefantes at

the head of the fjord system. The Golfo in turn is delimited at its

northern end from the main Estero Elefantes by a series of spits and

islets. Beyond these, the main fjord varies in width from 3 to 10 km

and is fed by several river systems from the mountains to the east,

while to the north and west it eventually connects with the open sea

through a complex system of channels between the large islands of

the Chonos Archipelago. Rainfall in the region is heavy throughout

the year, with up to 4000 mm annually (Viviani, 1979; Davenport et

al., 1995), and both freshwater runoff and glacial meltwater have a

strong local influence, lowering the seawater salinity in the vicinity

of the numerous rivers and streams. Mean monthly temperature

varies between about 5 and 15°C (Viviani, 1979). The area covered

by our survey extends from the Laguna San Rafael to Isla Traiguén,

a distance of 120 km. As a result of the physical configuration of the

fjord system, three somewhat distinct regions can be distinguished:

the Laguna San Rafael, the Golfo Elefantes and the Estero Elefantes

(Figure 1). A general description of physical features and marine

zonation has been provided by Paterson et al. (in press), and here

only a short account of the main habitats and molluscan assemblages

will be given.

The Laguna San Rafael (technically an estuarine ob) is 80-250 m

deep and contains icebergs from the glacier. The shoreline is mainly of

rocks and gravel (stations 29, 30; Table 1), moderately sheltered from

wave action except in the immediate vicinity of the glacier where

waves are produced by calving icebergs. On the shallower and more

sheltered northeastern shore there is development of mudflats and

some salt marsh (station 31). The salinity is low (15—17%c) and the

water column is well mixed (Davenport et al., 1995). Diversity of

algae and invertebrates is low, and only three mollusc species were

found: Mytilus edulis chilensis on boulder shores and in the sublittoral

fringe, Malletia magellanica in soft sediment to a depth of 10 m and

Chilina patagonica on mud among saltmarsh vegetation.

The Golfo Elefantes is characterized by increasing salinity (15—

21%o at surface) and moderate wave action. The shoreline of the

investigated area (station 25) consisted of low conglomerate cliffs,

boulders and semi-sheltered coves of muddy sand. In the littoral

zone the diversity of molluscs was low and just four species were

abundant on hard substrates: Perumytilus purpuratus, Mytilus edulis

chilensis, Nacella magellanica and Siphonaria lessonii. The chiton

Plaxiphora aurata was occasional and Bankia martensi common

boring in driftwood. Valves of Mulinia edulis were found on a beach,

suggesting its presence in shallow-water sediments, and living

Aulacomya atra washed up on the shore indicated a possible subtidal

population. Dredging on a bottom of silt and cobbles revealed a

community dominated by the brachiopod Magellania venosa, and a

sparse but more diverse molluscan fauna of 10 species, including the

predatory whelks Trophon plicatus, Xymenopsis muriciformis,

Pareuthria powelli, and occasional examples of Leptochiton medinae,

Iothia coppingeri, Margarella violacea, Eumetula pulla, Lamellaria

ampla, Malletia magellanica, and Venus antiqua. In the estuary of

the Rio Gualas (station 26) a heavily silted boulder shore was

encrusted with the barnacle Elminius and the green alga Entero-

morpha, and the only living molluscs were Mytilus edulis chilensis,

Perumytilus purpuratus and Plaxiphora aurata.

111

Along the Estero Elefantes (including the southern shores of Isla

Traiguén at its northern end) there were a variety of shore types and

a wide range of wave-exposures. Surface salinity readings ranged

between 5—15%c in estuaries, 15—22%c in the southeastern corner of

the Estero, and elsewhere approached fully marine conditions (27—

33%o). The depth of the Estero varies between 185 and 440 m (with

a sill of 150 m at its northern end), with a halocline at 7-8 m and

deep salinity of 32%o (Pickard, 1971). Only here were strongly

wave-exposed (stations 16, 17) and moderately wave-exposed

(stations 5, 12, 13, 14) rocky shores encountered. A characteristic

zonation was developed on such shores which, from the perspective

of molluscan distributions, can be summarized as follows. At the

upper limit of the eulittoral zone the only mollusc was Nodilittorina

araucana, abundant on rocks partly encrusted with the red alga

Hildenbrandia. Below, in the upper mid eulittoral, a band of small

barnacles (Notochthamalus) was present, sometimes with the algae

Tridaea and Porphyra, and associated molluscs were Nodilittorina

araucana, Siphonaria lessonii and, in the interstices of the barna-

cles, the minute bivalve Lasaea miliaris. The mid and lower

eulittoral was generally dominated by dense beds of Mytilus edulis

chilensis, sometimes together with Perumytilus purpuratus in the

upper part (especially in more sheltered areas or where freshwater

runoff occurred), and (only in the most exposed sites, stations 13,

17) replaced by Aulacomya atra in the lowest eulittoral and

sublittoral fringe. Other characteristic molluscs of the Mytilus belt

included Scurria parasitica attached to the mussels, the predatory

Acanthina monodon and the herbivores Nacella magellanica,

Tegula atra, Fissurella picta and Chiton granosus. On some shores

it appeared that density of these grazers was sufficient to produce a

narrow bare zone devoid of macroalgal cover in the lowest

eulittoral. On exposed shores the rock surfaces in the sublittoral

fringe were encrusted by calcareous red algae, sea urchins were

abundant, and at the top of this zone clumps of the large barnacle

Austromegabalanus were frequent. Mollusca of the sublittoral

fringe included Tegula atra, Argobuccinum pustulosum ranelli-

forme and, in one strongly exposed site (station 16), Concholepas

concholepas. Sheltered microhabitats on these exposed shores,

such as large rock pools and among boulders, harboured a more

diverse range of molluscs including the gastropods Crepidula

dilatata, Trochita trochiformis, Trophon plicatus, Pareuthria

fuscata, P. powelli, Nassarius gayii and Tritonia challengeriana,

and the chitons Chaetopleura peruviana, Ischnochiton stramineus,

Chiton magnificus, Tonicia atrata and T. chilensis.

In bays and inlets of the Estero Elefantes, relatively sheltered

from wave action, both bedrock and boulder shores were dominated

by algae (stations 1, 7, 8, 20). In the upper eulittoral zone filamentous

algae such as the red Bostrychia and green Enteromorpha were

common, together with barnacles, but replaced in the mid and low

eulittoral by large fleshy algae among which the red Mazzaella and

Nothogenia were most abundant. On sheltered shores of this type the

limpets Nacella magellanica, Scurria ceciliana and Siphonaria

lessonii were common on rock surfaces on the upper shore, and

Diloma nigerrima beneath boulders. Lower on these shores a di-

verse assemblage of molluscs occurred among boulders, including

Chiton magnificus, Tonicia atrata, Plaxiphora aurata, Fissurella

nigra, Tegula atra and Acanthina monodon. In areas of low salinity

diversity was reduced (stations 6, 11,21, 22), and on such shores the

molluscan fauna resembled that of corresponding areas of the Golfo

Elefantes. As in the Laguna San Rafael, the only molluscs on

muddy, estuarine shores of lowest salinity (5%o, station 28) were

Mytilus edulis chilensis and Chilina patagonica. Sedimentary shores

with normal salinity were scarce in the Estero Elefantes; only one

sheltered sandy bay was examined (station 1). Here the bivalves

112 D.G. REID AND C. OSORIO

Isla iin

Traiguen

(Pee

study area

patsy Tierra

de] Fuego

j “Yj

2p)

PROSE (i Sepa eet ere

SHEER eae

= |Golfo San Esteban?

V/A \ce sheet

Water Kilometres

[__] Laguna San Rafael National Park boundary 0 30

w E

@ Sampling station

Fig. 1 Survey stations in the Laguna San Rafael, Golfo Elefantes and Estero Elefantes. See Table 1 for coordinates, salinity and temperature data.

MOLLUSCA OF SOUTHERN CHILE

Venus antiqua, Tagelus dombeii and Ensis macha were recorded. On

muddy shores of intermediate salinity the bivalve Mulinia edulis

was frequent (station 20).

Dredging to a depth of 15 m in the Estero Elefantes (stations 1, 9,

14, 22) yielded the most diverse molluscan assemblage encountered

during the entire survey, although numbers of individuals were

always low. The 25 species found were Chiton magnificus, Tonicia

chilensis, Ischnochiton pusio, Leptochiton medinae, Puncturella

conica, Iothia coppingeri, Margarella violacea, Homalopoma

cunninghami, Crepidula dilatata, Xymenopsis muriciformis, X. sub-

nodosus, Pareuthria powelli, Glypteuthria meridionalis, Nassarius

gayii, Adelomelon ancilla, Nucula pisum, Zygochlamys patagonica,

Felaniella inconspicua, Carditella tegulata, Carditopsis flabellum,

Cumingia mutica, Venus antiqua, Retrotapes exalbidus, Tawera

gayi and Hiatella solida.

Much of the shore of the Estero Elefantes was fringed by exten-

sive beds of the giant kelp, Macrocystis pyrifera (sampled at stations

1, 7, 14, 22), growing from depths of about 10 m. In fully marine

situations the laminae of the kelp supported occasional animals of

Nacella mytilina and Flabellina falklandica, while in the holdfasts

were found Fissurella oriens and Aulacomya atra. In conditions of

lower salinity in the southern part of the Estero (station 22) the

species Leptochiton medinae, Plaxiphora aurata, Aulacomya atra

and Hiatella solida were present in the holdfasts.

MATERIAL AND METHODS

The majority of the material was collected during intertidal surveys.

Sampling was by general collecting and by quantitative transect

methods (the results of which will be reported elsewhere). A limited

amount of dredging was carried out in depths of up to 15 m, using a

small handmade apparatus (aperture 70 by 15 cm, with sacking

attached) dragged behind an inflatable boat. Plants of the giant kelp

Macrocystis were pulled up from depths of up to 10 m, and both

holdfasts and laminae examined for molluscs. Searches for

micromolluscs were made by washing dredged and hand-collected

samples of algae in freshwater, and also by close examination of

dredged sediments. Strandlines were searched for dead shells but,

unless otherwise noted, all records refer to living specimens. Collec-

tions and observations were made at a total of 26 stations (Table 1,

Figure 1). Surface salinity and temperature were noted. Material

was preserved in 10% seawater formalin and later transferred to

80% ethanol for storage. Duplicate collections are deposited in both

the Natural History Museum, London (NHM) and the Museo

Nacional de Historia Natural, Santiago (MNHNS). All figured

material is in the NHM; registered specimens carry the prefix

“‘BMNHW’.

In the Systematic Descriptions an abbreviated synonymy is given

for each species. This includes the reference to the original descrip-

tion, one or more references to the most recent taxonomic accounts

that can be consulted for complete synonymies, and significant recent

systematic works. References to the key works on the molluscs of the

region (Leloup, 1956; Soot-Ryen, 1959; Osorio & Bahamonde,

1970; Dell, 1971; Marincovich, 1973) are provided for all species.

Where previous authors have used names other than the ones we

consider to be valid, these are usually synonyms; cases of misidenti-

fication are indicated by ‘not’ followed by the original authority of

the name. The descriptions and dimensions of shells are based on the

present material, with additions from other sources as noted. Dimen-

sions are the greatest linear dimension of the shell, unless otherwise

indicated. All figured specimens are from this survey, except for three

113

species in which the material was too fragmentary, in which case

specimens from the collection of the NHM have been substituted, as

noted. The designation of zones on the shore follows that of Lewis

(1964). Records of geographical distribution refer only to the Chilean

coast, as far south as Cape Horn, including the Magellan Strait, Tierra

del Fuego and the Beagle Channel.

SYSTEMATIC DESCRIPTIONS

Class Polyplacophora

Family LEPTOCHITONIDAE

Leptochiton (Leptochiton) medinae (Plate, 1899)

(Figure 6A, C)

Lepidopleurus medinae Plate, 1899: 82-89, pl. 5, figs 204-206.

Leloup, 1956: 13-15, fig. 2.

Leptochiton medinae — Kaas & Van Belle, 1998: 122.

Leptochiton (Leptochiton) medinae — Kass & Van Belle, 1985: 80—

83, fig. 35, map 37 (synonymy).

DESCRIPTION. Valve area to 10.0 by 6.0 mm, maximum width of

girdle 1.1 mm; valves sculptured with numerous fine rows of small

granules, arranged longitudinally on central areas, radially on lateral

triangles and terminal valves; shell colour cream, often stained with

black deposits; girdle fawn, covered with minute, longitudinally

grooved, conical spicules (Fig. 6C); gills restricted to posterior part

of pallial groove (merobranchial).

HABITAT. Commonly dredged from 3-15 m; in Macrocystis

holdfasts; on cobbles encrusted with calcareous red algae; on peb-

bles and shells lying on silt; at salinities down to 15—22%o. This has

been recorded as a common sublittoral species in 15—30 m (Dell,

1971; Kaas & Van Belle, 1985), and to a depth of 250-300 m

(Leloup, 1956); Dell (1971) also noted one collection from the

intertidal Jridaea zone.

RECORDS. Stations 7, 22, 25. Elsewhere Puerto Montt to Tierra del

Fuego and Magellan Strait (Leloup, 1956; Kaas & Van Belle, 1985).

Range: 40-56°S.

REMARKS. This species should not be confused with the similarly

small, cream species Ischnochiton stramineus, which possesses

slitted insertion plates, quincuncial (not longitudinal) granular sculp-

ture and holobranchial gills.

Family ISCHNOCHITONIDAE

Chaetopleura (Chaetopleura) peruviana (Lamarck, 1819)

(Figure 2A)

Chiton peruvianus Lamarck, 1819: part 1: 321.

Chaetopleura peruviana — Leloup, 1956: 37-40, figs 18-20. Dall,

1971: 218. Marincovich, 1973: 43-44, fig. 101. Ferreira, 1983:

220-221. Kaas & Van Belle, 1998: 142-143.

Chaetopleura (Chaetopleura) peruviana — Kaas & Van Belle, 1987:

62-64, fig 27, map 11 (synonymy).

DESCRIPTION. Valve area to 49 by 22 mm, maximum width of

girdle 11 mm; valves relatively flattened; valves sculptured with

radiating rows of fine pustules; shell colour marbled olive brown,

D.G. REID AND C. OSORIO

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MOLLUSCA OF SOUTHERN CHILE

with radiating flecks of black and turquoise; girdle profusely covered

with long (to 7 mm), brown, corneous hairs, with dense minute

spicules beneath.

HABITAT. Underrocks in lowest eulittoral, on moderately exposed

shores. It has been recorded from throughout the tidal zone and to a

depth of 40 m (Leloup, 1956; Kaas & Van Belle, 1987). It appears to

be scarce on the shores of central and northern Chile (Guiler, 1959a;

Marincovich, 1973; Otaiza & Santelices, 1985).

RECORDS. Stations 12, 17. Kaas & Van Belle (1987) gave a range

from Cape San Lorenzo (Ecuador) to the Chonos Archipelago, and

our records are therefore at the southern extreme. However, Leloup

(1956) mentioned occurrence in the Magellan Strait (53°S), but

without details. Range: 146°S.

REMARKS. Both Kaas & Van Belle (1987) and Ferreira (1983)

mentioned that the girdle hairs characteristically protrude from the

sutures between the valves, but this was not the case in our material.

Dell (1971) also noted the lack of sutural hairs in some specimens

from Punta Pulga (42°S), and suggested that this might be due to

exposure.

Family ISCHNOCHITONIDAE

Ischnochiton (Ischnochiton) stramineus (Sowerby, in

Broderip & Sowerby, 1832)

(Figure 6B, D)

Chiton stramineus Sowerby, in Broderip & Sowerby, 1832: 104.

Ischnochiton (Ischnochiton) stramineus — Kaas & Van Belle, 1990:

173-176, fig. 78, map 38 (synonymy).

Ischnochiton stramineus — Kaas & Van Belle, 1998: 178.

Ischnochiton imitator E.A. Smith, 1881 —Leloup, 1956: 42-43, fig.

22.

DESCRIPTION. Valve area to 12.0 by 5.6 mm, maximum width of

girdle 1.0 mm; valves rather flattened; lateral triangles not raised or

differentiated; sculpture of fine, quincuncially arranged granules;

shell colour cream to fawn, sometimes stained with black deposits;

girdle cream to fawn, densely covered with short, imbricating

scales, each with about 6 ribs, converging towards recurved top of

scale (Fig. 6D); gills throughout pallial groove (holobranchial).

HABITAT. Understones and cobbles resting on silt, inlarge sheltered

rock pool, 0.3—0.5 m below low water of spring tide. Leloup (1956)

recorded it throughout the intertidal zone and to a depth of 22 m.

RECORDS. Station 14. Elsewhere from Islay (Peru) to Tierra del

Fuego and Magellan Strait (Kaas & Van Belle, 1990). Range: 17—

54°S.

REMARKS. Compare with Leptochiton medinae.

Ischnochiton (Haploplax) pusio (Sowerby, in Broderip &

Sowerby, 1832)

(Figures 2D, 6E)

Chiton pusio Sowerby, in Broderip & Sowerby, 1832: 105.

Ischnochiton pusio — Leloup, 1956: 44-45, fig. 23.

Ischnochiton (Haploplax) pusio — Kaas & Van Belle, 1994: 67-69,

fig. 27, map 18 (synonymy). Kaas & Van Belle, 1998: 153-154.

DESCRIPTION. Valve area to 15.7 by 8.4 mm, maximum width of

girdle 1.7 mm; valves smooth, very fine quincuncial granulation

visible at high magnification; shell colour brown to blackish brown,

115

usually with radiating flecks of white or turquoise; girdle rather wide,

brown to black, often banded, covered with relatively large, stout,

smooth, glossy, imbricating scales with square base, scales becoming

smaller towards inner and outer margins of girdle (Fig. 6E).

HABITAT. Under stones on gravel in shallow tidal channel, just

sublittoral; 10-15 m depth in sheltered bay, on substrate of cobbles

encrusted with calcareous red algae. This species has been reported

to be common intertidally, and to a depth of 90 m (Leloup, 1956;

Dell, 1971; Brattstroém, 1990; Kaas & Van Belle, 1994).

RECORDS. Stations 7, 15. Elsewhere Tumbes (Peru) to Tierra del

Fuego (Kaas & Van Belle, 1994). Range: 12—-54°S.

REMARKS. This is superficially similar to small specimens of

Chiton magnificus bowenii, but in that species the valves are glossy,

the girdle shows a definite inner zone of smaller scales and the scales

do not become smaller at the outer margin.

Family MOPALITDAE

Plaxiphora (Plaxiphora) aurata (Spalowsky, 1795)

(Figure 2B)

Chiton auratus Spalowsky, 1795: 88, pl. 13, figs 6a, b.

Plaxiphora aurata — Leloup, 1956: 25-26. Kaas & Van Belle, 1998:

26.

Plaxiphora (Plaxiphora) aurata — Kaas & Van Belle, 1994: 266—

269, fig. 108, maps 5, 28, 41 (synonymy).

Plaxiphora carmichaelis (Gray, 1828) — Ferreira, 1982: 43-45, figs

1-8 (synonymy).

DESCRIPTION. Valve area to 75 by 30 mm, maximum width of

girdle 16 mm; valves frequently eroded; jugal and pleural areas

smooth; lateral triangles defined by two nodulose radiating ribs, one

diagonal and one posterior; shell colour purple black with radiating

lines and stripes of pink or turquoise; girdle wide, fleshy, brown,

with minute spicules and sparse tufts of long (to 8 mm) corneous

hairs, frequently fouled with algae.

HABITAT. On and under rocks in low eulittoral, on sheltered and

sometimes muddy shores; in Macrocystis holdfasts, 3-5 m depth;

tolerant of reduced salinity (range 15—31%c). Leloup (1956) recorded

this species from throughout the intertidal zone, Brattstr6m (1990)

in its lowest part and Dell (1971) noted it also to a depth of 12 m. At

an intertidal estuarine site in Argentina it was reported to occur only

on shaded vertical rock walls, reaching densities of 7-12 per m?

(Lopez-Gappa & Tablado, 1997); in contrast, it was generally scarce

in the present study area.

RECORDS. Stations 1, 7, 14, 20, 22, 25, 26. Elsewhere Valparaiso

to Tierra del Fuego and Magellan Strait (Leloup, 1956; Dell, 1971;

Kaas & Van Belle, 1994), and outside the Chilean region on the

subantarctic islands and South Island, New Zealand (Kaas & Van

Belle, 1994). Range: 31-54°S.

REMARKS. This and Leptochiton medinae were the only chitons to

be found in the areas of significantly reduced salinity in the Golfo

Elefantes.

Family CHITONIDAE

Chiton (Amaurochiton) magnificus bowenii King &

Broderip, 1832

(Figures 2C, 6F)

116

Chiton bowenii King & Broderip, 1832: 338-339. Kaas & Van

Belle, 1998: 34.

Chiton (Amaurochiton) magnificus bowenii — Bullock, 1988:165—

166, figs 55, 56, 71, 76 (synonymy).

Chiton latus Sowerby, 1825 — Leloup, 1956: 50-54, figs 26, 27

(includes nominate subspecies).

DESCRIPTION. Valve areato46 by 24mm, maximum width of girdle

5 mm (total length up to 86 mm, Bullock, 1988); valves flattened to

carinate, glossy; jugal and pleural areas smooth; lateral triangles, head

and tail valves with indistinct radiating ribs; shell colour entirely

black, dark red, orange-pink or blue-grey, often with strong pattern of

longitudinal streaks on central region and radial streaks on lateral

triangles; girdle black, red or brown, with large, glossy, imbricating

scales, the innermost one third of the width of the girdle with slightly

smaller and narrower scales than the rest (Fig. 6F).

HABITAT. Common under rocks in lower eulittoral; small juveniles

dredged on cobbles at 10-15 m depth; moderately sheltered to

exposed coasts. Leloup (1956; as C. /atus) recorded the species both

intertidally and to 2-5 m depth, and Dell (1971; as C. latus)

mentioned a maximum depth of 13 m. In central Chile the typical

subspecies inhabits pools and boulder fields from high to low tide, is

larger and more common in exposed localities, but absent from rock

walls (Otaiza & Santelices, 1985; as C. latus).

RECORDS. Stations 1, 5, 7, 12, 14, 15, 17. Elsewhere I. Chiloé,

Magellan Str. and Tierra del Fuego (43—53°S); typical subspecies I.

San Lorenzo (Peru) to I. Chiloé (Bullock, 1988) (12-43°S). Total

range of species: 12—53°S.

REMARKS. Bullock (1988) distinguished C. m. bowenii from the

typical northern subspecies by its smooth sculpture, more carinate

valves, more elongate outline, brighter coloration and smaller girdle

scales. He noted the ‘nearly complete geographical isolation of the

two’, although this is probably a sampling artefact. In Isla Chiloé he

reported that both types could be found, together with intermediates,

and this appears to question the validity of the subspecific distinc-

tion. The present material shares the smooth sculpture, small scales

and frequently bright coloration of the southern form, but the valve

profile and outline are more variable. Additional material is required

to determine whether the subspecies are indeed distinct entities, or if

there is a latitudinal cline. The synonymy of the nominate subspe-

cies 1s complex, and includes C. striatus Barnes, 1824, C. latus

Sowerby, 1825, C. olivaceus Frembly, 1827 and C. subfuscus

Sowerby, 1832 (see Bullock, 1988). Small specimens could be

confused with [schnochiton pusio.

Chiton (Chondroplax) granosus Frembly, 1827

(Figure 2J)

Chiton granosus Frembly, 1827: 200-201. Leloup, 1956: 48-50,

figs 24, 25. Marincovich, 1973: 43, fig. 98. Osorio, Atria & Mann,

1979: 13, fig. 5. Kaas & Van Belle, 1998: 84.

Chiton (Chondroplax) granosus — Bullock, 1988: 185-187, figs 96,

97, 103, 140, 141, 143, 144.

DESCRIPTION. Valve area to 44 by 25 mm, maximum width of

girdle 7 mm (total length up to 80 mm, Osorio et al., 1979); central

D.G. REID AND C. OSORIO

area with longitudinal striations; lateral triangles, head and tail

valves with radiating rows of coarse nodules; valves usually eroded

so that sculpture is not visible; shell colour dark brown to black, with

broad longitudinal pale stripe on either side of jugal tract, striking

even in eroded specimens; girdle with coarse black scales.

HABITAT. In wave-surge gullies and crevices, and on cliffs, in

lower eulittoral, on exposed shores. This species is abundant in

southern, central and northern Chile, mainly on exposed cliffs in the

mid to low intertidal zone (Jara & Moreno, 1984; Otaiza & Santelices,

1985; Brattstr6m, 1990), although it has also been reported from the

undersides of rocks (Leloup, 1956; Marincovich, 1973) and at the

high tide level (Frembly, 1827; Leloup, 1956; Brattstr6m, 1990).

RECORDS. Stations 12, 13, 17. This extends the known range of

Tumbes (Peru) to I. Chiloé (Bullock, 1988). Range: 12-46°S.

REMARKS. This species was found infrequently in the Estero

Elefantes, and then only on the most wave-exposed of the sites

visited. Moreno & Jaramillo (1983) reported that the main food of C.

granosus is barnacle larvae.

Tonicia atrata (Sowerby, 1840)

(Figure 2K)

Chiton atratus Sowerby, 1840: 294.

Tonicia atrata—Leloup, 1956: 59-67, figs 31-35 (synonymy). Kaas

& Van Belle, 1998: 25 (synonymy).

DESCRIPTION. Valve area to 85 by 30 mm, maximum width of

girdle 13 mm; jugal area with deep longitudinal striae; lateral

triangles not distinct; entire surface with fine, regular granulation

(not evident in large, eroded specimens); mucro of tail valve almost

central, post-mucronal slope convex; shell colour purplish black,

beaks often pale pink, some specimens with fine concentric lines

and irregular radial rays; girdle macroscopically smooth, with mi-

croscopic spicules, flesh pink.

HABITAT. Under stones and in pools, in lower eulittoral, on shel-

tered and moderately sheltered shores. Leloup (1956) and Brattstr6m

(1990) also recorded this species from the mid and low eulittoral,

and Dell (1971) down to a depth of 10 m.

RECORDS. Stations 1,5, 7,12, 14, 15, 20. Elsewhere Puerto Montt

to Tierra del Fuego (Leloup, 1956; Dell, 1971). Range: 40-54°S.

REMARKS. Leloup (1956) described the variation in valve form

and sculpture in this species; the present specimens correspond with

his figures of the synonymous T. fastigiata (Sowerby, 1843).

Tonicia chilensis (Frembly, 1827)

(Figure 2E)

Chiton chilensis Frembly, 1827: 204—205.

Tonicia chilensis — Kaas & Van Belle, 1998: 45 (synonymy).

Tonicia elegans (Frembly, 1827) —Leloup, 1956: 69-77, figs 38-46.

DESCRIPTION. Valve area to 37 by 15 mm, maximum width of

girdle 6 mm (total length up to 70 mm, Kaas & Van Belle, unpubl.);

jugal area with a few longitudinal striae, elsewhere almost smooth;

Fig. 2 A. Chaetopleura (Chaetopleura) peruviana (44 mm). B. Plaxiphora (Plaxiphora) aurata (42 mm). C. Chiton (Amaurochiton) magnificus bowenii

(40 mm). D. Ischnochiton (Haploplax) pusio (14 mm). E. Tonicia chilensis (20 mm). F, G. Scurria parasitica (15 mm). H, I. Scurria ceciliana (19 mm).

J. Chiton (Chondroplax) granosus (43 mm). K. Tonicia atrata (36 mm). L, M. Nacella (Patinigera) magellanica (typical form; 40 mm). N, O. Nacella

(Patinigera) magellanica (form venosa; 37 mm). P, Q. Nacella (Nacella) mytilina (32 mm). (All specimens from study area; NHM collection).

MOLLUSCA OF SOUTHERN CHILE

rae =

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118

lateral triangles often indistinct, but sometimes marked by a raised

and nodulose diagonal line, and lateral triangles sometimes bearing

small radial pustules; mucro of tail valve near anterior margin, post-

mucronal slope concave; shell colour variable, pale pink, orange,

pale green or turquoise, with fine red or purple longitudinal and

radial lines, or finely marbled pattern; girdle macroscopically smooth,

flesh pink.

HABITAT. Under stones in calcareous red algal zone of sublittoral

fringe in large, sheltered, rock pool; dredged from 10-15 m in

sheltered bay, on substrate of cobbles encrusted with calcareous red

algae. At intertidal sites in central Chile this species was also mainly

found submerged in pools (Otaiza & Santelices, 1985). Leloup

(1956) recorded it from intertidal habitats both sheltered and ex-

posed, and to a depth of 13 m.

RECORDS. Stations 7, 12. Elsewhere Tumbes (Peru) to Tierra del

Fuego (Leloup, 1956; Dell, 1971). Range: 12-54°S.

REMARKS. Both colour and sculpture of this species are highly

variable, resulting in a complex synonymy. Of the forms differenti-

ated by Leloup (1956), the present specimens correspond with f.

lineolata (Frembly, 1827), by virtue of their striking colour pattern

and mainly smooth valves, although the sculpture sometimes ap-

proaches f. grayii Sowerby, 1832.

Class Gastropoda

Family NACELLIDAE

Nacella (Nacella) mytilina (Helbling, 1779)

(Figure 2P, Q)

Patella mytilina Helbling, 1779: 104-106, pl. 1, figs 5, 6.

Nacella mytilina — Dell, 1971: 201—202 (synonymy). Castellanos &

Landoni, 1988: 27, pl. 4, figs 9, 10.

Nacella (Nacella) mytilina — Powell, 1973: 192, pl. 73, fig. 9, pls

173, 174 (synonymy). Ubaldi, 1985: 11-12, 17-18, figs 1-4.

DESCRIPTION. Shell to 32 by 24 mm, height 13 mm; shell thin,

translucent; apex one third from anterior edge; surface almost

smooth, but with faint radial riblets; horn colour, with radiating

white streaks; interior silvery iridescent.

HABITAT. On fronds of Macrocystis growing from depth of 10-15

m near shore; rare, only 3 specimens found despite examination of

many plants. It is acommon member of the epibiotic community on

Macrocystis further south in the Magellanic region (Castilla, 1985).

RECORDS. Stations 1, 14. Elsewhere I. Wellington, Magellan Strait

and Tierra del Fuego (Dell, 1971; Powell, 1973). The present

records are the northernmost. Range: 46—-55°S.

REMARKS. The shell of this species is highly variable, ranging

from semitransparent to moderately solid, and from smooth to

ribbed. The position of the apex is also variable; in typical speci-

mens (Powell, 1973: pl. 173, figs 1, 2) it is at the anterior end,

whereas in the present material it is at about one third of the shell

length from the anterior margin. It is notable that the Nacellidae are

presently accorded full familial status in the superfamily Patelloidea

(Sasaki, 1998: 208-209).

Nacella (Patinigera) magellanica (Gmelin, 1791)

(Figure 2L—O)

Patella magellanica Gmelin, 1791: 3703.

Patinigera magellanica — Dell, 1971: 204. Osorio, Atria & Mann,

D.G. REID AND C. OSORIO

1979: 14-15, fig. 8. Castellanos & Landoni, 1988: 2, pl. 3, figs 1—

Nacella (Patinigera) magellanica magellanica— Powell, 1973: 198,

pl. 73, figs 14, 15, pl. 178, figs 1, 2 (synonymy).

Patella venosa Reeve, 1854: sp. 18, pl. 10, figs 18 a—c.

Nacella (Patinigera) magellanica venosa — Powell, 1973: 198-199,

pl. 180.

DESCRIPTION. Shell to 71 by 63 mm, height 37 mm; shape vari-

able, from smooth, low-conical (height/length 0.32), round (width/

length 0.98) (form venosa, Fig. 2N, O) to radially ribbed, high-

conical (height/length 0.77), oval (width/length 0.87) (typical

magellanica, Fig. 2L, M); external colour also variable, typically

grey with dark brown radial stripes, but form venosa may in addition

be black, or cream with sparse streaks or chevrons; interior silvery

iridescent with exterior pattern showing through, spatula always

dark coppery iridescent.

HABITAT. This is an abundant species in a wide range of intertidal

rocky habitats, on exposed and moderately sheltered shores, on cliffs

and stones, from the lower barnacle zone, through the Mytilus zone, to

the low water mark. The species does not occur subtidally. On

moderately exposed vertical rock faces it is most common in a super-

ficially bare zone between the Mytilus zone above, and the calcareous

red algal zone below; in this intermediate region other herbivorous

molluscs are also common (Chiton granosus, Tegula atra, Fissurella

picta), and grazing pressure may maintain the bare rock surface.

Nacella magellanica was found at stations with salinity down to 15—

20%c. Larger specimens were found on open rock surfaces, smaller

animals beneath stones and in crevices. After 2—3 days of diurnal low

tides and clear sunny weather, animals towards the upper limit of

distribution were observed (2—3 Feb. 1998) to suffer heat coma,

dropping off the rock and dying. The distribution and density of this

species have been studied in the Magellan Strait (Guzman, 1978).

RECORDS. Stations 1,5,6,7,8, 13, 14,17,20,21,22,25.Else-where

I. Chiloé to Tierra del Fuego and Magellan Strait (Powell, 1973; Dell,

1971). The northern limit of this species is uncertain. Brattstrom &

Johanssen (1983) mention ‘Patinigera deaurata (Gmelin, 1791)

from six locations between Laguna San Rafael and Seno Reloncavi

(41°29'33"S), and mention P. magellanica from Valparaiso to the

Magellan Strait. Brattstr6m (1990) recorded N. magellanica com-

monly in Seno Reloncavi and listed a single occurrence of N. aenea

Martyn, 1784 (an invalid name for NV. deaurata). N. Nacella deaurata

is a species recognized by Powell (1973), who gave its range as the

Magellan Strait, Tierra del Fuego and the Falkland Is.; in the Beagle

Channel this species is common intertidally, together with N.

magellanica (DGR, pets. obs.), but it was not seen in our study area.

It seems likely that the records by Brattstr6ém & Johanssen (1983) of

deaurata from the Chilean archipelago arose from misidentification

of the ribbed form of N. magellanica, and accordingly we assign their

record from Seno Reloncavi to that species. The source of their record

of N. magellanica from Valparaiso is unknown, and we consider this

unreliable. Range: 41—55°S.

REMARKS. The systematics of the genus Nacella are still some-

what confused. In the most recent monograph, Powell (1973)

recognized the smoother, more round and more brightly coloured

examples from Isla Chiloé as the geographical subspecies N. m.

venosa, contrasting these with the more strongly ribbed, taller, more

oval shells of the typical forms from the southern part of the range.

In the present study the majority of specimens conformed to the

northern subspecies (Fig. 2N, O), but at station 25 in the lower

salinity (and perhaps colder) environment of the Golfo Elefantes,

the shells were mainly of the typical form (Fig. 2L, M). Inter-

MOLLUSCA OF SOUTHERN CHILE

mediates appear to connect these two forms and therefore we have

not retained the subspecific distinction. Nacella deaurata (Gmelin,

1791) was recorded, probably erroneously, from “Laguna San Rafael’

by Brattstr6m & Johanssen (1983; see above); this southern species

is a more elongate oval shape, with nodular radial ribs. Nacella

magellanica was reportedly one of the principal food species of the

Fuegian Indians (Osorio et al., 1979), but was not found in the

middens on Isla Traiguén.

Family LEPETIDAE

Tothia coppingeri (Smith, 1881)

(Figure 7A)

Tectura (Pilidium) coppingeri E.A. Smith, 1881: 35, pl. 4, figs 12,

12a.

Lepeta coppingeri — Castellanos & Landoni, 1988: 32, pl. 1, fig. 6,

pl. 3, fig. 9. Linse, 1997: 27.

Tothia coppingeri — Moskalev, 1977: 62-64, figs 5, 6. Dell, 1990:

105-106, figs 185, 186 (synonymy).

DESCRIPTION. Shell to 4.2 by 3.1 mm; delicate, translucent, apex

close to anterior end; sculptured by numerous fine, scaly, radial

riblets, but sculpture sometimes obsolete; colour usually white,

sometimes orange brown, or dark brown with white rays.

HABITAT. 10—15 m depth, on substrates of cobbles encrusted with

calcareous red algae, and of cobbles and shell debris on silt. It has

been recorded from depths of 5—1108 m (Dell, 1990; Linse, 1997).

RECORDS. Stations 7, 14, 25. Elsewhere Tierra del Fuego and

Magellan Strait, and more widely in Falkland Is and circum-Antarc-

tic (Dell, 1990). According to Dell (1990) the northern limits are not

well defined, so that our records may be the northernmost for this

species. Range: 46-78°S.

Family LOTTIIDAE

Scurria ceciliana (d’ Orbigny, 1841)

(Figure 2H, I)

Patella ceciliana d’ Orbigny, 1841: 482, pl. 81, figs 4-6.

Patelloida ceciliana — Dell, 1971: 199-200 (synonymy).

Collisella ceciliana — Marincovich, 1973: 19-20, fig. 33 (syn-

onymy). Castellanos & Landoni, 1988: 2, pl. 3, figs 10, 11, pl. 4,

fig. 2.

Scurria ceciliana — Espoz, Guzman & Castilla, 1995: 191-197, fig.

3d.

DESCRIPTION. Shell to 20 by 18 mm, height 7 mm; low-conical,

apex at one third of shell length from anterior margin; sculptured by

12—15 rounded ribs that crenulate the margin; colour white, with fine

black or brown tessellation between ribs, merging into radial lines at

margin; interior white or greenish, exterior pattern shows through at

margin, spatula irregular, dark brown or of several axial brown

streaks.

HABITAT. Onsurface of rocks with green algae in barnacle zone, in

upper eulittoral on moderately sheltered shores. Dell (1971) and

Brattstr6m (1990) recorded this species mainly from the mid and

upper littoral, but also lower on the shore. In northern Chile,

Marincovich (1973) found it in the middle and lower intertidal.

RECORDS. Stations 1, 8. Elsewhere Pucusana (Peru) to Tierra del

Fuego and Magellan Strait (Dell, 1971; Marincovich, 1973). Owing

119

to taxonomic confusion in this group (see below), the geographical

distribution is uncertain. Provisional range: 12—54°S.

REMARKS. According to Lindberg (1988), the lottiid limpets of

Chile are all assigned to the genus Scurria. These comprise a poorly

known complex of species, much in need of critical revision (contrast

the treatments by Dell, 1971; Marincovich, 1973; Ramirez, 1974;

Hockey et al., 1987; Espoz et al., 1995). The present form is

identified as S. ceciliana, since it corresponds with d’Orbigny’s

(1841) description and figure (the types are lost), and resembles

specimens from the type locality in the Falkland Islands (NHM). This

species is one of several which, when strongly eroded at the apex, can

show a striking mimetic resemblance to a large barnacle. This is

achieved by the exposure of the dark brown and streaked shell layers

beneath the myostracum, which produces a pattern resembling the

tergal and scutal plates of a barnacle (Hockey et al., 1987). Erosion of

the shell is facilitated by the lichen Thelidium litorale (Espoz et al.,

1995). In the present samples of S. ceciliana only a few specimens

show this erosion pattern, and in these the mimicry is less striking

than in Scurria species from further north on the Chilean coast.

Scurria parasitica (d’Orbigny, 1841)

(Figure 2F, G)

Patella parasitica d’ Orbigny, 1841: 481, pl. 81, figs 1-3.

Scurria parasitica —Marincovich, 1973: 21—22, fig. 37 (synonymy).

DESCRIPTION. Shell to 15 by 13 mm, height 8 mm; high conical to

tall cap-shaped, apex at one third of shell length from anterior

margin; outline oval to almost round; plane of base often curved to

fit shell substrate; radial sculpture weak, of fine striae, often eroded

away or obsolete, occasionally developing weak radial ribs; colour

variable, often varying in concentric zones on the same shell,

usually with 13-20 broad radial white stripes, with brown or black

marbled or lineated sectors between; may be uniformly blackish

brown, or flecked with white; interior white with irregular brown

spatula, external pattern showing through at margin.

HABITAT. Onshells of large molluscs (Nacella, Acanthina, Mytilus)

in eulittoral, on sheltered and moderately exposed shores; also on

shell material on eroding edge of large midden. In central and

northern Chile the species reaches larger size (29 mm) and inhabits

large chitons, Fissurella and other Scurria species (d’Orbigny,

1841; Marincovich, 1973).

RECORDS. Stations 1, 7, 10, 12, 14. Elsewhere Callao (Peru)

(NHM), Chincha Is (Peru) to Talcahuano (Marincovich, 1973),

extended southwards by the present records. Range: 12-46°S.

Family FISSURELLIDAE

Puncturella (Puncturella) conica (d’ Orbigny, 1841)

(Figure 7B)

Rimula conica d’ Orbigny, 1841: 471, pl. 78, figs 10, 11.

Puncturella conica — Powell, 1951: 86-87 (synonymy). Powell,

1960: 127. Dell 1971: 178-179, pl. 5, figs 10, 11, 14, 15 (syn-

onymy). Arnaud, 1972: 113-114. Castellanos & Landoni, 1988:

20, pl. 3, fig. 1

Puncturella cognata (Gould, 1852) — Powell, 1951: 86. Linse, 1997:

Di.

Puncturella spirigera Thiele, 1912 — Powell, 1960: 127. Dell, 1990:

76, figs 125, 127.

120

DESCRIPTION. Shell 5.5 by 4.0 mm, height 3.5 mm (to 16 mm in

length, Powell, 1951); tall cap-shaped with coiled apex; short longi-

tudinal slit just anterior to shell apex; sculpture of 25 radial ribs

made scaly by growth lines, with a smaller riblet in each interspace;

white.

HABITAT. Single dead shell dredged in 10-15 m, on substrate of

cobbles encrusted with calcareous red algae, near shore in sheltered

bay. Dell (1971) recorded the species from 6—20 m in southern

Chile, Powell (1951) from 60-342 m, and Dell (1990) to 2804 m in

the Ross Sea (if the synonymy with P. spirigera is accepted).

RECORDS. Station 7 (single dead shell). Elsewhere I. Chiloé (Dell,

1971) to Magellan Strait, also Falkland Is (Powell, 1951) and

perhaps circum-Antarctic (Dell, 1990). Range: 42—75°S.

REMARKS. Thetaxonomy of the southern species of P. (Puncturella)

is unclear, and critical revision is required (Dell, 1990). They are

closely similar to P. (P.) noachina (Linnaeus, 1771) from the north-

ern Pacific and Atlantic Oceans, but are usually regarded as

specifically distinct. The single shell found has been compared with

the holotype (NHM) from the Falkland Islands, and closely resembles

it in size and sculpture, although slightly less acutely conical.

Previous authors differ in the number of species recognized in this

group, according to their interpretation of differences in shell shape

and degrees of sculpture. However, in view of the intraspecific

variation in these features described in South African specimens by

Herbert & Kilburn (1985), it is possible that only a single species

may be involved.

Fissurella (Fissurella) nigra Lesson, 1831

(Figure 3A)

Fissurella nigra Lesson, 1831: 412-413. Osorio, Atria & Mann,

1979: 17, fig. 13. Castellanos & Landoni, 1988: 15, pl. 2, fig. 5.

Oliva & Castilla, 1992: fig. 9.

Fissurella (Fissurella) nigra — McLean, 1984: 52-55, figs 200-211

(synonymy).

DESCRIPTION. Shell to 104 by 75 mm, height 40 mm (maximum

length 140 mm, Bretos,Quintana & Ibarrola, 1988); outline elongate

oval, narrowed anteriorly, base resting flat, foramen slightly anterior

of centre; sculpture almost smooth in large shells, except for concen-

tric growth lines, but with numerous fine radial ribs in juveniles;

colour purple-black, foramen outlined in white (eroded to reveal

inner aragonitic shell layer); interior white, margin (external calcitic

layer) of outer black and inner translucent gray zone; head and

tentacles black, sides of foot dark grey to black, with a row of small

white tubercles.

HABITAT. Common beneath rocks on sheltered and moderately

sheltered boulder and rocky shores, in mid to low eulittoral zone. Fre-

quently in groups of up to 7 individuals under a single rock. A similar

habitat was reported by McLean (1984), but it can also be found in the

immediate subtidal zone (Bretos, Quintana & Ibarrola, 1988).

RECORDS. Stations 1, 7, 14, 15, 20, 21. Elsewhere Valparaiso to I.

Navarino (McLean, 1984). Range: 33-55°S.

REMARKS. All the Chilean Fissurella species are edible, and the

D.G. REID AND C. OSORIO

total extraction for 1997 was 3063 tonnes (SERNAP, 1998).

Fissurella (Fissurella) oriens oriens Sowerby, 1835

(Figure 3C)

Fissurella oriens Sowerby, 1835: 124.

Fissurella (Fissurella) oriens oriens — McLean, 1984: 49-52, figs

178-199 (synonymy).

Fissurella oriens oriens — Castellanos & Landoni, 1988: 14, pl. 2,

figs 10, 11.

DESCRIPTION. Shell to 54 by 30 mm, height 12 mm (maximum

length 70 mm, McLean, 1984); outline more or less narrowly oval,

narrowed anteriorly, either sides or ends of shell slightly raised when

on flat surface, foramen almost central; sculpture smooth, or with

very fine indistinct striae in young shells; colour variable, white to

pink, often with broad purple grey rays (not divided into lines), but

pattern may be absent; interior white with narrow translucent mar-

gin; animal pale, head grey, sides of foot mottled pink and grey,

tentacles and mantle margin yellowish.

HABITAT. Under rocks and in rock pools, in lowest eulittoral, on

moderately sheltered and moderately exposed shores; juveniles

found in holdfasts and on fronds of Macrocystis, 10-15 m depth.

Unidentified fissurellids made up the major molluscan component

of the invertebrate biomass associated with Macrocystis holdfasts in

the Beagle Channel (Ojeda & Santelices, 1984). McLean (1984)

recorded this species from the lower intertidal to 30 m depth.

RECORDS. Stations 1, 5,9, 14, 17. Elsewhere Valparaiso to Tierra

del Fuego, of which specimens north of about 37°S belong to the

subspecies F. o. fulvescens Sowerby (McLean, 1984). Total range:

33-56°S.

REMARKS. This species is distinguished from the similar F: picta

by its lack of radial ribs and by its paler, yellowish animal, and

occupies a lower and more sheltered habitat. According to the

detailed monograph of the Magellanic species of Fissurella by

McLean (1984), an additional species, F. radiosa Lesson, 1831,

occurs in the region and, although similar to F. oriens, can be

distinguished by its strong radial ribs.

Fissurella (Fissurella) picta picta (Gmelin, 1791)

(Figure 3B)

Patella picta Gmelin, 1791: 3729.

Fissurella (Fissurella) picta picta — McLean, 1984: 37-43, figs

123-146 (synonymy).

Fissurella picta—Osorio, Atria & Mann, 1979: 16, fig. 11. Castellanos

& Landoni, 1988: 1, pl. 2, figs 3, 4. Oliva & Castilla, 1992: fig. 3.

DESCRIPTION. Shell to 88 by 56 mm, height 32 mm; outline

narrowly oval, narrowed anteriorly, sides slightly raised when on

flat surface, foramen slightly anterior of centre; sculpture of sharp

narrow ribs of varying size, and irregular concentric growth lines;

colour white to grey, with broad purple-black rays, each divided into

several dark lines; interior white, margin (external calcitic layer)

Fig.3 A. Fissurella (Fissurella) nigra (76 mm). B. Fissurella (Fissurella) picta picta (60 mm). C. Fissurella (Fissurella) oriens oriens (53 mm).

D. Margarella violacea (7.1 mm). E. Diloma nigerrima (18 mm). F, G. Crepidula dilatata (sensu lato) (72 mm). H, I. Trochita trochiformis (54 mm).

J. Tegula (Chlorostoma) atra (30 mm). K. Acanthina monodon (form monodon from exposed shore at station 14; 46 mm). L. Acanthina monodon (form

unicornis from sheltered shore at station 1; 57 mm). M. Argobuccinum (Argobuccinum) pustulosum ranelliforme (78 mm). N. Trophon plicatus (51 mm).

O. Concholepas concholepas (94 mm). (All specimens from study area; NHM collection).

MOLLUSCA OF SOUTHERN CHILE

122

showing external rayed pattern; head and tentacles dark grey to

black, sides of foot dark grey, densely mottled with white tubercles.

HABITAT. On rock and in crevices, from mid eulittoral Mytilus

zone to lowest eulittoral, on exposed coasts. Common in super-

ficially bare grazed zone between Mytilus zone above and calcareous

red algal zone of sublittoral fringe, on moderately exposed cliffs,

together with Nacella magellanica, Chiton granosus and Tegula

atra. This is an abundant species in southern Chile, reaching densi-

ties of 17 per m? in areas protected from humans (Jara & Moreno,

1984) and occurring in the mid to low eulittoral on both exposed and

sheltered coasts (Bretos, Gutiérrez & Espinoza, 1988; Godoy &

Moreno, 1989). It is restricted to the intertidal zone (McLean, 1984).

RECORDS. Stations 5, 9, 13, 14, 17. Elsewhere the species occurs

from Valparaiso to Tierra del Fuego, with overlap between the

nominate, southern subspecies and the northern F: p. lata Sowerby

on I. Chiloé (McLean, 1984). Total range: 33-56°S.

REMARKS. This species is the major herbivore of the mid and low

shore on exposed rocky coasts in southern Chile, grazing principally

on Iridaea. It is one of the main species in commercial limpet

catches. In the vicinity of human settlements, where collection

pressure on this species is strong, algae proliferate on the shore.

However, when humans were excluded from a shore near Valdivia

the density of F picta increased to 3 per m* and algal cover was

reduced (Moreno & Jaramillo, 1983; Moreno, Sutherland & Jara,

1984; Duarte, Asencio & Moreno, 1996). On the more remote

shores of the present study area the density of F. picta remains high

in suitable habitats of moderate wave exposure, and grazing pres-

sure by this and other herbivores appears to result in a low eulittoral

zone without large macroalgae.

Family TROCHIDAE

Tegula (Chlorostoma) atra (Lesson, 1831)

(Figure 3J)

Trochus ater Lesson, 1831: 344, pl. 16, fig. 2, 2’.

Chlorostoma atra — Dell, 1971: 195 (synonymy).

Tegula (Chlorostoma) atra — Marincovich, 1973: 24, fig. 42 (syn-

onymy).

Tegula atra—Osorio, Atria & Mann, 1979: 17-18, fig. 14. Castellanos

& Landoni, 1989: 27, pl. 4, fig. 4.

DESCRIPTION. Shell to 39 by 41 mm (to 57 mm, Osorio et al.,

1979); trochoidal with rounded periphery; surface smooth; no um-

bilicus, blunt tooth at base of columella; colour dull purple black

above, apex often eroded, base whitish; interior nacreous.

HABITAT. Abundant on rocky shores of sheltered and moderate

exposure; on and under cobbles, boulders and on cliffs; mid to low

eulittoral, from Mytilus zone to zone of calcareous red algae in

sublittoral fringe, and an important herbivore of the bare, grazed belt

between these two zones on moderately exposed cliffs; rarely

sublittoral (one specimen from 7—9 m, station 22); rare at station 22

where salinity was recorded as 15—21%c. In central and northern

Chile this species is typical of the Lessonia and Lithothamnion zone

of the sublittoral fringe, on sheltered and moderately exposed coasts

(Guiler, 1959a, b; Marincovich, 1973; Ruiz & Giampaoli, 1981).

RECORDS) Stations [enon 7a en LOS 2 AS ale O lee

Elsewhere Pacasmayo (Peru) to Magellan Strait (Marincovich, 1973).

Range: 7—54°S.

D.G. REID AND C. OSORIO

REMARKS. This is an edible species; the national harvest in 1997

was 159 tonnes (SERNAP, 1998).

Diloma nigerrima (Gmelin, 1791)

(Figure 3E)

Turbo nigerrimus Gmelin, 1791: 3597.

Diloma nigerrima — Dell, 1971: 195-197, pl. 1, fig. 8, pl. 2, fig. 2

(synonymy). Marincovich, 1973: 23-24, fig. 45. Powell, 1979:

53. Castellanos & Landoni, 1989: 29, pl. 4, fig. 6.

DESCRIPTION. Shell to 21 by 19 mm; turbinate; sculptured with

indistinct spiral grooves, stronger on spire whorls, strongest groove

just below suture; colour dull purple black, including base, apical

whorls often eroded to reveal nacre; interior nacreous.

HABITAT. Abundant in clusters beneath stones in upper eulittoral,

on moderately sheltered cobble and boulder shores. A similar

habitat was noted by Dell (1971) and Brattstrém (1990) on I. Chiloé,

with additional records from the mid and low eulittoral; in northern

Chile Marincovich (1973) recorded it in clusters in the lower

intertidal zone.

RECORDS. Stations 7, 8. Elsewhere Salaverry (Peru) to Magellan

Strait (Marincovich, 1973). The same (Powell, 1979) or a closely

related species (Dell, 1971) occurs in New Zealand. Range: 8-54°S.

REMARKS. This species was found at only two stations, where it

was abundant and found at levels above those occupied by the

superficially similar Tegula atra.

Margarella violacea (King & Broderip, 1832)

(Figure 3D)

Margarita violacea King & Broderip, 1832: 346. Sowerby, 1838:

24.

Photinula violacea — Strebel, 1905a: 145-152, pl. 5, figs 1-8, 12, 13.

Margarella violacea — Powell, 1951: 96. Deambrosi, 1969: 51-52,

fig. 1 (radula). Dell, 1971: 194 (synonymy). Castellanos &

Landoni, 1989: 16, pl. 3, fig. 4.

Promargarita violacea — Dell, 1990: 77-78.

DESCRIPTION. Shell to 6.0 by 6.7 mm (to 10.3 by 11.5 mm, Dell,

1971); trochoidal with rounded whorls, umbilicus minute or closed;

surface smooth, shining; colour iridescent violet pink, white around

umbilicus; interior nacreous; operculum corneous.

HABITAT. Dredged from 10-15 m depth, on substrates of cobbles

with encrusting calcareous red algae, silt with scattered pebbles and

shells, and shell gravel. Not common. In the original description it

was noted that this species is found on the fronds of Macrocystis in

the Magellan Strait (King & Broderip, 1832), and it has also been

recorded from both fronds (Dell, 1971; Castilla, 1985) and holdfasts

(Ojeda & Santelices, 1984) of kelp in the Beagle Channel; it was not

found on MacrocysStis in our survey. Dell (1971) recorded specimens

from the intertidal and to a depth of 12 m.

RECORDS. Stations 7, 14, 25. Elsewhere Puerto Eden to Tierra del

Fuego, also Falkland Is (Dell, 1971), so that ours are the most

northerly records. Range: 46—-55°S.

REMARKS. Confusion surrounds the specific identification, generic

assignment and relationships of the Magellanic and Antarctic species

variously classified in Margarites, Margarita, Margarella and

Promargarita. The present specimens are smaller and have a slightly

lower rate of whorl expansion than the types of the species (NHM)

from the Magellan Strait, although shape is evidently variable

MOLLUSCA OF SOUTHERN CHILE

(Strebel, 1905a). The bright pink coloration of the shell fades in

museum specimens, and this species is then more difficult to separate

from the similar Margarella expansa (Sowerby, 1838); when fresh,

the latter is usually olive in colour, with a vivid green iridescence on

the spire whorls, and the shape is lower-spired with a more expanded

final whorl (Strebel, 1905a; Powell, 1951). In a revision of the

suprageneric classification of trochoideans, Hickman & McLean

(1990) used acombination of gill and radular characters to distinguish

the Margaritinae (including Margarites, mainly from high latitudes of

the northern hemisphere) and Gibbulini of the Trochinae (including

Margarella from southern high latitudes). However, they pointed out

that both radular types can be found among the southern species, and

that a revision is required. Using a different radular character,

Deambrosi (1969) segregated two groups among the southern species,

for which the names Margarella and Margarites were used, although

the relationship with northern forms was not addressed. Later, Dell

(1990) noted that the type species of Margarella in fact belonged to the

‘Margarites’ group, and therefore used the next available generic

name, Promargarita, for the former. Until these relationships are

resolved, we have retained the familiar generic name Margarella.

Family TURBINIDAE

Homalopoma cunninghami (Smith, 1881)

(Figure 7F)

Collonia cunninghami E.A. Smith, 1881: 33, pl. 4, figs 10, 10a.

Homalopoma cunninghami — Dell, 1971: 193-194 (synonymy).

Castellanos & Landoni, 1989: 31, pl. 2, fig. 2, pl. 4, fig. 7.

DESCRIPTION. Shell to 3.9 by 4.6 mm; globular; surface with fine

spiral grooves, small umbilicus in young shells, becoming closed in

adults; colour dark pink to magenta; interior nacreous; operculum

calcified externally.

HABITAT. Dredged from 10—15 m depth, on substrates of cobbles

with encrusting calcareous red algae, and on pebbles with shell

gravel. Recorded from 66 m depth by Powell (1951).

RECORDS. Stations 7, 14. Elsewhere I. Chiloé to Magellan Strait

(Dell, 1971) and Tierra del Fuego (Powell, 1951). Range: 43-55°S.

REMARKS. Superficially this speciesresembles Margarellaviolacea,

with which it is found, but is distinguished by its pink (not violet)

coloration, spirally striated surface and calcified operculum. The

thickness of calcification on the operculum is apparently variable,

being thick only at the margin and thinner centrally in the present

specimens, although thick over the whole surface in the types (NHM).

Family LITTORINIDAE

Nodilittorina araucana (dq Orbigny, 1840)

(Figure 7C)

Littorina araucana qd Orbigny, 1840: 393, pl. 53, figs 8-10.

Littorina (Austrolittorina) araucana — Marincovich, 1973: 25, figs

48, 49 (synonymy).

Nodilittorina (Nodilittorina) araucana — Reid, 1989: 99.

DESCRIPTION. Shell to 12 by 7 mm; tall conical, solid; smooth or

with fine spiral lines, but spire whorls usually eroded; colour purple

black to purple brown; aperture black with basal white stripe.

HABITAT. Locally abundant, among uppermost barnacles and the

crustose red alga Hildenbrandia in upper eulittoral on moderately

123

exposed shores. Sometimes on algal rocks, shell midden material

and among Mytilus, in upper and mid eulittoral on sheltered shores.

In central and northern Chile this species is also typical of the upper

eulittoral barnacle zone on exposed coasts (Ruiz & Giampaoli,

1981; Santelices, 1991), although Marincovich (1973) observed

that, while generally common, it was absent from strongly exposed

shores at Iquique. Dell (1971) and Brattstr6m (1990) recorded this

species from throughout the littoral zone.

RECORDS. Stations 1, 10, 12, 14. Elsewhere Salaverry (Peru) to I.

Chiloé (D.G. Reid, unpublished), Canal Moraleda (45°S; Brattstrom

& Johanssen, 1983), extended southwards by the present records.

Range: 8-46°S.

REMARKS. Although very abundant on some shores, this species

had an unpredictable occurrence in the Estero Elefantes. The pelagic

egg capsules and planktotrophic reproduction of this species were

described by Jordan & Ramorino (1975).

Family CALYPTRAEIDAE

Crepidula dilatata Lamarck, 1822 [sensu lato]

(Figure 3F, G)

Crepidula dilatata Lamarck, 1822: part 2: 25.

Crepipatella dilatata — Marincovich, 1973: 32, fig. 66 (synonymy).

Castellanos, 1990: 13, pl. 2, fig. 18 a—c.

Crepidula dilatata — Gallardo, 1977: 241-251 (development).

Gallardo, 1979: 215-226, fig. 1 (synonymy).

Crepidula dilatata — Hoagland, 1977: 372 (synonymy).

Crepidula fecunda Gallardo, 1979: 215-226, fig. 2.

DESCRIPTION. Shell to 72mm; irregularly oval to circular; marginal

apex, twisted to right side; smooth; colour often entirely white;

otherwise pinkish and marked externally with numerous fine radiat-

ing lines of purple brown and one central white stripe, interior

variously marked with pinkish purple, septum white; animal greyish

white, sides of foot, neck, head and mantle margin dark grey to black.

HABITAT. Common in pools and under rocks on rocky shores of

moderate exposure; under stones on sand in lower eulittoral of

sheltered bay; dredged on shell fragments to 15 m depth (to 18 m,

Dell, 1971); on pebbles in shallow tidal channels. Found in maxi-

mum abundance densely packed on subtidal rocks at depths of up to

2 m, in entrance of lagoon with strong tidal currents (station 11). At

Isla Chiloé Brattstr6m (1990) recorded it commonly in the lower

eulittoral zone. This species is a common epibiont on Aulacomya

atra and large barnacles (Marincovich, 1973; Gallardo, 1979).

RECORDS. Stations 1, 11, 12, 14, 15, 20. Elsewhere I. Lorenzo

(Peru) to Punta Arenas (Marincovich, 1973), possibly as far north as

Mazatlan (Mexico) (23°N) (Hoagland, 1977). Range: 12—53°S.

REMARKS. Gallardo (1979) has shown that two sibling species can

be recognized within this taxon, C. dilatata s.s. and C. fecunda, on

the basis of their larval development. In C. dilatata s.s. the veliger

larvae develop within the egg capsule, feeding on nurse eggs, and

hatch as juveniles, whereas in C. fecunda planktonic veligers hatch

from the capsule (Gallardo, 1977). Morphologically, the shells and

animals of these two species are too similar for reliable identifica-

tion, although C. dilatata is often white with a grey animal, whereas

C. fecunda has a pink shell of larger size and a more darkly

pigmented animal (Gallardo, 1979). No egg capsules were collected

during the present survey and the available material displays aspects

of both species. The large size attained (72 mm) and the generally

124

black coloration of the animal suggest C. fecunda, although the

shells are frequently white as in C. dilatata. At station 12 it was

found that specimens from beneath rocks had white, circular shells

and lightly-pigmented, predominantly yellow animals, whereas those

from the sides of rock pools had purple, oval shells and black

animals; it is not known whether these forms represent the two

species. Gallardo (1979) noted that the two were often sympatric in

the fjords of southern Chile, but that C. dilatata was the more

common. Large shells were moderately common in the ancient shell

middens on Isla Traiguén.

Trochita trochiformis (Born, 1778)

(Figure 3H, I)

Turbo trochiformis Born, 1778: 355.

Calyptraea (Trochita) trochiformis — Keen, 1971: 456, fig. 804.

Marincovich, 1973: 31-32, fig. 65.

Trochita radians (Lamarck, 1822) — Rehder, 1943: 42-43, fig. 1

(synonymy).

DESCRIPTION. Shell to 54 mm; circular with central apex; sculp-

ture of numerous sharp radial ribs; colour white, internally white

stained with dark brown; animal unpigmented.

HABITAT. Attached to undersides of stones closely appressed to

silty sediment in large tidal pool, in sublittoral fringe, sheltered from

wave action, common (station 14); also under stones on moderately

exposed rocky shores. In the north of Chile this species lives on

wave-exposed coasts (Marincovich, 1973), on both intertidal and

subtidal rock substrates (Canete & Ambler, 1992).

RECORDS. Stations 12, 14. Elsewhere Manta (Ecuador) to

Valparaiso (Rehder, 1943; Keen, 1971) and Canal Chacao (41°50°S;

Brattstrom & Johanssen, 1983). The present records extend the

confirmed range of this species. In addition, it has been mentioned

from Tierra del Fuego and the Magellan Strait (Carcelles &

Williamson, 1951), but confusion with the Magellanic species T.

pileus (Lamarck) is likely. Range: 1-46°S.

REMARKS. The worldwide distribution of the five recognized

living Trochita species shows a strong association with cold upwelling

systems or (in the Magellanic 7. pileus) with cold currents (Taylor &

Smythe, 1985). The present records extend the distribution of 7.

trochiformis considerably beyond the upwelling zones on the Chil-

ean coast, which extend only to 41°S (Brattstrom & Johanssen,

1983). Another peculiarity of these records is the unexpectedly

sheltered microhabitat under stones, and even resting on silt. Else-

where, this and the two most closely related species, T. spirata

(Forbes) and T: dhofarensis Taylor & Smythe, are found in the low

eulittoral and shallow sublittoral on rocky coasts exposed to strong

wave action (Marincovich, 1973; Taylor & Smythe, 1985; D.G.Reid

pers. obs. in Mexico and Cabo Verde). The intracapsular develop-

ment of T. trochiformis has been described by Caftete & Ambler

(1992). This edible species was occasionally found in shell middens

on Isla Traiguén.

Family LAMELLARIIDAE

Lamellaria ampla Strebel, 1906

Lamellaria ampla Strebel, 1906: 145-146, pl. 11, figs 70, 71.

Castellanos, 1990: 27, pl. 1, figs 9, 10.

DESCRIPTION. Animal 12 mm (to 32 mm, Strebel, 1906), shell 9

D.G. REID AND C. OSORIO

mm (to 19 mm, Strebel, 1906); shell fragile, transparent, auriculiform

with small, low spire and enlarged, oval aperture; shell entirely

covered by smooth mantle with oval outline and anterior notch,

broadly overlapping the foot; in life mantle is orange yellow with

indistinct dark markings; penis with conspicuous lateral flange and

small terminal filament.

HABITAT. Single animal dredged from 10-15 m, on bottom of silt

with scattered pebbles. Dredged from 40 m in Beagle Channel

(Linse, 1997).

RECORDS. Station 25. Elsewhere Beagle Channel (Strebel, 1906;

Linse, 1997). Range: 46—-55°S.

REMARKS. The identification of this single specimen is tentative,

and based on the form of the shell. Of the four species illustrated by

Strebel (1906) and one by Smith (1881), L. ampla is the only one

with a low-spired auriculiform shape as in the present example.

However, the form of the penis is somewhat different from that

outlined by Strebel (1906: pl. 11, fig. 70C). Marcus (1959: 85-86)

listed the names of 12 lamellariids reported from Chile and noted

that many were poorly known anatomically; this remains true and a

thorough revision is necessary. Members of the genus Lamellaria

prey upon ascidians.

Family RANELLIDAE

Argobuccinum (Argobuccinum) pustulosum ranelliforme

(King & Broderip, 1832)

(Figure 3M)

Triton ranelliformis King & Broderip, 1832: 347.

Argobuccinum ranelliforme — Smith, 1970: 462-466, pl. 39, figs 2,

4, 6, 9, pl. 40, figs 2, 6, 7, 10-12, textfigs 2b, 5.

Argobuccinum (Argobuccinum) pustulosum ranelliforme — Beu,

1985a: 56.

Argobuccinum (Argobuccinum) argus — Carcelles, 1954: 244-246,

figs 5, 6 (not Gmelin, 1791, which is the nominate subspecies).

DESCRIPTION. Shell to 82 mm: whorls rounded, two indistinct

varices per whorl; sculptured by low spiral ribs intersecting with

weak axial ribs to produce beaded sculpture, most pronounced on

spire whorls, becoming obsolete on last 1-2 whorls; colour cream

with chocolate brown ribs, interior white.

HABITAT. Common on beds of Mytilus in mid to low eulittoral

zone, and in zone of coralline red algae in sublittoral fringe, on

shores of moderate to strong wave exposure.

RECORDS. Stations 5, 14, 17. Elsewhere Caldera to Tierra del

Fuego (Carcelles, 1954; Smith, 1970). Range: 27—55°S.

REMARKS. This is a large, edible species, of which 277 tonnes

were collected nationally in 1997 (SERNAP, 1998). The diet con-

sists of crustaceans and echinoids (Smith, 1970), and the egg

capsules of the nominate subspecies from South Africa have been

described (Kilburn & Rippey, 1982: 75-76).

Family CERITHIOPSIDAE

Eumetula pulla (Philippi, 1845)

(Figure 7D)

Cerithium pullum Philippi, 1845: 66-67. Strebel, 1905b: 652-655,

pl. 23, fig. 40a—d.

Ataxocerithium pullum — Powell, 1951: 111-112, fig. I, no. 34

MOLLUSCA OF SOUTHERN CHILE

(radula), fig. N, no. 102 (protoconch) (synonymy). Castellanos,

1990: 8, pl. 2, figs 18, 21.

Eumetula pulla — Bouchet & Warén, 1993: 601.

DESCRIPTION. Shell to 8.8 by 3.5 mm (to 13 mm, Castellanos,

1990); narrowly elongate, thin-walled; spire whorls encircled by

three spiral rows of square nodules, aligned in axial rows, two spiral

ribs lacking nodules below periphery of last whorl; colour brown,

spiral rows of nodules darker.

HABITAT. Dredged from 10-15 m depth, on substrate of silt with

scattered pebbles and shells; uncommon. The species has been

reported from depths of 8 to 251-313 m (Powell, 1951). Other

members of the genus are known to live and feed on sponges, as do

most cerithiopsids (Houbrick, 1987), and this may be the typical

habitat of E. pulla also; one collection ‘in sponge’ was noted by

Melvill & Standen (1912).

RECORDS. Station 25 (1 dead, 2 live specimens). Elsewhere

Magellan Strait, Falkland Is and Burdwood Bank (Powell, 1951), so

that our records are the northernmost. Range: 46-54°S.

REMARKS. The more familiar genus Ataxocerithium has usually

been classified in the Cerithiidae, but was transferred to the

Cerithiopsidae by Houbrick (1987). Bouchet & Warén (1993) trans-

ferred this species to the cerithiopsid genus Eumetula on the basis of

radular characters.

Family MURICIDAE

Concholepas concholepas (Bruguiére, 1789)

(Figure 30)

Buccinum concholepas Bruguieére, 1789: 252.

Concholepas concholepas — Beu, 1970: 44, pl. 4, figs 10-12. Dell,

1971: 210-211. Marincovich, 1973: 35, fig. 73. Osorio, Atria &

Mann, 1979: 21-22, fig. 23. Kool, 1993: 173-176, fig. 7A-F.

DeVries, 1995: 286, figs 4, 6, 8, 9, 11, 19 (synonymy).

Concholepas concholepas concholepas — Stuardo, 1979: 5—38, pl. 1,

figs 1-8, pl. 3, figs 17, 23 (synonymy).

DESCRIPTION. Shell to 108 mm; body whorl greatly expanded to

produce limpet-like form; sculptured by coarse spiral ribs, imbri-

cated by raised axial growth lines; colour brown, interior white with

brown margin.

HABITAT. In rock crevices at top of calcareous red algal zone,

| lowest eulittoral, on strongly exposed coast. In central Chile and

| further north, adult populations are mainly subtidal, reaching depths

of 40 m (Rabi, Yamashiro & Quiroz, 1996), but the rarity of adults

_ in the littoral zone appears to be a consequence of exploitation by

humans. In reserves where this is prevented, large adults appear in

| the littoral zone and density may increase to as many as 1.6—4.3 per

m? (Castilla & Durén, 1985; Moreno, Lunecke & Lepez, 1986;

| Duran, Castilla & Oliva, 1987). Settlement occurs in the low

| eulittoral, and juveniles move upwards as growth occurs (Moreno,

|) Reyes & Asencio, 1993).

RECORDS. Station 16. Elsewhere I. Lobos de Afuera (Peru) to

| Cape Horn (DeVries, 1995). Range: 7-55°S.

| REMARKS. This large species supports the most important gastro-

| pod fishery in Chile (Castilla, 1982); the catch has declined from

| 21236 tonnes in 1987 to 3154 tonnes in 1997 (SERNAP, 1998) and

collection is now permitted for only a few days in the year. It is a

| common component of the ancient shell middens on Isla Traiguén.

125

Collection by fishermen continues in the study area, but the intensity

of exploitation is not known, nor to what extent this might influence

the absence of this species from the more accessible coasts of

moderate exposure. The egg capsules are cylindrical and stalked, 25

mm long; these have been described by Castilla & Cancino (1976)

and the planktotrophic development of the larvae by DiSalvo (1988).

This carnivorous species has a diet of barnacles, the ascidian Pyura,

Perumytilus and other molluscs (Castilla, Guisado & Cancino,

1979; Castilla & Duran, 1985) and is able to bore into its shelled prey

(Gruber & Carriker, 1990). As a top predator it has an important

influence on community structure, and where human collection is

prevented the cover of barnacles and Perumytilus declines signifi-

cantly (Moreno, Lunecke & Lepez, 1986). There is a large literature

on this species, reviewed by Rabi, Yamashiro & Quiroz (1996). The

taxonomic status of the population on the Juan Fernandez Islands,

described as the subspecies C. concholepas fernandezianus Stuardo,

1979, requires investigation.

Acanthina monodon (Pallas, 1774)

(Figure 3K, L)

Buccinum monodon Pallas, 1774: 33, pl. 3, figs 3, 4.

Acanthina monodon — Dell, 1971: 208-210 (synonymy).

Cernohorsky, 1977: 118 (synonymy). Osorio, Atria & Mann,

ISTO SA hie: 20"

Acanthina monodon monodon — Wu, 1985: 56-58, figs 13, 14, 24,

34, 52-58, 71 (radula, anatomy). Vermeij, 1993: 22.

Acanthina monodon unicornis (Bruguiére, 1789) — Vermeij, 1993:

22,

Acanthina crassilabrum (Lamarck, 1816) — Dell, 1971: 210 (syn-

onymy).

Acanthina monodon crassilabrum — Wu, 1985: 58-61, figs 15-17,

23, 35-37, 50, 51, 59, 71 (radula, anatomy).

DESCRIPTION. Shell to 57 mm; whorls rounded, spire pointed;

usually sculptured by 20-30 raised spiral cords, often imbricated by

raised axial growth lines; sculpture may be obsolete on body whorl,

or eroded; outer apertural lip sharp, or thickened and with internal

denticles, always with labral spine near anterior end of outer lip;

colour polymorphic: purple brown, white, orange or banded with

brown.

HABITAT. Eulittoral rocky shores, in lower barnacle zone and

Mytilus zone, in exposed and moderately sheltered situations. Found

at salinities down to 15 and 22%o.

RECORDS. Stations 1,5,7, 10, 12, 14, 15, 17, 20, 21, 22. Elsewhere

from about 22°S to Magellan Strait (Dell, 1971) and Tierra del

Fuego (Wu, 1985). Range: 22—55°S.

REMARKS. This was one of the most frequent intertidal gastro-

pods in the study area. Members of this species are carnivorous,

and small mussels are a major component of the diet (Moreno,

1995). The related Californian genus Acanthinucella feeds mainly

on barnacles, which are attacked either by using the labral spine to

prise or wedge open the opercular valves before inserting the

proboscis, or alternatively by boring through the valves by means

of the accessory boring organ and radula (Malusa, 1985; Perry,

1985). The egg capsules are small and flask-shaped, 15 mm in

length, and laid in batches in crevices on the shore (Wu, 1985: figs

52, 53). The shell is remarkably variable in shape and sculpture,

showing a much thicker, smoother shell with narrower aperture

and stronger marginal denticles (Fig. 3L) in sheltered habitats, in

contrast to a thinner, scaly shell in exposed situations (Fig. 3K).

Similar variation occurs over a geographical scale, and some

126

authors have distinguished a relatively smooth, northern species or

subspecies A. m. unicornis (Bruguiére, 1789) (= A. crassilabrum)

from the typical southern A. m. monodon with scaly spiral cords,

thinner shell and wider aperture (Dell, 1971; Wu, 1985; Vermeij,

1993). The two forms are said to overlap between 40 and 44°S and

have been recorded sympatrically (Dell,1971; Wu, 1985), although

characters evidently intergrade in this region (Cernohorsky, 1977;

Wu, 1985). The present samples extend the geographical range of

this overlap; both shape and sculpture vary such that no clear

distinction can usefully be made on the basis of these characters,

and the two forms are provisionally regarded as conspecific until

more evidence becomes available. As in the similar ocenebrine

muricid Nucella (e.g. Palmer, 1990), shell form might be a func-

tional phenotypic response to the presence of crab predators, from

which the snails are at greater risk on shores protected from wave

action. Possible correlation of shell form with abundance of preda-

tory crabs on local and geographical scales has not been

investigated in A. monodon. However, it is notable that several

intertidal Littorina species in the northern Atlantic show analogous

variation in shell characters over a geographical scale, with thin-

shelled forms present only at high latitudes where predatory crabs

are rare or absent, producing a stepped cline (Reid, 1996).

Trophon plicatus (Lightfoot, 1786)

(Figure 3N)

Trophon laciniatus (Martyn, 1784) — Strebel, 1904: 199-203, pl. 3,

figs 1-8 (non-binominal and therefore unavailable name).

Trophon (Stramonitrophon) laciniatus (Martyn, 1784) — Powell,

1951: 156.

Murex plicatus Lightfoot, 1786: 104.

Trophon plicatus — Cernohorsky, 1977: 117, fig. 18.

Trophon (Stramonitrophon) plicatus — Castellanos & Landoni, 1993:

5, pl. 1, figs 16-22.

Trophon (Stramonitrophon) lamellosa (Gmelin, 1791) — Dell, 1971:

212 (synonymy).

DESCRIPTION. Shell to 54 mm; fusiform with rounded whorls;

sculptured by prominent, lamellose varices (10-15 on last whorl),

each produced to a point on shoulder; colour white, eroded to

purplish grey, interior purple.

HABITAT. In sheltered tidal pool, just sublittoral, under stones on

silt; in rock pool with Mytilus in low eulittoral on moderately

exposed shore (station 14); dredged from 10-15 m on bottom of silt

with scattered pebbles and shells (station 25). To 88 m depth

(Powell, 1951).

RECORDS. Stations 14, 25. Elsewhere above 49°S to Tierra del

Fuego (Dell, 1971), extended northward by the present records.

Range: 46-54°S.

REMARKS. The brachiopod Magellania venosa was abundant in

the dredge samples from station 25, in which both this species and

Xymenopsis muriciformis occurred. A few of the brachiopods showed

boreholes in their shells, which may have been drilled by one or

other of these two muricids.

Xymenopsis muriciformis (King & Broderip, 1832)

(Figure 4A)

Buccinum muriciforme King & Broderip, 1832: 348.

Xymenopsis muriciformis — Dell, 1972: 38-39, figs 31, 32 (syn-

onymy). Cernohorsky, 1977: 118 (synonymy). Castellanos &

D.G. REID AND C. OSORIO

Landoni, 1993: 16, pl. 3, figs 39, 40. Pastorino & Harasewych,

2000: 43-52, figs 142, 45-49, 83-95, 105-106 (synonymy).

Xymenopsis decolor (Philippi, 1845) — Dell, 1971: 212-213.

Xymenopsis liratus (Gould, 1849) — Powell, 1951: 158-159.

DESCRIPTION. Shell to 26 mm; elongate fusiform, with rounded

whorls; sculptured by 13-15 rounded axial ribs, crossed by regu-

larly spaced incised lines (14-18 on last whorl); apertural lip not

thickened; colour white to purplish grey, interior white to purple.

HABITAT. Dredged from 7—15 m, on bottoms of gravel, or cobbles

on silt with brachiopods. Dell (1971) recorded this species from the

sublittoral to 18 m, and Powell (1951) from 17-170 m off the

Falkland Islands.

RECORDS. Stations 14, 22, 25. According to Dell (1971), from

about 45°S to Tierra del Fuego. Range: 45—54°S.

REMARKS. This genus shows a confusing diversity of shape and

sculpture. Strebel (1904) recognized an improbable 22 species in his

‘Trophon decolor’ group. This genus has recently been revised by

Pastorino & Harasewych (2000).

Xymenopsis subnodosus (Gray, 1839)

(Figure 4B)

Buccinum subnodosa Gray, 1839: 118.

Xymenopsis subnodosus — Pastorino & Harasewych, 2000: 55-56,

figs 96-103, 106.

Fusus cancellinus Philippi, 1845: 67. Philippi, 1846: 117-118,

Fusus pl. 3, fig. 2.

Xymenopsis cancellinus — Powell, 1951: 158.

DESCRIPTION. Shell 23 mm; elongate fusiform with shouldered

whorls; sculptured with rounded axial ribs (10 on last whorl),

crossed by close-set spiral cords, alternately large and small (24 on

last whorl); outer apertural lip thickened and denticulate within;

colour whitish, anterior canal tinged purple.

HABITAT. Single shell dredged from 5—15 m in sheltered bay, on

substrate of cobbles and shells.

RECORDS. Station 1. The type locality of F. cancellinus is the

Magellan Strait (Philippi, 1845). Range: 46-54°S.

REMARKS. Besides the holotype of Philippi’s F. cancellinus, this is

the only specimen known (Pastorino & Harasewych, 2000). The

denticulate lip is unlike other members of the genus.

Family BUCCINIDAE

Pareuthria fuscata (Bruguiére, 1789)

(Figure 4C)

Buccinum fuscatum Bruguiére, 1789: 282.

Pareuthria fuscata — Powell, 1951: 132 (synonymy).

Pareuthria plumbea (Philippi, 1844) — Powell, 1951: 133. Dell,

1971: 207-208 (synonymy). Castellanos, 1992: 13, pl. 3, fig. 37.

Pareuthria magellanica (Philippi, 1848) — Powell, 1951: 133 (syn-

onymy).

DESCRIPTION. Shell to 30 mm; elongate fusiform; spire whorls

sculptured with low, rounded axial ribs, becoming obsolete on last

1-2 whorls, otherwise smooth, but sometimes with indistinct spiral

<_<

MOLLUSCA OF SOUTHERN CHILE

striae; aperture becoming somewhat thickened and lirate within in

largest specimens; colour dark bluish or purplish grey, aperture

purple.

HABITAT. Common inrock pools in Mytilus zone, among holdfasts,

under stones and in shell gravel, on moderately exposed shores; also

under stones on silt, in sheltered tidal pool, just sublittoral. Previous

authors have recorded this species mainly from the lower eulittoral

and shallow subtidal, but occasionally from depths of up to 16 m

(Powell, 1951) or 40 m (Strebel, 1905a). It was found in a survey of

Macrocystis holdfasts in the Beagle Channel (Ojeda & Santelices,

1984).

RECORDS. Stations 5, 12, 14. Elsewhere I. Chiloé to Magellan

Strait and Tierra del Fuego (Strebel, 1905b); Dell (1971) records this

species only as far north as 49°S. Range: 43-55°S.

REMARKS. The development of the axial ribs is variable, some

examples being almost smooth, and both Strebel (1905b) and Powell

(1951) distinguished three species on the basis of shell characters. A

critical revision is required to confirm whether these are but forms of

a single species (Dell, 1971).

Pareuthria powelli Cernohorsky, 1977

(Figure 4D)

Pareuthria rosea (Hombron & Jacquinot, 1854) — Powell, 1951:

133. Dell, 1971: 206-207 (synonymy) (junior primary homonym

of Fusus roseus Anton, 1838).

Pareuthria scalaris (Watson, 1882) — Powell, 1951: 134 (syn-

onymy). Cernohorsky, 1977: 109 (synonymy) (junior primary

homonym of Fusus scalaris Lamarck, 1816).

Pareuthria powelli Cernohorsky, 1977: 109, fig. 5 (synonymy).

DESCRIPTION. Shell to 17 mm; elongate fusiform; sculptured with

rounded axial ribs (9-12 on last whorl), crossed by fine spiral ribs

(about 21 on last whorl) becoming finer and sometimes obsolete

towards suture; apertural lip thin or (in thick-shelled specimens)

slightly thickened and indistinctly denticulate within; colour pinkish

purple or white.

HABITAT. Under stones on silt, in sheltered tidal pool, just

sublittoral; dredged from 7—9 and 10-15 m, on bottom of silt with

pebbles and shells, and on cobbles with encrusting calcareous algae.

Recorded from depths of up to 201 m (Powell, 1951).

RECORDS. Stations 7, 14, 22, 25. Elsewhere from 47°48’S in

northwest Patagonia (Watson, 1886: 203), 49°S to Magellan Strait

(Dell, 1971) and Tierra del Fuego (Strebel, 1905b), so that the

| present records are the most northerly. Range: 46—-55°S.

| REMARKS. The synonymy above follows Cernohorsky (1977). If

| this is correct, this is a variable species in shell thickness, promi-

| nence of sculpture, elongation of spire and colour, but a critical

reappraisal based on more material is necessary. Although some-

| what eroded, the protoconch of the present specimens appears to be

| only about two-thirds of the size of that of shells from the area

between the Falkland Islands and Patagonia.

| Glypteuthria meridionalis (Smith, 1881)

| (Figure 7E)

| Euthria meridionalis E.A. Smith, 1881: 29-30, pl. 4, fig. 6.

Euthria (Glypteuthria) meridionalis — Strebel, 1905b: 627-629, pl.

21, fig 11, 1la—d.

127

Glypteuthria meridionalis — Powell, 1951: 138. Dell, 1972: 36, fig.

10 (synonymy). Castellanos, 1992: 19, pl. 1, fig. 11.

DESCRIPTION. Shell 6.2 mm (to 9 mm, Smith, 1881); narrowly

fusiform; sculptured with rounded axial ribs (14 on last whorl),

crossed by spiral grooves (about 13 on last whorl); apertural lip

slightly thickened and smooth within; colour whitish.

HABITAT. Single specimen dredged from 10 m, on bottom of

cobbles, gravel and shells. To 38 m (Powell, 1951).

RECORDS. Station 14. Elsewhere recorded only to the south from

Portland Bay, St Andrew’s Sound to Magellan Strait (Smith, 1881)

and Tierra del Fuego (Strebel, 1905b). Range: 46-55°S.

Family NASSARIIDAE

Nassarius gayii (Kiener, 1834)

(Figure 4E)

Buccinum gayii Kiener, 1834: 71-72, pl. 21, fig. 79.

Nassarius gayi — Marincovich, 1973: 37, fig. 80. Castellanos, 1992:

23, pl. 2, fig. 18.

Nassarius gayii — Cernohorsky, 1975: 141-143, figs 44-49 (syn-

onymy). Cernohorsky, 1984: 34 (synonymy).

DESCRIPTION. Shell to 14 mm; broadly fusiform; sculptured with

axial ribs, becoming obsolete at end of last whorl, crossed by flat

spiral ribs (10-11 on last whorl), forming low nodules at their

intersections; apertural lip thickened and lirate within; colour pale

brown with dark brown spiral ribs, aperture white with brown

margin.

HABITAT. Among Mytilus holdfasts and on shell gravel, in rock

pools in low eulittoral on moderately exposed shores; more com-

monly dredged from 6—15 m, on bottoms of cobbles encrusted with

calcareous algae, on gravel, and on silt with shell fragments. At

Iquique in northern Chile Marincovich (1973) recorded this species

from the middle and lower intertidal, on the undersides of rocks in

gravel. At Isla Chiloé Brattstro6m (1990) found it commonly in the

lower eulittoral zone.

RECORDS. Stations 1, 5, 7, 11, 12, 14. Elsewhere I. Lobos de

Afuera (Peru) (Marincovich, 1973) to Puerto Rosario and Bahia

Tom (50°S, Smith, 1881) and Magellan Strait (Dall, 1909). The

southern limit is unclear; the species was common around 46°S in

the present study, Smith (1881) recorded seven immature specimens

(as ‘Nassa taeniolata Philippi, 1845’) from 50°S, and Dall (1909)

stated that the species ranged to the Magellan Strait (54°S), yet Dell

(1971) did not record it in extensive collections between 42 and

55°S. Range: 7-54°S.

Family VOLUTIDAE

Adelomelon ancilla (Lightfoot, 1786)

(Figure 4F, M)

Voluta ancilla Lightfoot, 1786: 137.

Adelomelon ancilla — Powell, 1951: 160-163. Castellanos &

Landoni, 1992: 8, pl. 1, fig. 1. Poppe & Goto, 1992: 21, 109-110,

pl. 35 (in part).

Adelomelon (Adelomelon) ancilla — Clench & Turner, 1964: 152-

154, pls 82, 83, 92-94 (synonymy, radula). Weaver & duPont,

128

1970: 102-103, fig. 20a—c, n, pl. 42A—C (synonymy). Osorio,

Atria & Mann, 1979: 19-20, fig. 19.

DESCRIPTION. Shell to 186 mm (Clench & Turner, 1964); large,

fusiform, with long narrow aperture; sculpture usually smooth but

for very fine growth lines, but apical whorls may bear fine spiral

striae and longitudinal ribs; apertural lip smooth, only slightly

thickened, columella with 2—4 sharp folds; colour cream with sparse

longitudinal zigzag brown lines, dark brown when covered by

periostracum, interior pale orange.

HABITAT. O-172 m (Powell, 1951), on sand bottoms to 310 m

(Poppe & Goto, 1992). The single dead shell in the present material

was dredged from 10 m on a gravel bottom.

RECORDS. Station 14. Elsewhere Magellan Strait to Falkland Is-

lands and southern Brasil (Clench & Turner, 1964), I. Chiloé (M.G.

Harasewych, pers. comm.). Range: 42—54°S.

REMARKS. This species is represented in the present collection by

a single dead shell, a small juvenile of 18 mm (Fig. 4F), clearly

assigned to the Volutidae by the large protoconch (with evidence of

a pointed calcarella, see Clench & Turner, 1964: pl. 93) 5.2 mm in

diameter. Identification to species has been based on the relatively

narrow first whorl of the teleoconch (indicating a tall narrow spire)

and on the teleoconch sculpture of spiral striae and slight axial folds.

Many specimens of A. ancilla are smooth at the apex, but this

sculptured form was described by Strebel (1906) as Voluta martensi,

subsequently synonymized by Clench & Turner (1964). An adult

shell of A. ancilla from the Falkland Islands is illustrated in Figure

4M. The taxonomy of this complex of large Magellanic volutes

remains confused. Powell (1951) pointed out the similarity of the

shells of A. ancilla and A. magellanica (Gmelin, 1791) and regarded

them as extremes of a single variable species. However, Clench &

Turner (1964) figured two very different radulae, and on this basis

transferred the latter to the new genus Odontocymbiola, distinct at

subfamilial level. Characters of the shell were not entirely diagnos-

tic, but that of O. magellanica was said to be broader and more solid,

and the protoconch apparently larger. This treatment was followed

by Weaver & duPont (1970). However, in the most recent mono-

graph of the family, Poppe & Goto (1992: 21, 109-110) have

rejected the evidence of the radular differences, and on the basis of

shell characters have synonymized these two, together with A.

paradoxa (Lahille, 1895). Clearly, additional anatomical informa-

tion is required to resolve this problem. The egg capsules are

attached to hard substrates; one illustrated by Strebel (1906: pl. 10,

fig. 52) is domed, 53 mm in diameter and contains seven embryonic

shells up to 14 mm in length; capsule and embryos have also been

figured by Carcelles (1944: pl. 3, figs 35-38).

Family TRITONIIDAE

Tritonia challengeriana Bergh, 1884

Tritonia challengeriana Bergh, 1884: 45-47, pl. 11, figs 16-19, pl.

12, figs 1-8 (anatomy, radula). Schrodl, 1996: 35, pl. 6, fig. 39

(synonymy).

DESCRIPTION. Animal up to 35 mm; oral veil with finger-like

processes; rhinophores with basal sheaths; body approximately

D.G. REID AND C. OSORIO

quadrilateral in cross section, along each lateral angle the mantle

forms a row of 15-21 branched pallial gills; colour white.

HABITAT. Among and beneath stones in pools in lowest eulittoral,

at top of red algal zone, on moderately sheltered shore. Recorded

from depths up to 18 m by Schrédl (1996), and dredged from 315 m

by the Challenger Expedition (Bergh, 1884). Members of this

family mostly feed on alcyonarians (Thompson & Brown, 1984).

RECORDS. Station 14. Elsewhere I. Chiloé to Magellan Strait

(Schroédl, 1996). Range: 42—-54°S.

Family FLABELLINIDAE

Flabellina falklandica (Eliot, 1907)

Coryphella falklandica Eliot, 1907: 354, pl. 28, fig. 7 (radula).

Flabellina falklandica — Schrédl, 1996: 37, pl. 7, fig. 44 (syn-

onymy).

DESCRIPTION. Animal up to 10 mm (to 40 mm, Schrédl, 1996);

rhinophores smooth; rhinophores and oral tentacles of similar size;

propodial tentacles present; dorsally with dense cerata, not arranged

in groups; colour transparent whitish with orange brown cerata.

HABITAT. On Macrocystis (as also noted by Schrédl, 1996) at 5—15

m depth, where the animals presumably graze on epiphytic hydroids.

RECORDS. Stations 1, 14. Elsewhere Seno Reloncavi to Magellan

Strait (Schrédl, 1996, 1997). Range: 42—-54°S.

Family SIPHONARITDAE

Siphonaria (Talisiphon) lessonii Blainville, 1827

(Figure 4G, H)

Siphonaria lessonii Blainville, 1827: 296, pl. 61, fig. 2, 2a.

Siphonaria (Pachysiphonaria) lessoni — Hubendick, 1946: 21-22,

fig. 4, pl. 1, figs 1-3 (anatomy). Olivier & Penchaszadeh, 1968:

469-491, pl. 1, textfigs. 2, 3, 5 (radula, anatomy). Dell, 1971:

214-215 (synonymy).

Pachysiphonaria lessoni — Powell, 1951: 181.

Siphonaria (Talisiphon) lessoni — Morrison, 1963: 7 (synonymy).

Marincovich, 1973: 42, fig. 95.

Siphonaria tristensis Leach, 1824 — Strebel, 1907: 170-172, pl. 3,

figs 31-33.

DESCRIPTION. Shell to 20 mm; high (rarely low) conical to cap-

shaped limpet, apex at about one third shell length from posterior

margin, posterior slope sometimes concave, basal outline asym-

metrically oval, with slight projection on right side (corresponding

to pneumostome opening of animal); sculpture smooth or with slight

radial ribs; colour pale with numerous fine dark brown to black

radial lines, interior dark brown with pale margin where exterior

dark rays show through.

HABITAT. Abundant on rocks on sheltered and exposed shores; in

upper eulittoral together with barnacles and Nodilittorina araucana,

extending into zones of Nacella and Mytilus, and often attached to

Fig.4 A. Xymenopsis muriciformis (20 mm). B. Xymenopsis subnodosus (23 mm). C. Pareuthria fuscata (30 mm). D. Pareuthria powelli (17 mm). E.

Nassarius gayii (12 mm). F. Adelomelon ancilla (juvenile; 18 mm). G, H. Siphonaria (Talisiphon) lessonii (15 mm). I. Chilina patagonica (15 mm). J, K.

Malletia magellanica (19 mm, 14 mm). L. Mulinia edulis (60 mm). M. Adelomelon ancilla (adult; 200 mm; Falkland Islands). N. Felaniella inconspicua

(18 mm). O. Zygochlamys patagonica (juvenile;17 mm). (All specimens from study area except M; all NHM collection).

eas

cal

aa)

—

ie)

22)

fe)

130

these shells; on sheltered shores it is common even on silty rock

surfaces; found at seawater salinities down to 20%o, but also frequent

at mouths of streams where salinity must fall to very low levels at low

tide or during rain. In northern Chile it is reported to be common in the

barnacle zone and also in tidepools throughout the eulittoral (Guiler,

1959a; Marincovich, 1973), and is also common over a wide tidal

range in the Magellan Strait (Benedetti-Cecchi & Cinelli, 1997).

Together with lottiid limpets of the genus Scurria, Siphonaria lessonii

is one of the most abundant herbivores of the mid-intertidal zone of

southern Chile, reaching densities of 1317 per m* and grazing

principally on Jridaea fronds (Jara & Moreno, 1984). In a marine

reserve this species occured mainly in the mid and upper eulittoral;

outside the reserve, where the competing dominant herbivore

Fissurella picta is removed by human collection, S. lessonii was

larger and extended its zonation to low tide level (Godoy & Moreno,

1989). A detailed study of the ecology of this species has been made

in the Mar del Plata, Argentina (Olivier & Penchaszadeh, 1968).

RECORDS. Stations 1, 6, 8, 10, 11, 12, 14, 20, 21, 25. Elsewhere

Paita (Peru) to Magellan Strait and Tierra del Fuego (Hubendick,

1946; Marincovich, 1973). Range: 5—54°S.

REMARKS. This is one of the most abundant molluscs in the upper

intertidal zone in the study area. It is a pulmonate limpet, recognized

by the pneumostome of the mantle to the right side of the foot. It

should not be confused with Scurria parasitica which is a symmetri-

cally oval limpet, with broader dark rays, and white interior with

brown apex; these two limpets frequently occur together in beds of

Mytilus.

Family CHILINIDAE

Chilina patagonica Sowerby, 1874

(Figure 41)

Chilina patagonica Sowerby, 1874: Chilina sp. 11, pl. 3, fig. 11.

Strebel, 1907: 166-168, pl. 8, figs 98, 102, 105a—c. Haeckel,

1911: 89-136, pls 7-11 (anatomy). Stuardo, 1961: 22 (synonymy).

Castellanos & Gaillard, 1981: 34, pl. 5, figs 15, 16 (synonymy).

DESCRIPTION. Shell to 16 mm; cylindrical with produced spire,

apex usually eroded away; shell thin and covered by thick

periostracum; columella with one prominent fold; colour yellow

brown with more or less distinct axial lines of dark brown which

form four conspicuous spiral bands of chevrons or irregular axial

marks, columella white.

HABITAT. Common among stones, Enteromorpha and on mud, in

sheltered brackish inlet (salinity 5%oc) near freshwater stream, also

among saltmarsh vegetation on sheltered shores of Laguna San

Rafael. Strebel (1907) recorded this species from marine fjords, and

Davenport et al. (1995) found it commonly in streams and saltmarsh

vegetation in the Laguna San Rafael. In Estero Reloncavi Bratt-

str6m (1990) recorded Chilina bulloides Sowerby from similar

low-salinity habitats.

RECORDS. Stations 28, 31. Elsewhere Puerto Montt to I. Picton

(Strebel, 1907). Range: 41—-55°S.

REMARKS. There are about 36 nominal species of Chilina recorded

from Chile (Stuardo, 1961; Ituarte, 1997), mostly from freshwater

habitats. Shells are variable in form and coloration, making identifi-

cation difficult. A review of the Chilean species based on anatomical

and radular characters is in progress (Valdovinos & Stuardo, 1995).

Meanwhile, the identification of the present material has been based

D.G. REID AND C. OSORIO

on comparison with dry syntypes (NHM) and on the interpretations

of Strebel (1907) and Castellanos & Gaillard (1981). There are

several anatomical accounts of Chilina species (Haeckel, 1911;

Brace, 1983; Ituarte, 1997) and they are of evolutionary interest as

primitive basommatophoran pulmonates.

Class Bivalvia

Family NUCULIDAE

Nucula (Nucula) pisum Sowerby, 1833

(Figure 7G)

Nucula pisum Sowerby, 1833a (January): 6, pl. 3, fig. 23. Sowerby,

in Broderip & Sowerby, 1833 (March): 198. Dall, 1909: 250.

Soot-Ryen, 1959: 12, pl. 1, figs 1, 2.

Linucula pisum — Dell, 1964: 144, pl. 2, figs 7, 8 (synonymy).

Ramorino, 1968: 183-185, pl. 1, fig. 4, pl. 4, fig. 2. Osorio &

Bahamonde, 1970: 187. Maxwell, 1988: 89.

Nucula (Linucula) pisum — Bernard, 1983: 10 (synonymy).

Nucula (Nucula) pisum — Villarroel & Stuardo, 1998: 129-131.

DESCRIPTION. Shell to 3.3 mm (to 5.4 mm, NHM); rounded

trigonal; hinge taxodont, 9-14 anterior teeth, 5 posterior (Soot-

Ryen, 1959); sculpture of strong concentric striae towards margin in

larger shells, crossed by apparent radial lines throughout (these are

subsurface prisms within outer shell layer) that crenulate the margin,

radials on escutcheon are finer and divergent from the rest; colour

fawn, stained by ferruginous deposit at umbos, interior nacreous.

HABITAT. Dredged from 10-15 m depth, among cobbles with

encrusting calcareous red algae. Recorded from depths of 5-60 m on

coarse or fine sand by Soot-Ryen (1959). Villarroel & Stuardo

(1998) reported a maximum density of 848 per m? on sandy mud at

51-80 m in the Bahia de Valparaiso, and gave an overall depth range

of 8-200 m; from the same locality Ramorino (1968) recorded

densities of up to 4650 per m?.

RECORDS. Station 7 (2 specimens). Elsewhere, the extent of the

range is uncertain. Soot-Ryen (1959) gave Valparaiso (the type

locality) and recorded specimens from 41—43°S. Dall (1909) gave

‘Valparaiso to San Blas, Chile’ (the latter presumably Estrecho San

Blas, 51°S, but mis-quoted as San Blas, Argentina, a locality at

40°S, by Carcelles & Williamson, 1951, Soot-Ryen, 1959, and

Osorio & Bahamonde, 1970). Carcelles & Williamson (1951) also

included the Magellanic region and Falkland Islands. However, Dell

(1964) noted possible confusion with Nucula falklandica Preston,

1912, in these southern parts of the range. Range: 25—54°S.

REMARKS. Maxwell (1988) and Villarroel & Stuardo (1998) have

discussed the generic allocation of this species.

Family MALLETIIDAE

Malletia magellanica (Smith, 1875)

(Figure 4J, K)

Solenella magellanica Smith, 1875: 118-119.

Malletia magellanica — Smith, 1881: 39, pl. 5, fig. 3, 3a. Carcelles,

1950: 74, pl. 3, fig. 65. Carcelles & Williamson, 1952: 324.

Osorio & Bahamonde, 1970: 188. Villarroel & Stuardo, 1998:

155-156.

MOLLUSCA OF SOUTHERN CHILE

DESCRIPTION. Shell to 31 mm (38 mm, Smith, 1881); ovate, more

or less pointed posteriorly, delicate; surface smooth, with growth

lines; periostracum thick, glossy; external ligament; hinge taxodont,

8-9 anterior teeth, 17—20 posterior teeth (but sometimes distorted

when umbos are eroded); pallial sinus large, but distant from pallial

line, so that meeting of the two is bluntly rounded; colour yellow

brown to dark or olivaceous brown, interior white.

HABITAT. Dredged from 5-15 m depth on silt bottom, abundant in

Laguna San Rafael at salinity of 15%. Smith (1881) recorded this

species from 4-58 m depth on mud in the northwestern Magellan

Strait.

RECORDS. Stations 25, 29, 30. Elsewhere Islas Otter (52°S) and

Caleta Cockle (Smith, 1881). Carcelles & Williamson (1951) give

the Magellanic region and Kerguelen Islands. Range: 46—52°S.

REMARKS. Six nominal species of Malletia are recorded from

southern Chile (Osorio & Bahamonde, 1970), and the chief distin-

guishing features are shell outline, numbers of hinge teeth and the

form of the pallial sinus (Soot-Ryen 1959; Dell, 1964; Ramorino,

1968; Villaroel & Stuardo, 1998). Both the hinge and pallial line of

the present specimens are identical to those of the syntypes in the

NHM, but the largest syntype (and the figures of Smith, 1881, and

Carcelles, 1950) shows a markedly more rostrate posterior. How-

ever, two of the three syntypes are less rostrate, and overlap with the

most elongate examples of the present collections (e.g. Fig. 4K).

Dell (1964) has observed variation in the development of the

rostrum in another Malletia species. The majority of the samples

from the Laguna San Rafael are, nevertheless, more oval in outline,

and additional material is necessary to confirm our identification.

Family MYTILIDAE

Mytilus edulis chilensis Hupé, 1854

(Figure 5D, E)

Mytilus chilensis Hupé, 1854: 309-310, malacologia pl. 5, fig. 4.

Reid, 1974: 179-184. Osorio, Atria & Mann, 1979: 25-26, fig. 27.

Mytilus edulis chilensis —Soot-Ryen, 1959: 24-25. Dell, 1964: 174.

Osorio & Bahamonde, 1970: 191. Dell, 1971: 170-171.

Mytilus edulis Linnaeus, 1758 — Soot-Ryen, 1955: 19-22, pl. 1, figs

1, 2, textfigs 1, 2, 10, 11 (anatomy, synonymy). Olsson, 1961:

113, pl. 12, fig. 6. McDonald, Seed & Koehn, 1991: 323-333.

DESCRIPTION. Shell to 105 mm; beaks terminal, pointed; shell

solid, but thinner and translucent in brackish habitats (Fig. 5D); 3-

4 small tooth-like folds within umbos; chalky resilial ridge adjacent

to ligament pitted by minute pores; posterior adductor and retractor

scars continuous; radial sculpture absent; periostracum thick, glossy,

with hairs in very small specimens; colour blue or sometimes pale

brown, overlaid by black or brown periostracum, eroded at umbos;

interior nacreous, silvery blue.

HABITAT. An abundant species in a wide range of intertidal habi-

tats; on exposed shores it forms dense beds from the middle to lower

eulittoral on rocks and cliffs (size increases towards lower levels and

in more sheltered situations); on sheltered shores it occurs also

among stones and boulders; in estuaries and lagoons it forms clumps

on hard substrates in muddy situations, occurring adjacent to fresh-

water streams; in a brackish inlet (station 28) the species was still

common on the muddy shore at a salinity of 5%c; in the Laguna San

Rafael it occurred intertidally and was also dredged from 5S—10 m, in

clumps on mud and gravel, at salinities of 15%o. Mytilus edulis

131

chilensis is an important component of the ecosystem of the Laguna,

where its occurrence and zonation have been described by Daven-

port et al. (1995). Soot-Ryen (1959) notes that although the species

is mainly intertidal, a few living specimens have been found at 25 m

depth. Ecological studies of this species include those by Miranda &

Acuna (1979) in the Magellan Strait and by Stotz (1981) in an

estuary near Valdivia.

RECORDS. Stations 5, 6, 10, 12, 13, 14, 15, 17, 20, 21, 22, 24, 25,

26, 28, 29, 30, 31. Elsewhere, Soot-Ryen (1959) reports specimens

from Iquique to Magellan Strait. The species is evidently scarce in

central and northern Chile, for it is not reported in ecological or

faunistic studies of this region (Marincovich, 1973; Romo & Alveal,

1977; Ruiz & Giampaoli, 1981). Range: 20-54°S.

REMARKS. Mytilus edulis has a wide, bipolar distribution in the

north Atlantic and southern South America. Traditional morpho-

logical comparison of shells has failed to detect consistent differences

between the northern and southern groups (Soot-Ryen, 1955),

although they have often been recognized as distinct subspecies on

account of their geographical separation (Soot-Ryen, 1959). More

recently, multivariate morphometric analysis has shown that South

American mussels are intermediate in shell shape between the

northern M. edulis and M. trossulus Gould, 1850, but since allozyme

analysis has revealed a closer similarity to northern M. edulis, this

name has been tentatively applied to the southern forms also

(McDonald etal., 1991). Reid (1974) described the digestive system

and claimed that Chilean material differed from a published account

of northern M. edulis, but this requires confirmation. The presence

of this species in South America is apparently not the result of recent

human introduction from the north Atlantic, since there are some

genetic differences and, furthermore, the species is present in pre-

Colombian shell middens in Argentina (McDonald et al., 1991). The

modern information on classification and evolution of Mytilus has

been reviewed by Gosling (1992) and Seed (1992). Until the geo-

graphical relationships of M. edulis are resolved, we retain subspecific

distinction for the Chilean form. Well preserved specimens of M.

edulis chilensis have a smooth surface, but care must be taken to

distinguish eroded specimens from the longitudinally ribbed

Aulacomya atra and Perumytilus purpuratus, with which they may

occur on the same shore. Choromytilus chorus is externally similar

to M. edulis chilensis, but reaches much larger size and is mainly

found subtidally. Another large mytilid, Perna perna (Linnaeus,

1758), has been recorded from Concepcion to the Magellan Strait

(Carcelles & Williamson, 1952, as Chloromya achatinus; see Soot-

Ryen,1955: 30); this is similar in shape to M. edulis chilensis, or

slightly more elongate, externally brown or green, internally purp-

lish or pink, with a wide separation between the posterior adductor

and retractor scars. Mytilus edulis chilensis is an important edible

species, of which the annual harvest was 13358 tonnes in 1997

(SERNAP, 1998) and is also cultivated commercially.

Choromytilus chorus (Molina, 1782)

(Figure 5F)

Mytulus chorus Molina, 1782: 202.

Choromytilus chorus — Soot-Ryen, 1955: 31, pl. 2, figs 7, 8, textfig.

5 (synonymy). Soot-Ryen, 1959: 26. Olsson, 1961: 115, pl. 12,

fig. 10. Osorio & Bahamonde, 1970: 191. Osorio, Atria & Mann,

1979: 24-25, fig. 26. Bernard, 1983: 18 (synonymy).

DESCRIPTION. Shell to 186 mm (to 300 mm, Suchanek, 1985);

beaks terminal, pointed; shell solid; single tooth-like fold within

umbo of right valve, and corresponding groove in left valve; resilial

132

ridge adjacent to ligament not pitted by pores; posterior adductor

and retractor scars continuous; radial sculpture absent; periostracum

very thick, glossy; colour blue to purple, overlaid by black

periostracum, often eroded at umbos; interior nacreous, silvery blue.

HABITAT. No living specimens were found during the present

study. Elsewhere, this mussel has been recorded in a variety of

habitats; on the exposed rocky coasts of southern Chile it occurs in

the sublittoral, and also in the low eulittoral in the absence of

collection by humans (Moreno, 1995); it is also frequent in estuar-

ies, sometimes on sedimentary substrates, and at reduced salinities

(monthly average high tide salinity of 20%c, Navarro, 1988). A

depth range of 4-20 m was given in a study of growth and reproduc-

tion by Lozada, Rolleri & Yanez (1971).

RECORDS. Stations 9 (midden material), 10 (fresh valves). Else-

where Pacasmayo (Peru) to Tierra del Fuego (Soot-Ryen, 1955).

Range: 7—-56°S.

REMARKS. Superficially similar in shape to the smaller Mytilus

edulis chilensis, this species is distinguished by its single hinge tooth

and resilial ridge without pits. It is the largest and most esteemed of

the edible mussels of the Chilean coast, and consequently is exten-

sively collected; in 1997 the catch was 527 tonnes. Despite a

considerable literature on the culture and laboratory behaviour of

this species, there is little information about its natural ecology. At

present, populations are almost entirely sublittoral throughout the

region, although where shores are protected from human activity

large numbers appear in the lower eulittoral (Moreno, 1995). This

mussel is a major component of the large shell middens on Isla

Traiguén; the age of these deposits is not known, but intact shells

occurred at depths of up to 5 m in the eroding face of the midden at

Station 9. In addition, fresh shells were found at Station 10, presum-

ably recently discarded by fishermen. The species was an important

item of food for the indigenous people of the Chonos Archipelago,

who collected it by diving, and it is possible that the present

restricted distribution is a consequence of exploitation over a long

period of time (P.J. Curry, pers. comm.). In the north of Chile the

species is likewise common in middens, but is now locally extinct,

although whether this is a result of human activity is unclear

(Viviani, 1979).

Aulacomya atra (Molina, 1782)

(Figure 5A, B)

Mytulus ater Molina, 1782: 202-203.

Aulacomya ater — Soot-Ryen, 1955: 33-34, pl. 1, fig. 6, textfigs 17,

18 (synonymy). Soot-Ryen, 1959: 26-27. Olsson, 1961: 116, pl.

14, fig. 9 (synonymy). Osorio & Bahamonde, 1970: 192.

Marincovich, 1973: 8, fig. 3. Osorio, Atria & Mann, 1979: 22-24,

fig. 24. Bernard, 1983: 17-18 (synonymy).

Aulacomya ater ater — Dell, 1964: 175-177 (synonymy). Dell,

WOW ie AL.

Aulacomya atra — Cazzaniga, 1994: 110.

DESCRIPTION. Shell to 154 mm (to 200 mm, Suchanek, 1985);

beaks terminal, pointed; shell solid; single broad tooth-like fold

within umbo of left valve, and corresponding groove in right valve;

D.G. REID AND C. OSORIO

resilial ridge adjacent to ligament not pitted by pores; posterior

adductor and retractor scars broadly continuous; strong radial ribs

present; periostracum thick, glossy; shells less than 40 mm white,

overlaid by yellow to brown periostracum; larger shells purple to

dark blue, overlaid by black periostracum, eroded at umbos; interior

nacreous, silvery to purple.

HABITAT. Adults of this species were only found commonly on

the shore at two relatively inaccessible sites on an exposed rocky

shore and a cliff (Stations 13, 17), where they formed dense clumps

at the top of the calcareous red algal zone in the sublittoral fringe.

Elsewhere, juveniles (to 40 mm) were found in small numbers

among the byssus of dense beds of Mytilus edulis chilensis, and

under stones in the mid to lower eulittoral on moderately exposed

and sheltered shores, but these individuals evidently died before

reaching large size. On the sheltered shores of the southernmost

Estero Elefantes and Golfo Elefantes, adults were occasionally

found on the shore; some were freshly dead, with the byssus

detached from the substrate, whereas others were only superficially

attached; empty valves were common on the beaches in this region.

It appears therefore that there may be considerable sublittoral

populations in this area, from which living and dead mussels are

washed up on the shore. The presence of beds of Macrocystis near

the shore made dredging here difficult, but a living adult was

dredged from 7—9 m (station 22), and a few others were brought up

in the holdfasts of the kelp from 5—15 m. Salinities of 15—20%o

were recorded at the southern sites. Elsewhere, occasional living

specimens have been recorded from 40 m at I. Chiloé (Soot-Ryen,

1959) and from 79 m in the Falkland Islands (Dell, 1964). It was

common in the lower intertidal and subtidal at Iquique

(Marincovich, 1973) and found in the mid to lower intertidal at Isla

Chiloé (Brattstrém, 1990). This species does occur also in more

sheltered situations, as in the Estero Castro, where a natural mussel

bank was studied between depths of 4-9 m, but accumulation of

mud caused mortality (Lozada, 1968).

RECORDS. Stations 1, 5, 13, 14, 17, 20, 22, 25. Elsewhere Callao

(Peru) to Magellan Strait (Soot-Ryen, 1955). Range: 12-56°S.

REMARKS. Although almost universally referred to as Aulacomya

ater in the recent literature, the name should be corrected to A. atra

since, as pointed out by Cazzaniga (1994), the adjectival specific

name should agree in gender with the feminine generic name. This

species is easily distinguished from all other large mussels in the

region by its radially ribbed shell; specimens less than 40 mm in

length could be confused with Perumytilus purpuratus, but at this

size the shells are yellow to pale brown, with less than 17 ribs,

whereas those of P. purpuratus are purplish with a brown to black

periostracum and have twice as many ribs and a more rounded

outline. Like the preceding species, A. atra is a large mussel that is

collected commercially in large quantities; the catch in 1997 was

6597 tonnes (SERNAP, 1998). It is unclear to what extent the

present scarcity of intertidal populations is a result of

over-exploitation. This species is the major component of the large

shell middens on Isla Traiguén; these are of unknown age, but some

are up to 5 m in height. Fresh valves at some sites suggests that

collection continues.

Fig.5 A, B. Aulacomya atra (juvenile 26 mm; adult 80°mm). C. Perumytilus purpuratus (39 mm). D. Mytilus edulis chilensis (thin-shelled form from low

salinity habitat, station 29; 45 mm). E. Mytilus edulis chilensis (thick-shelled form from higher salinity habitat, station 22; 71 mm). EF. Choromytilus

chorus (186 mm). G. Cumingia mutica (25 mm). H. Tawera gayi (18 mm; Portland Bay and Port Rosario, Patagonia, ‘Alert’ Expedition, NHM

1879.10.15.60). I. Venus antiqua (67 mm). J. Retrotapes exalbidus (86 mm). K. Tagelus (Tagelus) dombeii (82 mm). L. Hiatella solida (11 mm). M.

Ensis macha (129 mm; Punta Arenas, Magellan Strait, NHM 1868.7.1.22). N—P. Bankia (Bankia) martensi (N, shell 7.2 mm; O, pallet 30 mm; P, whole

animal, length 50 mm approx.). (All specimens from study area except H and M; all NHM collection).

MOLLUSCA OF SOUTHERN CHILE

134

Perumytilus purpuratus (Lamarck, 1819)

(Figure SC)

Modiola purpurata Lamarck, 1819: 113.

Brachidontes purpuratus — Soot-Ryen, 1955: 45, pl. 4, fig. 18,

textfig. 30. Soot-Ryen, 1959: 28. Dell, 1971: 172. Bernard, 1983:

18 (synonymy).

Perumytilus purpuratus — Olsson, 1961: 117, pl. 12, fig. 1, pl. 14,

fig. 1, la, 1b (synonymy). Osorio & Bahamonde, 1970: 192.

Marincovich, 1973: 9, fig. 6. Osorio, Atria & Mann, 1979: 24, fig.

DS.

DESCRIPTION. Shell to 50 mm; beaks almost terminal, rounded;

shell solid; several small tooth-like crenulations within umbo; resilial

ridge adjacent to ligament not pitted by pores; posterior adductor

and retractor scars continuous; fine radial ribs present, crenulating

margin; periostracum thick, glossy; shell white, purplish posteriorly,

overlaid by dark brown to black periostracum, eroded at umbos,

interior nacreous, silvery to purplish brown.

HABITAT. Frequent inarange of intertidal habitats: under stones in

mid to upper eulittoral on sheltered boulder shores, forming partly

buried accretions on upper shore of muddy shingle beaches, and

sometimes together with Mytilus edulis chilensis in dense beds of

small shells at top of Mytilus zone in mid-eulittoral on exposed

rocky coasts. The species is especially abundant in sheltered habitats

where there is a moderate freshwater input from streams or runoff,

and was found at salinities down to 15—20%o. This is a strictly

intertidal species (Soot-Ryen, 1959; Dell, 1971), but can be found

throughout the intertidal zone in both southern and northern parts of

its distribution (Marincovich, 1973; Brattstr6m, 1990; Benedetti-

Cecchi & Cinelli, 1997). In central and northern Chile P. purpuratus

is the dominant organism in the mid-eulittoral on both sheltered and

exposed shores, forming dense beds (Guiler, 1959a; Romo & Alveal,

1977; Ruiz & Giampaoli, 1981; Santelices, 1991; Alvarado &

Castilla, 1996). The great abundance of this species may be a

consequence of the removal of its major predator, the edible

Concholepas concholepas, by humans (Castilla & Duran, 1985).

RECORDS. Stations 1, 5, 6, 10, 11, 12, 14, 17, 20, 21, 22, 25, 26.

Elsewhere Yasila near Paita (Peru) (Olsson, 1961) to Magellan Strait

(Soot-Ryen, 1955; Benedetti-Cecchi & Cinelli, 1997). Range: 5—

54°S.

REMARKS. Discrimination from the only other ribbed mussel,

Aulacomya atra, has been described earlier. Perumytilus purpuratus

is seldom found in pure colonies, but almost always together with

Mytilus edulis chilensis. When shells are well preserved, the two are

easily separated by the fine radial ribs of the former. When shells are

severely eroded (as is often the case in habitats of low salinity), the

crenulated margin and purplish shell of P. purpuratus differentiate it

from the blue, smooth-margined shells of M. edulis chilensis. The

proportions of these two species in the mytilid zone appear to vary

with exposure, tidal level and salinity. On exposed shores and at

lower levels P. purpuratus is replaced by M. edulis chilensis.

Perumytilus purpuratus becomes more frequent on sheltered shores,

and wherever there is limited freshwater inflow. However, in estua-

rine areas of the lowest salinity (S—15%c, stations 28, 29, 30, 31) it is

absent and here the presumably more euryhaline M. edulis chilensis

occurs alone.

D.G. REID AND C. OSORIO

Family PECTINIDAE

Zygochlamys patagonica (King & Broderip, 1832)

(Figure 40)

Pecten patagonicus King & Broderip, 1832: 337.

Chlamys patagonica — Soot-Ryen, 1959: 29. Osorio, Atria & Mann,

1979: 28, fig. 30. Waloszek, 1984: 207-276, pls 1-3, pls 5-9

(synonymy).

Chlamys patagonica patagonica — Beu, 1985b:1—11, pl. 1, figs 1-4.

Chlamys (Zygochlamys) patagonica — Dell, 1964: 178-179. Osorio

& Bahamonde, 1970:193.

Zygochlamys patagonica — Waller, 1991: 28-30, pl. 2, figs 13, 14.

Chlamys patriae Doello Jurado, 1918 — Soot-Ryen, 1959: 29-31.

Osorio & Bahamonde, 1970: 193.

Chlamys amandi Hertlein, 1935 — Soot-Ryen, 1959: 29-31, pl. 1,

figs 7, 8. Osorio & Bahamonde, 1970: 193.

DESCRIPTION. Shell 16 mm (to 90 mm, Waloszek, 1984); a round,

almost equivalved scallop; sculptured by 30-32 (22-41, Waloszek,

1984) primary radial ribs (excluding ears), with secondary ribs

between, crossed by fine concentric laminae which may form

minute scales on ribs or in interspaces; right (lower) valve pink,

orange or brown, with darker ribs; left valve white with pink to

orange ribs; interior white, flushed with pink or purple.

HABITAT. Single small specimen dredged from 10-15 m, among

cobbles with encrusting calcareous red algae, in sheltered bay.

Although occasionally taken in the shallow sublittoral, the typical

habitat of this species is in deeper water, 25—100 m in the vicinity of

I. Chiloé (Soot-Ryen, 1959), 15 to over 200 m off eastern Patagonia

and the Falkland Islands (Dell, 1964; Waloszek & Waloszek, 1986).

RECORDS. Station 7. Elsewhere I. Chiloé to Magellan Strait, Tierra

del- Fuego and Cape Horn (Waloszek, 1984). Range: 42—56°S.

REMARKS. A detailed taxonomic study of this and other Magellanic

scallops has revealed that the three species discriminated by Soot-

Ryen (1959) are extremes of the range of a single taxon with variable

microsculpture (Waloszek, 1984). The generic assignment has been

discussed by Beu (1985b) and Waller (1991). This species is fished

commercially in the Magellan Strait (Osorio et al., 1979) and in

1997 the catch was 2598 tonnes (SERNAP, 1998). During the

present study fossil specimens of an additional pectinid species,

Chlamys vitrea (King & Broderip, 1832), were found in a clay cliff

of an eroding raised beach on the southwestern shore of Isla Rojas.

This species has a more delicate shell, transparent when young, with

less distinct, rounded ribs and in life is associated with Macrocystis

(Waloszek, 1984: pl. 4, fig. 5).

Family UNGULINIDAE

Felaniella inconspicua (Philippi, 1845)

(Figure 4N)

Diplodonta inconspicua Philippi, 1845: 53. Hupé, 1854: 357,

malacologia pl. 8, fig. 4. Soot-Ryen, 1959: 43 (synonymy). Herm,

1969: 115, pl. 3, figs 5—7. Osorio & Bahamonde, 1970: 199. Dell,

eile N73.

Fig.6 Scanning electron micrographs of Polyplacophora. A, C. Leptochiton (Leptochiton) medinae (C, detail of girdle spicules). B, D. Ischnochiton

(Ischnochiton) stramineus (D, detail of girdle scales). E. Ischnochiton (Haploplax) pusio, detail of girdle scales. F. Chiton (Amaurochiton) magnificus

bowenii, detail of girdle scales. (All specimens from study area; NHM collection).

MOLLUSCA OF SOUTHERN CHILE

cs vi i)

VAG G5 BY Bed { ae :

4 45 /

dtd

135

136

? Diplodonta phillippii Hupé, 1854: 357-358, malacologia pl. 8, fig.

Felaniella inconspicua — Bernard, 1983: 30.

DESCRIPTION. Shell 19 mm (to 32 mm, Soot-Ryen, 1959); orbicu-

lar, thin-shelled, only moderately inflated; sculpture of fine concentric

growth lines; the larger of two cardinal teeth in each valve bifid;

pallial line entire, not indented, adductor muscle scars almost equal;

colour white.

HABITAT. Dead valves dredged from 10—15 m depth, on bottoms

of gravel, coarse sand and cobbles; scarce. This species has been

recorded intertidally in sand, and living to depths of 36 m (Soot-

Ryen, 1959) and 65 m (Ramorino, 1968).

RECORDS. Stations 7, 14. Elsewhere Tocopilla to Golfo Corcovado

(Soot-Ryen, 1959). Range: 22—-49°S.

REMARKS. ‘The four valves in the present material are more deli-

cate and less inflated than typical shells of F: inconspicua. In this

they correspond with the description of Diplodonta phillippii from

Isla Chiloé by Hupé (1854); although this was regarded only as a

form of D. inconspicua by Soot-Ryen (1959), the status of the two

taxa deserves further investigation.

Family GALEOMMATIDAE

Lasaea miliaris (Philippi, 1845)

(Figure 7H, I)

Kellia miliaris Philippi, 1845: 51.

Lasaea miliaris — Soot-Ryen, 1959: 51. Dell, 1971: 174-175, pl. 1,

fig. 9, pl. 2, figs 3, 4. Castellanos, 1979: 136.

DESCRIPTION. Shell to 2.8 mm; orbicular, inflated, umbos promi-

nent; sculpture of very fine, regular growth lines; colour pink to

purplish red.

HABITAT. In empty barnacles in barnacle zone of upper eulittoral,

on exposed and moderately exposed shores. At Isla Chiloé a similar

(possibly identical) form, identified as L. petitiana Recluz, was

abundant in the barnacle zone (Brattstrom, 1990).

RECORDS. Stations 12, 14. Elsewhere Magellan Strait, Tierra del

Fuego, Falkland Is (Soot-Ryen, 1959; Dell, 1971). Range: 46—-56°S.

REMARKS. Members of this genus are common components of

the crevice fauna on rocky shores throughout the world. The

taxonomy of this genus of minute bivalves was unsatisfactory

when based only on rather variable shell features (Dell, 1971).

However, it has now been thrown into further confusion by the

discovery that most of the ‘species’ are highly polyploid asexual

lineages, with nonplanktotrophic, brooded development (O Foighil

& Smith, 1995). The present material has been compared with

syntypes in NHM, but the specific name is used only in the sense

of a morphospecies.

Family CARDITIDAE

Carditella tegulata (Reeve, 1843)

(Figure 7J)

Cardita tegulata Reeve, 1843: sp. 48, pl. 9, fig. 48. Reeve, 1844:

194.

Carditella tegulata — Lamy, 1922: 354-355, textfig. Carcelles &

D.G. REID AND C. OSORIO

Williamson, 1951: 334. Dell, 1964: 194, textfig. 3, no. 8 (syn-

onymy). Osorio & Bahamonde, 1970: 197. Bernard, 1983: 34.

DESCRIPTION. Shell to 7.5 mm; subtrigonal, solid; sculptured by

11-13 strong radial ribs, crossed by fine regular concentric ribs,

producing lamellate appearance on radials; margin coarsely

crenulated by radial ribs; small external ligament; colour whitish

with yellow brown periostracum.

HABITAT. Dredged from 10 m on bottom of cobbles, gravel and

coarse sand; uncommon. From 50 m at Valparaiso (Reeve, 1843).

RECORDS. Station 14 (5 specimens). Elsewhere Callao (Peru) to

Magellan Strait (Carcelles & Williamson, 1951). Range: 12-54°S.

REMARKS. This species is closely similar to Carditella pallida

Smith, 1881. Smith (1881) distinguished his species by the 14-15

ribs and almost centrally placed umbos, and these characters are

confirmed by our examination of the two syntypes (NHM, type

locality Valparaiso). In comparison, the three syntypes of C. tegulata

(NHM, type locality Port Rosario, south Patagonia) have 11-12

coarser ribs and slightly more anterior umbones. However, these

differences are slight. The four specimens in the present material

resemble C. tegulata in sculpture, but the ribs are slightly less

pronounced, 11—13 in number, and the shell outline is closer to that

of C. pallida. Our specimens are therefore intermediate in form, as

well as in locality, between these two taxa and suggest possible

clinal variation between them. Dell (1964) emphasized the close

relationship of this pair of species; further investigation is desirable.

Care must be taken to distinguish this species from Carditopsis

flabellum, with which it occurs. Our familial assignment of both

these species follows Chavan (1969). The specimens figured by

Soot-Ryen (1959: pl. 1, fig. 11) and Marincovich (1973: fig. 9) are

not C. tegulata, but belong to the C. naviformis (Reeve, 1843) group,

with more oblong shells (see Dell, 1964).

Family CONDYLOCARDITDAE

Carditopsis flabellum flabellum (Reeve, 1843)

(Figure 7K)

Cardita flabellum Reeve, 1843: sp. 47, pl. 9, fig. 47. Reeve, 1844:

194.

Carditopsis flabellum — Lamy, 1922: 360. Soot-Ryen, 1959: 40.

Ramorino, 1968: 204-206, pl. 2, fig. 2, pl. 6, figs 2, 3. Bernard,

1983: 35.

Carditopsis flabellum flabellum — Dell, 1964: 195, textfig. 3, nos 2,

3 (synonymy). Osorio & Bahamonde, 1970: 197. Linse, 1997: 59,

pl. 2, figs 5-8, textfig. 12f.

DESCRIPTION. Shell to 4.3 mm; subtrigonal, solid; sculptured by

13-14 strong rounded radial ribs, crossed by concentric, slightly

lamellose, growth lines; margin coarsely crenulated by radial ribs;

no external ligament, internal resilium between beaks; colour whit-

ish with yellow brown periostracum and black staining around

umbos.

HABITAT. Dredged from 10 m on bottom of cobbles, gravel and

coarse sand, and from 10—15 m on cobbles encrusted with calcareous

red algae; uncommon. Ramorino (1968) found densities of up to 155

per m? in the Bahia de Valparaiso, on sandy mud at depths of 65-145

m. Reported from 25-135 m in the Magellan Strait (Linse, 1997).

RECORDS. Stations 7, 14 (3 specimens). Elsewhere Callao (Peru)

to Magellan Strait (Soot-Ryen, 1959; Dell, 1964; Linse, 1997).

Range: 12—54°S.

MOLLUSCA OF SOUTHERN CHILE

REMARKS. This species is extremely similar in external appear-

ance to Carditella tegulata, which occurs in the same habitat.

Carditopsis flabellum flabellum is recognized by the absence of an

external ligament which, although small, is clearly visible behind

the beaks of Carditella tegulata. A subspecies, Carditopsis flabel-

lum malvinae (d’Orbigny, 1846), occurs in the Falkland Islands

(Dell, 1964).

Family MACTRIDAE

Mulinia edulis (King & Broderip, 1832)

(Figure 4L)

Mactra edulis King & Broderip, 1832: 335.

Mulinia edulis — Soot-Ryen, 1959: 66. Osorio & Bahamonde, 1970:

205. Bernard, 1983: 40 (synonymy).

Mulinia byronensis (Gray, 1838) — Soot-Ryen, 1959: 65-66.

Mulinia sp. Osorio, Atria & Mann, 1979: 33-34, fig. 40.

DESCRIPTION. Shell to 77 mm; large, solid, rounded-trigonal,

moderately inflated; sculpture smooth with strong concentric growth

lines; hinge with large internal ligament in deep chondrophoral pit,

cardinal teeth fused to form inverted V below beak; colour white,

texture chalky, with yellow brown periostracum (usually eroded

except near margin).

HABITAT. Living specimens partly buried in soft mud near low

water level, on sheltered shores in brackish conditions (salinities

15-20 %o), sometimes near freshwater stream outflows. This species

is found at low tide in the Magellan Strait (Urban & Tesch, 1996) and

on intertidal and subtidal sandbars, in sediments with a high silt and

clay content, in the estuaries of southern Chile (Jaramillo, Mulson &

Navarro, 1985; Gonzalez & Jaramillo, 1991).

RECORDS. Stations 20, 22, 25. Elsewhere Callao (Peru) to Magellan

Strait (Soot-Ryen, 1959). Range: 12-54°S.

REMARKS. The taxonomy of this genus in southern South America

is confused, as a result of variability in shell outline, and a revision

is required (Soot-Ryen, 1959; Herm, 1969; Osorio et al., 1979). The

present specimens are most similar in shape to M. byronensis which

is, however, probably only a form of the widespread M. edulis.

Shells were present in the extensive shell middens of Isla Traiguén.

Family PHARIDAE

Ensis macha (Molina, 1782)

(Figure 5M)

Solen macha Molina, 1782: 203-204.

Ensis macha — Carcelles, 1950: 81, pl. 5, fig. 92. Soot-Ryen, 1959:

67. Osorio & Bahamonde, 1970: 206. Osorio, Atria & Mann,

1979: 34-35, fig. 41. Bernard, 1983: 41 (synonymy). von Cosel,

1990: 301.

DESCRIPTION. Shell estimated 130 mm (to 211 mm, NHM); thin-

shelled, very elongate, slightly concave dorsally, margins parallel,

ends truncated and gaping, beaks at extreme anterior end; sculpture

smooth, with concentric growth lines; ligament external, hinge with

1 cardinal in right valve, 2 in left, 1 posterior lateral in each valve;

colour white with strong yellow brown periostracum, eroded away

at umbos, internally white.

HABITAT. Single broken dead shell dredged from 5-15 m on

137

bottom of cobbles, mud and shell. This is acommon deep-burrowing

species found in fine sediments in shallow water in southern Chile,

and has been reported at 2-10 m depth in sand and silt (Urban, 1994,

1996) and living in coarse sand at 13 m (to Soot-Ryen, 1959).

Ramorino (1968) found juveniles in sand at 26 m in the Bahia de

Valparaiso.

RECORDS. Station 1. Elsewhere Caldera to Magellan Strait (Soot-

Ryen, 1959; Osorio & Bahamonde, 1970). Range: 27-54°S.

REMARKS. This is a commercially important edible species; the

1997 catch was 5361 tonnes (SERNAP, 1998). The family was more

familiar by the name Cultellidae, but Pharidae has priority (von

Cosel, 1990).

Family SEMELIDAE

Cumingia mutica Sowerby, 1833

(Figure 5G)

Cumingia mutica Sowerby, 1833b: 34. Soot-Ryen, 1959: 65. Olsson,

1961: 372, pl. 66, fig. 4. Osorio & Bahamonde, 1970: 205. Keen,

1971: 257, fig. 658. Dell, 1971: 176-177. Bernard, 1983: 46

(synonymy).

DESCRIPTION. Shell to 25 mm (to 30 mm, NHM); outline rounded

anteriorly and produced posteriorly; sculpture of closely-spaced

concentric growth lines with microscopic radial striae between;

hinge with internal part of ligament attached to large cup-shaped

chondrophore, cardinal teeth weak, strong lateral teeth in right valve

only; colour white, with brown periostracum (worn away except

near margin).

HABITAT. Dead valves dredged from 5—15 m on bottoms of cob-

bles, gravel and coarse sand; uncommon. Other authors have recorded

this species intertidally on sandy mud (Sowerby, 1833b; Soot-Ryen,

1959) and to a depth of 18 m (Dell, 1971).

RECORDS. Stations 1, 7, 14. Elsewhere Guayaquil (Ecuador) to I.

Wellington (Soot-Ryen, 1959; Dell, 1971). Range: 2-49°S.

Family PPAMMOBIIDAE

Tagelus (Tagelus) dombeii (Lamarck, 1818)

(Figure 5K)

Solen dombeii Lamarck, 1818: 454.

Tagelus dombeii — Soot-Ryen, 1959: 61-62. Osorio & Bahamonde,

1970: 204. Osorio, Atria & Mann, 1979: 32, fig. 37. Bernard,

1983: 48 (synonymy).

Tagelus (Tagelus) dombeii — Olsson, 1961: 351, pl. 62, figs 1, 1a, 5

(synonymy).

DESCRIPTION. Shell to 82 mm (to 90 mm, Olsson, 1961); narrowly

elongate, dorsal and ventral margins almost parallel, ends rounded,

valves gaping at either end, beaks central; sculpture smooth with

fine concentric growth lines; hinge weak, 2 cardinal teeth in right

valve, 1 in left; colour purple to brown with paler rays radiating from

umbo, chalky white when eroded, covered by strong brown perio-

stracum, often eroded at umbos, interior white to purple.

HABITAT. Dead shells common on sheltered beaches of silty sand.

This is a deep-burrowing bivalve found in sand and silt (Urban,

1994, 1996). Its distribution is mainly intertidal, with records down

to depths of 16 m (Soot-Ryen, 1959) and 37 m (Ramorino, 1968).

D.G. REID AND C. OSORIO

MOLLUSCA OF SOUTHERN CHILE

RECORDS. Stations 1, 6. Elsewhere El Lagartillo (Panama) to

Golfo Corcovado (Olsson, 1961; Soot-Ryen, 1959), extended south-

ward by the present record. Range: 8°N-46°S.

REMARKS. This is a commercial edible species; the 1997 catch

was 4316 tonnes (SERNAP, 1998).

Family VENERIDAE

Venus antiqua King & Broderip, 1832

(Figure 51)

Venus antiqua King & Broderip, 1832: 336. Fischer-Piette, 1975:

24-25 (synonymy).

Protothaca antiqua — Carcelles, 1950: 80, pl. 5, fig. 86.

Ameghinomya antiqua — Soot-Ryen, 1959: 54—S5, pl. 3, figs 22, 23.

Osorio & Bahamonde, 1970: 202. Dell, 1971: 175-176 (syn-

onymy). Osorio, Atria & Mann, 1979: 29-30, fig. 32. Bernard,

1983: 51 (synonymy).

Protothaca antiqua antiqua — Herm, 1969: 123, pl. 10, figs 2-4, pl.

11, figs 1, 2.

Venus antiqua antiqua — Osorio, Frassinetti & Bustos, 1983: 49-56,

figs 1-11 (synonymy).

DESCRIPTION. Shell to 76 mm; rounded, inflated; sculpture of

numerous strong radial ribs, crossed by fine concentric lamellae, the

lamellae more strongly raised on anterior and posterior slopes;

lunule in front of beaks outlined by deeply incised line; hinge strong,

three cardinal teeth in each valve; margin crenulated internally;

pallial sinus small; colour cream to pale brown, sometimes marked

by tessellated or fine radial chevron pattern in small shells, interior

cream.

HABITAT. On silty sand at low water on sheltered beach; common

embedded in gravel under stones in rock pools in low eulittoral on

moderately sheltered rocky shore; abundant in gravel in shallow

channel with strong tidal currents, 1.5 m depth at high tide; dredged

from 7—15 m depth on bottoms of cobbles and silt; found living at

salinities down to 15—20%c. This is a dominant member of intertidal

and shallow subtidal soft-bottom communities in southern Chile,

and is typically found shallowly buried in mixed silty and stony

substrates (Urban, 1994) and in gravelly muddy sand (Clasing,

Brey, Stead, Navarro & Asencio, 1994). It has been recorded down

to depths of 18-25 m (Soot-Ryen, 1959; Dell, 1971) and 65 m

(Ramorino, 1968).

RECORDS. Stations 1, 7, 14, 15, 22, 25, 26. Elsewhere Callao

(Peru) to Tierra del Fuego (Soot-Ryen, 1959; Osorio et al., 1983).

Range: 12—S5°S.

REMARKS. This species shows variability in shell outline and

degree of development of sculpture. It is an important edible species

and is the major component of ‘almejas’ (including other large

venerid bivalves), of which the 1997 harvest was 12475 tonnes,

largely from Isla Chiloé (SERNAP, 1998). It is an abundant compo-

nent of shell middens on Isla Traiguén and freshly dead shells

indicate that collection for food continues on a small scale in the

area. We do not advocate use of the subspecific epithet, since the

description of the only ‘subspecies’ (P. antiqua tongoyensis Herm,

1969) does not conform to the requirements of either geographical

139

or stratigraphic separation from the typical form. We follow

Fischer-Piette (1975) in assigning this species to the genus Venus,

and we confirm that the date of publication of the original descrip-

tion by King & Broderip is 1832.

Retrotapes exalbidus (Dillwyn, 1817)

(Figure 5J)

Venus exalbida Dillwyn, 1817: 179.

Samarangia exalbida — Carcelles, 1944: 287, pl. 12, figs 93, 94.

Carcelles, 1950: 80, pl. 5, fig. 87.

Eurhomalea exalbida — Soot-Ryen, 1959: 59. Dell, 1964: 219

(synonymy). Osorio & Bahamonde, 1970: 203. Fischer-Piette &

Vukadinovic, 1977: 106—107 (synonymy). Osorio, Atria & Mann,

1979: 30-31, fig. 34.

Retrotapes exalbida — del Rio, 1997: 80-82, figs 22, 23, 41.

DESCRIPTION. Shell to 85 mm (to 106 mm, NHM); large, heavy

venerid; sculptured by raised concentric lamellae, regularly-spaced

1—2 mm apart on young shells, becoming crowded on larger shells,

lunule in front of beaks outlined by groove; internal margin smooth;

hinge with 3 strong cardinal teeth in each valve; colour cream to

brownish, interior white.

HABITAT. Two dead valves dredged from 10-15 m on bottoms of

cobbles, gravel and coarse sand. It has been found living in the low

intertidal zone in the Magellan Strait (Urban & Tesch, 1996),

Carcelles (1950) gave a depth range of S—115 m, and Dell (1964)

recorded specimens from 147 m in the Falkland Islands.

RECORDS. Stations 7, 14. Elsewhere I. Chiloé to Cape Horn

(Carcelles & Williamson, 1951; Fischer-Piette & Vukadinovic,

1977). Range: 42—56°S.

REMARKS. The shell outline and regularity of sculpture are both

variable in this species (Carcelles, 1944; Dell, 1964). This species

has recently been assigned to the new genus Retrotapes by del Rio

(1997); we note that since the Latin noun fapes is masculine,

Retrotapes should take the same gender. It is an edible species, a

component of ‘almejas’ (see V. antiqua).

Tawera gayi (Hupé, 1854)

(Figure 5H)

Venus gayi Hupé, 1854: 337, malacologia pl. 6, fig. Sa—c.

Clausinella gayi—Carcelles, 1944: 287, pl. 13, figs 97, 98. Carcelles,

1950: 80, pl. 5, fig. 88. Soot-Ryen, 1959: 58, pl. 3, figs 26, 27

(synonymy). Herm, 1969: 126, pl. 12, figs 7, 8.

Tawera gayi — Osorio & Bahamonde, 1970: 203. Dell, 1971: 175.

Fischer-Piette & Vukadinovic, 1977: 39-40, fig. 8 (synonymy).

Bernard, 1983: 53 (synonymy).

DESCRIPTION. Shell to 12mm (to 39mm, Carcelles, 1944); rounded

outline; sculptured by fine concentric ridges, of which a few become

irregular and anastomose on anterior and posterior slopes, lunule in

front of beaks outlined by groove; inner margin crenulated; hinge

with three strong cardinal teeth in each valve; colour cream to pale

brown, interior white.

HABITAT. Two dead valves dredged from 10-15 m on bottoms of

cobbles, gravel and coarse sand. Recorded from the tidal zone and

| Fig.7 Scanning electron micrographs of Gastropoda and Bivalvia. A. Jothia coppingeri. B. Puncturella (Puncturella) conica. C. Nodilittorina araucana.

D. Eumetula pulla. E. Glypteuthria meridionalis. ¥. Homalopoma cunninghami. G. Nucula (Nucula) pisum. H, 1. Lasaea miliaris. J. Carditella tegulata.

K. Carditopsis flabellum flabellum. (All specimens from study area; NHM collection).

140

down to 40 m by Soot-Ryen (1959), 65 m (Ramorino, 1968), 5—10

m (Urban & Tesch, 1996) and to 219 m (Linse, 1997).

RECORDS. Stations 7, 14. Elsewhere Coquimbo to Tierra del

Fuego (Fischer-Piette & Vukadinovic, 1977). Range: 30-56°S.

Family HIATELLIDAE

Hiatella solida (Sowerby, 1834)

(Figure SL)

Saxicava solida Sowerby, 1834: 88-89.

Hiatella solida—Soot-Ryen, 1959: 67-68. Olsson, 1961: 425, pl. 77,

fig. 6, 6a. Dell, 1964: 224—226 (synonymy). Osorio & Bahamonde,

1970: 206. Dell, 1971: 177-178. Marincovich, 1973: 14—15, fig.

22. Bernard, 1983: 59. Gordillo, 1995: 193-195, fig. 5.

DESCRIPTION. Shell 12 mm (to 46 mm, Dell, 1964); irregularly

elongate rectangular, often distorted by nestling habit, sometimes

with a strong keel running from umbo to postero-ventral margin,

gaping posteriorly; sculpture of irregular growth lines; hinge often

weak, ligament external; colour white with thin periostracum.

HABITAT. Single specimen in Macrocystis holdfast at 3-5 m depth.

This species has been reported from a wide range of habitats. In the

Beagle Channel, it is found attached by byssus on rocky shores,

among Mytilus clusters, nestling in sand and gravel at low water and

subtidally in Macrocystis holdfasts (Gordillo, 1995). On hard rock

substrates it adopts a nestling habit in crevices, but on soft rock and

on calcareous shells (e.g. of Concholepas concholepas) it becomes

a shallow borer (Gallardo & Osorio, 1978). In the Falkland Islands

it has been recorded from the sublittoral fringe to depths of over 350

m (Dell, 1964).

RECORDS. Station 22. Elsewhere the distribution is unclear owing

to taxonomic uncertainty, but Soot-Ryen (1959) gives Ecuador to

Cape Horn, and Olsson (1961) has a record from the Pearl Islands

(Panama). Range: 8°N—56°S.

REMARKS. As discussed by Dell (1964) the taxonomy of this

genus is confused, because of variation in shell outline and hinge

development. Although he concluded that H. antarctica (Philippi,

1845) was a synonym of H. solida, others have maintained the two

as distinct taxa (Osorio & Bahamonde, 1970; Bernard, 1983).

During this study abundant fossil specimens (up to 36 mm), were

found in the eroding clay cliff of a raised beach on the southwestern

side of Isla Rojas.

Family TEREDINIDAE

Bankia (Bankia) martensi (Stempell, 1899)

(Figure SN—P)

Teredo (Xylotrya) martensi Stempell, 1899: 240, pl. 12, figs 24-27.

Bankia martensi — Turner, 1966: 109, pl. 48, fig. D, pl. 61, figs A—

C, pl. 62, figs A, B (synonymy).

D.G. REID AND C. OSORIO

Bankia (Bankia) martensi — Soot-Ryen, 1959: 70. Osorio &

Bahamonde, 1970: 207. Osorio, Atria & Mann, 1979: 36, fig. 44.

Bernard, 1983: 62.

DESCRIPTION. - Animal to approx. 150 mm, shell to 8 mm, pallets to

35 mm; body elongate, worm-like, enclosed in calcareous tube

bored into wood; shell (Fig. SN) at anterior end, reduced, file-like

surface, white with thin brown periostracum; pair of calcareous

pallets protect siphons at posterior end; pallet (Fig. 50) composed of

central stalk with numerous cone-like elements with fringed border,

each cone extending laterally as a point.

HABITAT. A wood-boring species, abundant in logs in the inter-

tidal zone, recorded down to salinity of 20%c. Reported from the

intertidal to a depth of 55 m (Soot-Ryen, 1959).

RECORDS. Stations 1, 7, 20, 25. Elsewhere Seno Reloncavi to

Magellan Strait (Soot-Ryen, 1959). Range 41—54°S.

DISCUSSION

Ecology and distribution of molluscs in the study

area

During our survey we recorded a total of 62 species of molluscs

during shore collecting and dredging from depths of 5 to 15 m. For

a region at this latitude (46°S) this is not a large number. In part, this

paucity may be explained by the pronounced salinity gradient along

the length of the fjord system. Within the Laguna San Rafael, subject

to meltwater from the San Rafael Glacier, we recorded surface

salinities of 14—15%c (to 17%c, Davenport et al., 1995), and found

but three mollusc species. In the higher and more variable salinity

regime of the Golfo Elefantes (surface salinity 15—21%o, at 15 m

almost certainly greater) the records rose to 18 species. Only in the

main Estero Elefantes were fully marine habitats present (27—33%o)

and in such habitats our total was 56 species. The most euryhaline of

the species was Mytilus edulis chilensis, occurring abundantly at

almost all stations, down to a salinity of 5%o (station 28). Other

euryhaline species were those found on the shore (and therefore

subject to the low surface water salinity) in the Golfo Elefantes:

Plaxiphora aurata, Nacella magellanica, Siphonaria lessonii,

Perumytilus purpuratus, Aulacomya atra, Mulinia edulis and Bankia

martensi. The only species restricted to areas of low salinity were

Chilina patagonica (5—15%c) and Malletia magellanica (14-21%c).

A striking aspect of this molluscan fauna was the dominance of

mytilid bivalves in a range of intertidal and shallow sublittoral

habitats. Most abundant was the euryhaline Mytilus edulis chilensis,

forming dense beds in the mid to lower eulittoral on both exposed

and sheltered shores, and on exposed shores providing a microhabitat

for the limpets Scurria parasitica and Siphonaria lessonii. Peru-

mytilus purpuratus generally occurred with Mytilus edulis chilensis

on the upper shore, and was most common in sheltered sites with

freshwater influence. Aulacomya atra also formed dense beds in the

low eulittoral and sublittoral on wave-exposed coasts, and was

probably common in the sublittoral of shelted sites (where

Fig. 8 Compilation of known geographical ranges for the molluscs recorded in our survey of the Laguna San Rafael, Golfo Elefantes and Estero Elefantes

(see text for sources; 46°S latitude of survey area indicated as LSRNP). Superimposed are the biogeographical provincial boundaries of Brattstr6m &

Johanssen (1983). Antarctic species are those extending south of the Antarctic convergence; Magellanic species are those found only between Cape Horn

and the northern limit of the transitional zone (56—30°S); Peruvian species are those found only within the Peruvian Province and transitional zone (2—

46°S); widespread species are those found in both Magellanic and Peruvian Provinces and (in two cases) extending north of the equator. Arrows indicate

ranges extending beyond the limits shown. Species occurring in the littoral zone and sublittoral fringe are indicated by dots. Note that Xymenopsis

cancellinus is a junior synonym of X. subnodosus

MOLLUSCA OF SOUTHERN CHILE 141

Transitional

Magellanic

<é Prov.» <—. Peruvian Province ——_»

50°S 40°S 30°S 20°S 10°S 0°

lothia corpiagert 4

Puncturella conica

e Lasaea miliaris —_—__

Nacella mytilina _—_——

Margarites violacea Se

Lamellaria ampla __

e Pareuthria powelli ——

Glypteuthria meridionalis —esy

Eumetula pulla —_—_—_—_—

e Trophon plicatus ——

Xymenopsis cancellinus ————

Malletia magellanica —cmomeeat

e Xymenopsis muriciformis —eepe

omalopoma cunninghami

e Pareuthria fuscata See

Xygochlamys patagonica

Retrotapes exalbidus

Adelomelon ancilla —_—

e Tritonia challengeriana Sa

Flabellina falklandica ————

Magellanic species

Nacella magellanica

e Chilina patagonica

e Bankia martensi

Leptochiton medinae

ee ae |

bee See

e Tonicia atrata a

e Fissurella oriens

e Fissurella picta an eanE EERE

e Fissurella nigra a

aie rape eis BD eee a EE

Tawera gayi :

e Argobuccinum pustulosua———_————— ——

Ensis macha —OoeoOY...ne

Nucula pisum

e Acanthina monodon eS a ETS Te

e Mytilus edulis chilensis ——_—_—_----

e Ischnochiton stramineus —_—_—_—_—Olel?.....

e Aulacomya atra

e Venus antiqua oe Ee ee

e Ischnochiton pusio

e Tonicia chilensis

e Scurria ceciliana

Carditelia tenulata BL i a aeREee

Carditopsis Rabelhare i a nt

e Mulinia edulis —_—__—__—___—_—

e Chiton magnificus :

e Crepidula dilatata SS ee

e Diloma nigerrima a

Cierarayens chorus —————————————————_—_—_—_—

e Concholepas concholepas

e Tegula atra jp eS a

—

e Nassarius gayii a

e Siphonaria lessonii —_—_——s— a ae = _eeeeeeeeeeeeeeeeeee

e Perumytilus purpuratus

Hiatella solida

Tagelus dombeii :

Felaniella inconspicua eee Se

Cumingia mutica

c e Chiton granosus ee a a ae

.S | e Scurria parasitica a

5 | e Nodilittorina araucana Seannnnl EnEnERNARRREREERnaaieeemieniaeinEEaiEaeEinEEin

5 | ¢ Chaetopleura peruviana [a7 Gana cea

Q4 | e Trochita trochiformis

142

dense Macrocystis beds made sampling difficult). The large mussel

Choromytilus chorus was not found alive, but probably occurred in

the shallow sublittoral.

The giant kelp Macrocystis provides a habitat for a characteristic

association of molluscs in the Magellanic region. During our survey

we found Leptochiton medinae, Plaxiphora aurata, Fissurella oriens,

Aulacomya atra and Hiatella solida in the holdfasts, and a similar

fauna has been recorded from holdfasts further south, in the Beagle

Channel (Ojeda & Santelices, 1984; but also including Pareuthria,

Xymenopsis and a cerithiopsid). However, on the kelp lamina we

found molluscs to be very scarce, and only occasional specimens of

Nacella mytilina, Fissurella oriens and Flabellina falklandica were

encountered. In the Beagle Channel the kelp lamina supports a larger

community of molluscs, of which the most characteristic are Nacella

mytilina, Margarella violacea, Chlamys vitrea (King & Broderip,

1832) and Gaimardia trapesina (Lamarck, 1819) (King & Broderip,

1832; Castilla, 1985; Waloszek, 1984; D.G. Reid, pers. obs.).

During our survey we did not neglect to examine trawled sedi-

ment and washings from intertidal algae for the presence of small

molluscs. Nevertheless, no small rissoiform gastropods were found.

This is surprising in view of the 23 species, many of them intertidal,

belonging to the families Eatoniellidae, Cingulopsidae and Rissoidae

that were recorded from southern Chile and Tierra del Fuego by

Ponder & Worsfold (1994). Possibly the low and fluctuating salinity

of large parts of the Estero Elefantes fjord system might be con-

nected with the apparent scarcity of small gastropod species in the

shallow-water habitats that we examined.

Biogeographical affinities of the molluscs

Many different authors have discussed the marine biogeographical

‘provinces’ of the west coast of South America, basing their classi-

fications on various taxonomic groups, ecological systems and

depth ranges. Those who have referred specifically to molluscs

include Dall (1909), Carcelles & Williamson (1951), Stuardo (1964),

Dell (1971), Marincovich (1973) and Viviani (1979), and their

conclusions have been summarized, and their data enlarged, by

Brattstr6m & Johanssen (1983). In general there is agreement that

two provinces can be recognized to the south of the tropical zone; a

northern warm-temperate Peruvian Province south of about 2—6°S,

and a southern cold-temperate Magellanic Province from the south-

ern tip of the continent northwards. The boundary between these two

provinces has most often been placed at the northern end of Isla

Chiloé (about 42°S), where numerous marine invertebrates show

their distributional end points. Nevertheless, most authors have

recognized that the division is not a sharp one, and that there is a

broad area of overlap between species that are typical of each

province, so that a transitional zone can be defined, lying between 30

and 46°S (Brattstrom & Johanssen, 1983). Regional classifications

of this kind are susceptible to incomplete data and to problems of

sampling. They are also necessarily somewhat artificial, since the

geographical ranges of different taxa can be determined by various

environmental and biological factors, and influenced by their differ-

ent histories and dispersal capabilities. Nevertheless, they can provide

a useful summary of distributional data.

In this context, our study area is of interest since it lies at the

southern end of the transitional zone (46°S), and in a region of the

Chilean coastline for which distributional data for molluscs is poor.

Most previous studies of Chilean molluscs have concentrated upon

the far south, the Magellan Strait and Tierra del Fuego, and on areas

further to the north, including Isla Chiloé (see Introduction). There-

fore, it is not surprising that of the 62 species we have recorded from

the Laguna San Rafael and Estero Elefantes, 17 (27%) are extensions

D.G. REID AND C. OSORIO

to the known ranges. In the Systematic Descriptions we have

reviewed the published information on the geographical ranges of

these 62 species, and these are tabulated in Figure 8, with the

provincial boundaries of Brattstrom & Johanssen (1983) superim-

posed. Clearly, these data cannot be used in isolation to judge the

validity of biogeographic boundaries, since the sampling of species

is restricted to those occurring in one locality, and is not representa-

tive of the entire Chilean coastline. They do, however, add new

information to the previous compilation and demonstrate the

biogeographic affinities of the fauna we have studied.

In Figure 8 we have divided the species into four categories:

Antarctic (extending south of the Antarctic convergence), Magellanic

(from Cape Horn up to and including the transitional zone, 30—

56°S), widespread (occurring both south and north of the transitional

zone, including two species extending north of the equator) and

Peruvian (occurring in the Peruvian Province up to and including the

transitional zone, 146°S). The predominantly southern (Magellanic)

character of the fauna is apparent, since 30 species (48%) are strictly

Antarctic or Magellanic, and a further 26 of the widespread species

(42%) extend also to the south of our study area. Only five of the

species (8%) are strictly Peruvian. Furthermore, our records are the

northernmost for 11 species, and the southernmost for only 6

species. In their compilation of the distributions of marine inverte-

brates along the western coast of South America, Brattstrom &

Johanssen (1983) included 99 molluscan species; their list was

biased towards the better known Peruvian species, supporting their

assertion that the invertebrate fauna of Chile as a whole was pre-

dominantly northern in character and origin. These authors included

only seven Magellanic molluscs with northern limits at or to the

south of Isla Chiloé (42°S). To these our records add a further 15

species with northern limits between 42-46°S, thus emphasizing the

importance of the southern component of the Chilean fauna, and of

this region as a distributional boundary for many molluscs.

As pointed out by Brattstrom & Johanssen (1983) the biogeo-

graphical composition of the Chilean invertebrate fauna varies with

depth, the southern (Magellanic) component becoming more pro-

nounced in deeper water. Since the water is colder at depth, sublittoral

Magellanicspecies penetrate further north into the transitional zone

than strictly intertidal species. This trend is also evident in our data

(Fig. 8). Of the 26 species found only in our samples dredged from

5-15 m, 65% were Magellanic and Antarctic, 35% widespread and

none Peruvian. Of the remaining 36 species occurring in the eulittoral

zone and sublittoral fringe, 39% were Magellanic, 47% widespread

and 14% Peruvian.

Human exploitation of molluscs

Throughout much of the Chilean coastline the larger molluscs of

intertidal and shallow subtidal habitats are heavily exploited for

food by the local inhabitants (Osorio et al., 1979; Moreno et al.,

1984; Duran et al., 1987; SERNAP, 1998). Edible species found in

the present survey were Chiton granosus, Nacella magellanica,

Fissurella nigra, F- oriens, F- picta, Tegula atra, Trochita trochi-

formis, Argobuccinum pustulosum ranelliforme, Concholepas conch-

olepas, Mytilus edulis chilensis, Choromytilus chorus, Aulacomya

atra, Zygochlamys patagonica, Mulinia edulis, Ensis macha, Tagelus

dombeii, Venus antiqua and Retrotapes exalbidus. Of these, only the

bivalves and Concholepas concholepas are collected in commercial

quantities elsewhere in Chile, and only the three large mytilids are

cultivated. The exploitation of marine molluscs has a long history,

for in precolonial times the indigenous people relied heavily upon

them for food. Evidence of this was found on Isla Traiguén, where

three extensive middens were examined (stations 4, 9, 10), the

MOLLUSCA OF SOUTHERN CHILE

largest of which was about 100 m long and 5 m in depth. The age of

these middens is unknown. They correspond to the ‘white middens’

described in the detailed survey of the archaeological sites of Isla

Traiguén by Curry (in press), consisting largely of intact shells and

fragments of Aulacomya atra, Choromytilus chorus, Venus antiqua

and the large barnacle Megabalanus psittacus, together with a few

shells of Concholepas concholepas, Crepidula dilatata, Trochita

trochiformis and Mulinia edulis. Gathering of molluscs by local

fishermen in the Estero Elefantes evidently continues, since we

found collections of fresh shells of Aulacomya atra, Choromytilus

chorus, Concholepas concholepas and Venus antiqua at several sites

on the shore, although this appears to be on a small scale.

The exploitation of intertidal molluscs has implications not only

for conservation, but also for the general ecology of rocky shores. At

sites in central Chile, it has been demonstrated that where human

interference is prevented there are marked changes in zonation and

community structure. For example, Fissurella species become more

common when no longer gathered for food, grazing down the

previously abundant macroalgae such as /ridaea, and competing

with another grazer, Siphonaria lessonii (Moreno et al., 1984;

Godoy & Moreno, 1989; Duarte et al., 1996). The large mussel

Choromytilus chorus is a prized species, so heavily exploited that it

has disappeared from intertidal habitats in much of its range (Viviani,

1979), yet in a marine reserve an intertidal population soon became

established (Moreno, 1995). The most valuable, and perhaps vulner-

able, of the molluscs exploited in wild populations is Concholepas

concholepas. When intertidal collection is prevented populations on

the shore increase and include large adults that are elsewhere

restricted to the sublittoral zone; furthermore, the dense beds of

Perumytilus purpuratus and barnacles, both preyed upon by

Concholepas concholepas, become dramatically depleted (Castilla

& Duran, 1985; Moreno et al., 1986; Duran et al., 1987). Therefore,

in areas of the Chilean coast with significant human impact the

natural pattern of zonation is much altered. This emphasizes the

importance of conservation of relatively untouched coastlines such

as those of the Laguna San Rafael National Park and adjacent parts

of the Chonos Archipelago.

ACKNOWLEDGEMENTS. The biodiversity research programme in the

Laguna San Rafael National Park, of which this project was a part, was

funded by a grant from the British Government’s Darwin Initiative for the

Survival of Species. For logistic and administrative support we would like to

thank Sam Rose (Raleigh International, London), Keith Tuckwell and Graham

Hornsey (Raleigh International, Chile) and Sergio Herrera (Darwin Project,

CONAF). For their assistance and comradeship in the field we thank our

colleagues Maria Eliana Ramirez (MNHNS), Nick Evans (NHM) and David

John (NHM). This work would not have been possible without the enthusias-

tic participation of the team of Raleigh field staff and venturers who took part

in the Marine Survey of Expedition Chile 98A (January—February 1998);

staff members were Lee David, Kyle Lim, Jaime Plaza and Jill Webber;

venturers were Raimondo Benitez, Kate Bevins, Jo Brown, Nicholas

Edmeades, Stephen Fowler, Juliette Green, Joe Hoffman, Lee Joyce, Isla

McCleery, Peter Mackay-Lewis, Caroline Morgan and Clare Timmins. For

their advice on Chilean molluscs and assistance with the literature we are

most grateful to Pat Curry, Jerry Harasewych (Smithsonian Institution,

Washington, D.C.), Cristian Ituarte (Museo de La Plata, Argentina), Guido

Pastorino (Museo Argentino de Ciencias Naturales) and John Taylor (NHM).

For their comments on the manuscript we gratefully acknowledge Jim

McLean (Los Angeles County Museum of Natural History), Philippe Bouchet

(Muséum National d’ Histoire Naturelle, Paris) and David Jablonski (Univer-

sity of Chicago). Sarah Long (NHM) kindly identified the brachiopod.

Photography was by Harry Taylor (NHM). We acknowledge the support of

the Departamento de Investigacion y Desarrollo de la Universidad de Chile.

143

REFERENCES

Alvarado, J. L. & Castilla, J. C. 1996. Tridimensional matrices of mussels Perumytilus

purpuratus on intertidal platforms with varying wave forces in central Chile. Marine

Ecology Progress Series 133: 135-141.

Arnaud, P. M. 1972. Invertébrés marins des XI[éme et X Veme expéditions antarctiques

frangaises en Terre Adélie. 8. — Gastéropodes prosobranches. Téthys Supplément

4:105—134.

Benedetti—Cecchi, L. & Cinelli, F. 1997. Spatial distribution of algae and inverte-

brates in the rocky intertidal zone of the Strait of Magellan: are patterns general?

Polar Biology 18: 337-343.

Bergh, L. S. R. 1884. Report on the Nudibranchiata. Report on the Scientific Results of

the Voyage of H.M.S. Challenger During the Years 1873-76. Zoology 10: 1-151.

Bernard, F. R. 1983. Catalogue of the living Bivalvia of the Eastern Pacific Ocean:

Bering Strait to Cape Horn. Canadian Special Publication of Fisheries and Aquatic

Sciences 61: 1-102.

Beu, A. G. 1970. Taxonomic position of Lippistes pehuensis Marwick, with a review

of the species of Concholepas (Gastropoda, Muricidae). Journal of the Malacological

Society of Australia 2: 39-46.

1985a. A classification and catalogue of living world Ranellidae (=Cymatiidae)

and Bursidae. Conchologists of America Bulletin 13: 55-66.

1985b. Pleistocene Chlamys patagonica delicatula (Bivalvia: Pectinidae) off

southeastern Tasmania, and history of its species group in the Southern Ocean.

Special Publication, South Australian Department of Mines and Energy 5: \-11.

Blainville, H. M. D. de 1827. Siphonaire. Planches deuxiéme partie: Régne Organisé,

Zoologie. pp. 291-296. In: Levrault, F. G. (ed.) Dictionnaire des Sciences Naturelles

49. Strasbourg & Paris.

Born, I. von 1778. Index Rerum Naturalium Musei Caesarei Vindobonensis. Pars

Prima, Testacea. Vienna.

Bouchet, P. & Warén, A. 1993. Revision of the northeast Atlantic bathyal and abyssal

Mesogastropoda. Bollettino Malacologico, Supplemento 3: 579-840.

Brace, R. C. 1983. Observations on the morphology and behaviour of Chilina fluctuosa

Gray (Chilinidae), with a discussion on the early evolution of pulmonate gastropods.

Philosophical Transactions of the Royal Society of London, Series B 300: 463-491.

Brattstrom, H. 1990. Intertidal ecology of the northernmost part of the Chilean

archipelago. Report 50 of the Lund University Chile Expedition 1948-49. Sarsia 75:

107-160.

Brattstrom, B. & Johanssen, A. 1983. Ecological and regional zoogeography of the

marine benthic fauna of Chile. Report no. 49 of the Lund University Chile Expedi-

tion 1948-49. Sarsia 68: 289-339.

Bretos, M., Gutiérrez, J. & Espinoza, Z. 1988. Estudios biol6gicos para el manejo de

Fissurella picta. Medio Ambiente 9: 28-34.

Bretos, M., Quintana, V. & Ibarrola, V. 1988. Bases bioldgicas para el manejo de

Fissurella nigra. Medio Ambiente 9: 55-62.

Broderip, W. J. & Sowerby, G. B. 1832. Characters of new species of Mollusca and

Conchifera, collected by Mr Cuming. Proceedings of the Zoological Society of

London 1832: 104-108.

— 1833. [Collection of shells formed by Mr. Cuming on the western coast of South

America, and among the islands of the southern Pacific Ocean]. Proceedings of the

Zoological Society of London 1832: 194-202.

Bruguieére, J. 1789. Encyclopédie Méthodique. Histoire Naturelle des Vers. 1.

Bullock, R. C. 1988. The genus Chiton in the New World (Polyplacophora: Chitonidae).

Veliger 31: 141-191.

Canete, J. I. & Ambler, R. P. 1992. Desarrollo intracapsular del gastropodo comestible

Calyptraea (Trochita) trochiformis (Born, 1778), en Chile. Revista Chilena de

Historia Natural 65: 255-266.

Carcelles, A. R. 1944. Catalogo de los moluscos marinos de Puerto Quequén. Revista

del Museo de La Plata. Nueva Serie, Zoologia 3: 233-309.

1950. Catalogo de los moluscos marinos de la Patagonia. Anales del Museo

Nahuel Huapi 2: 41-100.

1954. Especies sudamericanas de Argobuccinum Bruguiére 1792. Comunicaciones

del Instituto Nacional de Investigacion de las Ciencias Naturales 2: 243-254.

Carcelles, A. R. & Williamson, S. I. 1951. Catalogo de los moluscos marinos de la

Provincia Magellanica. Revista del Instituto Nacional de Investigacion de las

Ciencias Naturales 2: 225-383.

Castellanos, Z. A. de 1979. Micromoluscos poco conocidos del sur Argentino-

Chileno. Neotropica 25: 133-140.

1990. Catalogo Descriptivo de la Malacofauna Marina Magellanica 5. Comision

de Investigaciones Cientificas, Buenos Aires.

1992. Catalogo Descriptivo de la Malacofauna Marina Magellanica 7 & 8.

Comisién de Investigaciones Cientificas, Buenos Aires.

Castellanos, Z. A. de & Gaillard, M. C. 1981. Mollusca Gasteropoda Chilinidae.

Fauna de Agua Dulce de la Republica Argentina 15: 19-51.

Castellanos, Z. A. de & Landoni, N. 1988. Catalogo Descriptivo de la Malacofauna

Marina Magellanica 2. Comision de Investigaciones Cientificas, Buenos Aires.

1989. Catalogo Descriptivo de la Malacofauna Marina Magellanica 3. Comision

de Investigaciones Cientificas, Buenos Aires.

144

—1992. Catalogo Descriptivo de la Malacofauna Marina Magellanica 10. Comisi6n

de Investigaciones Cientificas, Buenos Aires.

1993. Catalogo Descriptivo de la Malacofauna Marina Magellanica 9.

Neogastropoda. Comisién de Investigaciones Cientificas, Buenos Aires.

Castilla, J. C. 1982. Pesqueria de moluscos gastropodos en Chile: Concholepas

concholepas, un caso de estudio. Monografias Biologicas 2: 199-212.

1985. Food webs and functional aspects of the kelp, Macrocystis pyrifera, com-

munity in the Beagle Channel, Chile. pp. 407-414. In: Siegfried, W. R., Condy, P. R. &

Laws, R. M. (eds) Antarctic Nutrient Cycles and Food Webs. Springer-Verlag, Berlin.

Castilla, J. C. & Cancino, J. 1976. Spawning behaviour and egg capsules of

Concholepas concholepas (Mollusca: Gastropoda: Muricidae). Marine Biology 37:

255-263.

Castilla, J. C. & Duran, L. R. 1985. Human exclusion from the rocky intertidal zone

of central Chile: the effects on Concholepas concholepas (Gastropoda). Oikos 45:

391-399.

Castilla, J. C., Guisado, C. & Cancino, J. 1979. Aspectos ecolégicos y conductuales

relacionados con la alimentacion de Concholepas concholepas (Mollusca: Gastro-

poda: Muricidae). Biologia Pesquera 12: 99-114.

Cazzaniga, N. J. 1994. A concern for grammar: the name of the Magellanic mussel

(Bivalvia: Mytilidae). Malacological Review 27: 110.

Cernohorsky, W. O. 1975. The taxonomy of some West American and Atlantic

Nassariidae based on their type-specimens. Records of the Auckland Institute and

Museum 12: 121-173.

1977. The taxonomy of some Southern Ocean Mollusca (Gastropoda) mainly

Antarctic and Subantarctic. Records of the Auckland Institute and Museum 14: 105—

119.

1984. Systematics of the family Nassartidae (Mollusca: Gastropoda). Bulletin of

the Auckland Institute and Museum 14: 1-356.

Chavan, A. 1969. Superfamily Carditacea Fleming, 1820. pp. 543-561. In: Moore, R.

C. (ed.) Treatise on Invertebrate Paleontology. Part N. Mollusca 6. Geological

Society of America, Lawrence, Kansas.

Clasing, E., Brey, T., Stead, R., Navarro, J. & Asencio, G. 1994. Population

dynamics of Venus antiqua (Bivalvia: Veneracea) in the Bahia de Yaldad, Isla de

Chiloé, southern Chile. Journal of Experimental Marine Biology and Ecology 177:

171-186.

Clench, W. J. & Turner, R. D. 1964. The subfamilies Volutinae, Zidoninae, Odonto-

cymbiolinae and Calliotectinae in the western Atlantic. Johnsonia 4: 129-180.

Cosel, R. von 1990. An introduction to the razor shells (Bivalvia: Solenacea). pp. 283—

311. In: Morton, B. (ed.) The Bivalvia — Proceedings of a Memorial Symposium in

Honour of Sir Charles Maurice Yonge, Edinburgh, 1986. Hong Kong University

Press, Hong Kong.

Curry, P. J. In press. Archaeology. In: Aldridge, D. (ed.) Laguna San Rafael National

Park, Chile. The Natural History of a Patagonian Wilderness.

Dall, W. H. 1909. Report on a collection of shells from Peru, with a summary of the

littoral marine Mollusca of the Peruvian zoological province. Proceedings of the

United States National Museum 37: 147-294.

Davenport, J. & others 1995. The marine ecology of the Laguna San Rafael (southern

Chile): ice scour and opportunism. Estuarine, Coastal and Shelf Science 41: 21-37.

Deambrosi, D. F. de 1969. La radula como caracter diagnostico en los generos

Margarella y Margarita y nueva ubicacion de algunas especies — (Mollusca). Acta

Zoologica Lilloana 24: 50-55.

Dell, R. K. 1964. Antarctic and subantarctic Mollusca: Amphineura, Scaphopoda and

Bivalvia. Discovery Reports 33: 93-250.

1971. The marine Mollusca of the Royal Society Expedition to Southern Chile,

1958-1959. Records of the Dominion Museum 7: 155-233.

1972. Notes on nomenclature of some Mollusca from Antarctica and southern

South America. Records of the Dominion Museum 8: 21-42.

1990. Antarctic Mollusca with special reference to the fauna of the Ross Sea.

Bulletin of the Royal Society of New Zealand 27: 1-311.

DeVries, T. J. 1995. Concholepas Lamarck, 1801 (Neogastropoda: Muricoidea): a

Neogene genus native to South America. Veliger 38: 284-297.

Dillwyn, L. W. 1817. A Descriptive Catalogue of Recent Shells 2. J. & A. Arch,

London.

DiSalvo, L. H. 1988. Observations on the larval and post-metamorphic life of

Concholepas concholepas (Bruguiére, 1789) in laboratory culture. Veliger 30: 358—

368.

Duarte, W. E., Asencio, G. & Moreno, C. A. 1996. Long-term changes in population

density of Fissurella picta and Fissurella limbata (Gastropoda) in the marine reserve

of Mehuin, Chile. Revista Chilena de Historia Natural 69: 45-56.

Duran, L. R., Castilla, J. C. & Oliva, D. 1987. Intensity of human predation on rocky

shores at las Cruces in central Chile. Environmental Conservation 14: 143-149.

Eliot, C. N. E. 1907. Nudibranchs from New Zealand and the Falkland Islands.

Proceedings of the Malacological Society of London 7: 327-361.

Espoz, C., Guzman, G. & Castilla, J. C. 1995. The lichen Thelidium litorale on shells

of intertidal limpets: a case of lichen-mediated cryptic mimicry. Marine Ecology

Progress Series 119: 191-197.

Ferreira, A. J. 1982. Taxonomic notes on Chiton carmichaelis Gray, 1828, type

species of Plaxiphora Gray, 1847. Veliger 25: 43-50.

D.G. REID AND C. OSORIO

1983. The genus Chaetopleura Shuttleworth, 1853 (Mollusca: Polyplacophora) in

the warm-temperate and tropical Eastern Pacific, Southern California to Peru, with

the description of two new species. Veliger 25: 203-224.

Fischer-Piette, E. & Vukadinovic, D. 1977. Suite des révisions des Veneridae (Moll.

Lamellibr.) Chioninae, Samaranginae et complément aux Venus. Mémoires du Muséum

National d’Histoire Naturelle. Nouvelle Serie. Série A, Zoologie 106: 1-186.

Fischer-Piette, F. 1975. Révision des Venerinae s.s. (Mollusques Lamellibranches).

Mémoires du Muséum National d’Histoire Naturelle. Nouvelle Serie. Série A,

Zoologie 93: |-64.

Frembly, J. 1827. A description of several new species of chitones, found on the coast

of Chili, in 1825; with a few remarks on the method of taking and preserving them.

Zoological Journal 3: 193-205.

Gallardo, C. & Osorio, C. 1978. Hiatella solida (Sowerby, 1834) (Mollusca: Hiatel-

lidae) on Concholepas concholepas (Bruguiére, 1789) and other substrates. Veliger

20: 274-278.

Gallardo, C. S. 1977. Two modes of development in the morphospecies Crepidula dilat-

ata (Gastropoda: Calyptraeidae) from southern Chile. Marine Biology 39: 241-251.

1979. Especies gemelas del genero Crepidula (Gastropoda, Calyptraeidae) en la

costa de Chile; una redescription de C. dilatata Lamarck y description de C. fecunda

n. sp. Studies on Neotropical Fauna and Environment 14: 215-226.

Gmelin, J. F. 1791. Caroli a Linné . . . Systema Naturae per Regna Tria Naturae. 1,

part 6. Edition 13. Lugduni.

Godoy, C. & Moreno, C. A. 1989. Indirect effects of human exclusion from rocky inter-

tidal in southern Chile: a case of cross-linkage between herbivores. Oikos 54: 101-106.

Gonzalez, M. & Jaramillo, E. 1991. The association between Mulinia edulis (Mol-

lusca, Bivalvia) and Edotea magellanica (Crustacea, Isopoda) in southern Chile.

Revista Chilena de Historia Natural 64: 37-51.

Gordillo, S. 1995. Subfossil and living Hiatella solida (Sowerby) from the Beagle

Channel, South America. Quaternary of South America and Antarctic Peninsula 9:

183-204.

Gosling, E. 1992. Systematics and geographical distribution of Myrilus. pp. 1-20. In:

Gosling, E. (ed.) The Mussel Mytilus: Ecology, Physiology, Genetics and Culture.

Elsevier, Amsterdam.

Gray, J-E. 1839. Molluscous animals. pp. 101-155. In: Beechey, F.W. (ed.) The

Zoology of Captain Beechey’s Voyage. H.G. Bohn, London.

Gruber, G. L. & Carriker, M. R. 1990. A note on the accessory boring organ and shell

boring by the ‘loco’, Concholepas concholepas (Muricidae, Gastropoda). Bulletin of

Marine Science 47: 739-744.

Guiler, E. R. 1959a. Intertidal belt-forming species on the rocky coasts of northern

Chile. Papers and Proceedings of the Royal Society of Tasmania 93: 33-58.

1959b. The intertidal ecology of the Montemar area, Chile. Papers and Proceed-

ings of the Royal Society of Tasmania 93: 165-183.

Guzman, M. L. 1978. Patron de distribucién espacial y densidad de Nacella magellanica

(Gmelin, 1791) en el intermareal del sector oriental del estrecho de Magallanes

(Mollusca, Gastropoda). Anales del Instituto de la Patagonia 9; 205-219.

Haeckel, W. 1911. Beitrage zur Anatomie der Gattung Chilina. Zoologische Jahrbiicher.

Supplement 13: 89-136.

Helbling, G. S. 1779. Beytrage zur Kenntnis neuer und seltener Konchylien.

Abhandlungen einer Privatgesellschaft in B6hmen 4: 102-131.

Herbert, D. G. & Kilburn, R. N. 1986. Taxonomic studies on the Emarginulinae

(Mollusca: Gastropoda: Fissurellidae) of southern Africa and Mozambique.

Emarginula, Emarginella, Puncturella, Fissurisepta and Rimula. South African

Journal of Zoology 21: 1-27.

Herm, D. 1969. Marines Pliozaén und Pleistozaén in Nord- und Mittel-Chile unter

besonderer Beriicksichtigung der Entwicklung der Mollusken-Faunen. Zitteliana 2:

1-159.

Hickman, C. S. & McLean, J. H. 1990. Systematic Revision and Suprageneric

Classification of Trochacean Gastropods. 169 p. Natural History Museum of Los

Angeles County, Los Angeles.

Hoagland, K. E. 1977. Systematic review of fossil and Recent Crepidula and discus-

sion of evolution of the Calyptraeidae. Malacologia 16: 353-420.

Hockey, P. A., Bosman, A. L. & Ryan, P. G. 1987. The maintenance of polymorphism

and cryptic mimesis in the limpet Scurria variabilis by two species of Cinclodes

(Aves: Furnartinae) in central Chile. Veliger 30: 5-10.

Houbrick, R. S. 1987. Description of a new, giant Ataxocerithium species from

Australia with remarks on the systematic placement of the genus (Prosobranchia:

Cerithiopsidae). Nautilus 101: 155-161.

Hubendick, B. 1946. Systematic monograph of the Patelliformia. Kungliga Svenska

Vetenskapsakademiens Handlingar. Ser. 3 23(5): 1-93.

Hupé, H. 1854. Fauna Chilena. Moluscos. pp. 1-476. In: Gay, C. (ed.) Historia Fisica

y Politica de Chile. Zoologia 8. Paris.

Ituarte, C. F. 1997. Chilina megastoma Hylton Scott, 1958 (Pulmonata: Basommat-

ophora): a study on topotypic specimens. American Malacological Bulletin 14: 9-15.

Jara, H. F. & Moreno, C. A. 1984. Herbivory and structure in a midlittoral rocky

community: a case in southern Chile. Ecology 65: 28-38.

Jaramillo, E., Mulson, S. & Navarro, R. 1985. Intertidal and subtidal macroinfauna

in the Queule River Estuary, south of Chile. Revista Chilena de Historia Natural 58:

127-137.

MOLLUSCA OF SOUTHERN CHILE

Jordan, J. & Ramorino, L. 1975. Reproduccion de Littorina (Austrolittorina) peruvi-

ana (Lamarck, 1822) y Littorina (Austrolittorina) araucana d’Orbigny, 1840.

Revista de Biologia Marina 15: 227-261.

Kaas, P. & Van Belle, R. A. 1985. Monograph of Living Chitons (Mollusca:

Polyplacophora). Volume 1. Order Neoloricata: Lepidopleurina. E. J. Brill & W.

Backhuys, Leiden.

1987. Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 3.

Suborder Ischnochitonina. Ischnochitonidae: Chaetopleurinae, & Ischnochitoninae

(pars). Additions to Vols 1 & 2. E. J. Brill & W. Backhuys, Leiden.

1990. Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 4.

Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (continued). Addi-

tions to Vols 1, 2 and 3. E. J. Brill, Leiden.

1994. Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 5.

Suborder Ischnochitonina: Ischnochitonidae (concluded), Callistoplacinae;

Mopaliidae. Additions to Vols 1-4. E. J. Brill, Leiden.

1998. Catalogue of Living Chitons (Mollusca, Polyplacophora). Backhuys Pub-

lishers, Leiden.

Keen, A. M. 1971. Sea Shells of Tropical West America. 1064 p. Stanford University

Press, Stanford.

Kiener, L.-C. 1834. Genre Buccin. pp. 1-112. In: Kiener, L.-C. (ed.) Spécies Général

et Iconographie des Coquilles Vivantes, Part 10. Rousseau and Bailliére, Paris.

Kilburn, R. N. & Rippey, E. 1982. Sea Shells of Southern Africa. 249 p. Macmillan

South Africa, Johannesburg.

King, P. P. & Broderip, W. J. 1832. Description of the Cirrhipeda, Conchifera and

Mollusca, in a collection formed by the officers of H.M.S. Adventure and Beagle

employed between the years 1826 and 1830 in surveying the southern coasts of South

America, including the Straits of Magalhaens and the coast of Tierra del Fuego.

Zoological Journal 5: 332-349.

Kool, S. P. 1993. Phylogenetic analysis of the Rapaninae (Neogastropoda: Muricidae).

Malacologia 35: 155-259.

Lamarck, J. B. P. A. de M. de 1818, 1819, 1822. Histoire Naturelle des Animaux Sans

Vertébres. 5, 6. Paris.

Lamy, E. 1922. Révision des Carditacea vivants du Muséum National d’ Histoire

Naturelle de Paris (suite). Journal de Conchyliologie 66: 289-368.

Leloup, E. 1956. Reports of the Lund University Chile Expedition 1948-49. 27.

Polyplacophora. Lunds Universitets Arsskrift, N. F. Avd. 2 52(15): 1-94.

Lesson, R. P. 1831. Mollusques. pp. 239-448. In: Duperrey, M. L. I. (ed.) Voyage

Autour du Monde, Exécuté par Ordre du Roi, sur la Corvette de Sa Majesté, La

Coquille, pendant les Anneés 1822, 1823, 1824 et 1825. Zoologie , 2(1). Paris.

Lewis, J. R. 1964. The Ecology of Rocky Shores. English University Press, London.

Lightfoot, J. 1786. A Catalogue of the Portland Museum. London.

Lindberg, D. R. 1988. The Patellogastropoda. Malacological Review. Supplement 4:

35-63.

Linnaeus, C. 1758. Systema Naturae per Regna Tria Naturae, Secundum Classes,

Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis 1.

Edition 10. Laurentii Salvii, Holmiae.

Linse, K. 1997. Die Verbreitung epibenthischer Mollusken im chilenischen Beagle-

Kanal. Berichte zur Polarforschung 228: 1-131.

Linse, K. & Brandt, A. 1998. Distribution of epibenthic Mollusca on a transect

through the Beagle Channel (southern Chile). Journal of the Marine Biological

Association of the United Kingdom 78: 875-889.

Lopez-Gappa, J. & Tablado, A. 1997. Growth and production of an intertidal

population of the chiton Plaxiphora aurata (Spalowski, 1795). Veliger 40: 263-270.

Lozada, E. 1968. Contribucion al estudio de la cholga Aulacomya ater en Putemtn.

Biologia Pesquera 3: 3-39.

Lozada, E., Rolleri, J. & Yanez, R. 1971. Consideraciones biol6gicas de Choromytilus

chorus en dos sustratos diferentes. Biologia Pesquera 5: 61-108.

Mabille, J. & Rochebrune, A. T. 1889. Mollusques. In: Mission Scientifique du Cap

Horn, 1882-3. 6, Zoology 2. Paris.

Malusa, J. A. 1985. Attack mode in a predatory gastropod: labial spine length and the

method of prey capture in Acanthina angelica Oldroyd. Veliger 28: 1-5.

Marcus, E. 1959. Reports of the Lund University Chile Expedition 1948-49. 36. Lamel-

lariacea und Opisthobranchia. Lunds Universitets Arsskrift, N. F. Avd. 2 55(9): 1-133.

Maxwell, P. A. 1988. Comments on ‘A reclassification of the Recent genera of the

subclass Protobranchia (Mollusca: Bivalvia)’ by J. A. Allen and F. J. Hannah (1986).

Journal of Conchology 33: 85-96.

McDonald, J. H., Seed, R. & Koehn, R. K. 1991. Allozymes and morphometric

characters of three species of Mytilus in the Northern and Southern Hemispheres.

Marine Biology 111: 323-333.

McLean, J. H. 1984. Systematics of Fissurella in the Peruvian and Magellanic faunal

provinces (Gastropoda: Prosobranchia). Contributions in Science, Natural History

Museum of Los Angeles County 354: 1-70.

Melvill, J. C. & Standen, R. 1912. The marine Mollusca of the Scottish National

Antarctic Expedition. Part Il. Transactions of the Royal Society of Edinburgh 48:

333-366.

Miranda, O. & Acuna, E. 1979. Mytilus edulis chilensis (Hupé, 1854) en Cabo Negro

(Provincia de Magellanes) (Mollusca, Bivalvia, Mytilidae). Revista de Biologia

Marina 16: 331-353.

145

Molina, G. I. 1782. Saggio sulla Storia Naturale del Chili. T. d’ Aquino, Bologna.

Moreno, C. A. 1995. Macroalgae as a refuge from predation for recruits of the mussel

Choromytilus chorus (Molina, 1782) in southern Chile. Journal of Experimental

Marine Biology and Ecology 191: 181-193.

Moreno, C. A. & Jaramillo, E. 1983. The role of grazers in the zonation of intertidal

macroalgae of the Chilean coast. Oikos 41: 73-76.

Moreno, C. A., Lunecke, K. M. & Lepez, M. I. 1986. The response of an intertidal

Concholepas concholepas (Gastropoda) population to protection from man in

southern Chile and the effects on benthic sessile assemblages. Oikos 46: 359-364.

Moreno, C. A., Reyes, A. & Asencio, G. 1993. Habitat and movements of the recruits

of Concholepas concholepas (Mollusca; Muricidae) in the rocky intertidal of

southern Chile. Journal of Experimental Marine Biology and Ecology 171: 51-61.

Moreno, C. A., Sutherland, J. P. & Jara, H. F. 1984. Manas a predator in the intertidal

zone of southern Chile. Oikos 42: 155-160.

Morrison, J. P. E. 1963. Notes on American Siphonaria. American Malacological

Union Annual Reports 1963: 7-9.

Moskaley, L. I. 1977. A revision of the Lepetidae (Gastropoda, Prosobranchia) of the

worldocean. Trudy Instituta Okeanologii im. P. P. Shirshova 108: 52-78. (In Russian).

Navarro, J. M. 1988. The effects of salinity on the physiological ecology of

Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae). Journal of Experimental

Marine Biology and Ecology 122: 19-33.

(0) Foighil, D. & Smith, M. J. 1995. Evolution of asexuality in the cosmopolitan marine

clam Lasaea. Evolution 49: 140-150.

Ojeda, F. P. & Santelices, B. 1984. Invertebrate communities in holdfasts of the kelp

Macrocystis pyrifera from southern Chile. Marine Ecology — Progress Series 16:

65-73.

Oliva, D. & Castilla, J. C. 1992. Guia para el reconocimiento y morphometria de diez

especies del género Fissurella Bruguiere, 1789 (Mollusca: Gastropoda) comunes en

la pesqueria y conchales indigenas de Chile Central y Sur. Guyana, Zoologia 56: 77—

108.

Olivier, S. R. & Penchaszadeh, P. E. 1968. Observaciones sobre la ecologia y biologia

de Siphonaria (Pachysiphonaria) lessoni (Blainville, 1824) (Gastropoda,

Siphonariidae) en la litoral rocoso de Mar del Plata (Buenos Aires). Cahiers de

Biologie Marine 9: 469-491.

Olsson, A. A. 1961. Mollusks of the Tropical Eastern Pacific. Panamic-Pacific

Pelecypoda. Paleontological Research Institution, Ithaca, New York.

Orbigny, A. d’ 1834-1847. Voyage dans l’Amérique Méridionale 5 (3): Mollusques. P.

Bertrand, Paris.

Osorio, C., Atria, J. & Mann, S. 1979. Moluscos marinos de importancia econédmica

en Chile. Biologia Pesquera 11: 3-47.

Osorio, C. & Bahamonde, N. 1970. Lista preliminar de Lamelibranquios de Chile.

Boletin del Museo Nacional de Historia Natural 31: 185-256.

Osorio, C., Frassinetti, D. & Bustos, E. 1983. Taxonomia y morfometria de Venus

antiqua antiqua King y Broderip, 1835 (Mollusca, Bivalvia, Veneridae). Téthys 11:

49-56.

Otaiza, R. D. & Santelices, B. 1985. Vertical distribution of chitons (Mollusca:

Polyplacophora) in the rocky intertidal zone of central Chile. Journal of Experimen-

tal Marine Biology and Ecology 86: 229-240.

Pallas, P. S. 1774. Spicilegia Zoologica Quibus Novae Imprimis et Obscurae

Animalium Species. Part 10. Berolini, Lange.

Palmer, A. R. 1990. Effect of crab effluent and scent of damaged conspecifics on

feeding, growth, and shell morphology of the Atlantic dogwhelk Nucella lapillus

(L.). Hydrobiologia 193: 155-182.

Pastorino, G. & Harasewych, M.G. 2000. A revision of the Patagonian genus

Xymenopsis Powell, 1951 (Gastropoda: Muricidae). Nautilus 114: 38-58.

Paterson, G. L. J., John, D. M., Spencer-Jones, M., Ramirez, M. E., Evans, N. J.,

Davenport, J., Manly, R., Reid, D. G., Osorio, C., Clark, P. F., Plaza, J., Rose, S.

& Letelier, S. In press. Marine biology of the Laguna San Rafael National Park. In:

Aldridge, D. (ed.) Laguna San Rafael National Park, Chile. The Natural History of

a Patagonian Wilderness.

Perry, D. M. 1985. Function of the shell spine in the predaceous rocky intertidal snail

Acanthina spirata (Prosobranchia: Muricacea). Marine Biology 88: 51-58.

Philippi, R. A. 1845. Diagnosen einiger neuen Conchylien. Archiv fiir Naturgeschichte

11: 50-71.

1845-1847. Abbildungen und Beschreibungen neuer oder wenig gekannter

Conchylien 2. Theodor Fischer, Cassel.

Pickard, G. L. 1971. Some physical oceanographic features of inlets of Chile. Journal

of the Fisheries Research Board of Canada 28: 1077-1106.

Plate, L. H. 1899. Die Anatomie und Phylogenie der Chitonen. Fortsetzung. Zoologische

Jahrbiicher Supplement-band 5: 15-216.

Ponder, W. F. & Worsfold, T. M. 1994. A review of the rissoiform gastropods of south-

western South America (Mollusca, Gastropoda). Contributions in Science 445: 1-63.

Poppe, G. T. & Goto, Y. 1992. Volutes. Mostra Mondiale Malacologia, Cupra

Marittima, Italy.

Powell, A. W. B. 1951. Antarctic and subantarctic Mollusca: Pelecypoda and Gastro-

poda. Discovery Reports 26: 47-196.

1960. Antarctic and subantarctic Mollusca. Records of the Auckland Institute and

Museum 5: 117-193.

146

— 1973. The patellid limpets of the world. Indo-Pacific Mollusca 3: 75-205.

1979. New Zealand Mollusca. 500 p. Collins, Auckland.

Rabi, M., Yamashiro, C. & Quiroz, M. 1996. Revision de la biologia y pesqueria del

recurso chanque Concholepas concholepas (Bruguiére, 1789) (Mollusca: Gastro-

poda: Muricidae). Informe Progresivo. Instituto del Mar del Peri 31: 3-23.

Ramirez, J. 1974. Nuevas especies chilenas de Lucapina, Fissurella y Collisella

(Mollusca, Archaeogastropoda). Boletin del Museo Nacional de Historia Natural

33: 15-34.

Ramorino, L. 1968. Pelecypoda del fondo de la Bahia de Valparaiso. Revista de

Biologia Marina 13: 175-285.

Reeve, L. A. 1843. Monograph of the genus Cardita. Pls 1-9. In: Reeve, L. A. (ed.)

Conchologia Iconica. L. A. Reeve, London.

—— 1844. Description of new species of shells figured in the ‘Conchologia Iconica’.

Proceedings of the Zoological Society of London 1843: 168-197.

1854. Monograph of the genus Patella. Pls 1-16 (1857), 17-18 (1858). In: Reeve,

L. A. (ed.) Conchologia Iconica. L. A. Reeve, London.

Rehder, H. A. 1943. The molluscan genus Trochita Schumacher with a note on

Bicatillus Swainson. Proceedings of the Biological Society of Washington 56: 41—

46.

Reid, D. G. 1989. The comparative morphology, phylogeny and evolution of the

gastropod family Littorinidae. Philosophical Transactions of the Royal Society of

London. Series B 324: 1-110.

— 1996. Systematics and Evolution of Littorina. 463 p. Ray Society, London.

Reid, H. P. 1974. La trayectoria del ducto digestivo de Mytilus chilensis Hupé, 1854 y

su valor sistematico. Boletin de la Sociedad de Biologia de Concepcion 48: 179-184.

Rio, C. J. del 1997. Cenozoic biogeographic history of the eurythermal genus Retro-

tapes, new genus (subfamily Tapetinae) from southern South America and Antarctica.

Nautilus 110: 77-93.

Romo, H. & Alveal, K. 1977. Los comunidades de litoral rocoso de Punta Ventanilla

Bahia de Quintero — Chile. Gayana Miscelanea 6: \-41.

Ruiz, E. & Giampaoli, L. 1981. Estudios distribucionales de la flora y fauna costera de

Caleta Cocholgue, Bahia de Concepcion — Chile. Boletin de la Sociedad de Biologia

de Concepcion 52: 145-166.

Santelices, B. 1991. Littoral and sublittoral communities of continental Chile. pp. 347—

369. In: Mathieson, A. C. & Nienhuis, P. H. (eds) Intertidal and Littoral Ecosystems.

Ecosystems of the World 24. Elsevier, Amsterdam.

Sasaki, T. 1998. Comparative anatomy and phylogeny of the Recent Archaeogastropoda

(Mollusca: Gastropoda). Bulletin. University Museum, University of Tokyo 38: \—

224.

Schrodl, M. 1996. Nudibranchia y Sacoglossa de Chile: morpholgia externa y

distribucion. Gayana Zoologia 60: 17-62.

— 1997. Range extensions of Magellanic nudibranchs (Opisthobranchia) into the

Peruvian faunal province. Veliger 40: 38-42.

Seed, R. 1992. Systematics evolution and distribution of mussels belonging to the

genus Mytilus: an overview. American Malacological Bulletin 9: 123-137.

Servicio Nacional de Pesca. 1998. Anuario Estadistico de Pesca 1997. Departamento

de Sistemas de Informacién y Estadistica, Santiago.

Smith, E. A. 1875. Description of a new species of Solenella from south Patagonia.

Annals and Magazine of Natural History. Series 4 16: 118-119.

— 1881. Account of the zoological collections made during the survey of H. M. S.

‘Alert’ in the Straits of Magellan and on the coast of Patagonia. IV. Mollusca and

Molluscoida. Proceedings of the Zoological Society of London 1881: 22-44.

Smith, J. T. 1970. Taxonomy, distribution, and phylogeny of the cymatiid gastropods

Argobuccinum, Fusitriton, Mediargo, and Priene. Bulletins of American Paleontology

56: 445-574.

Soot-Ryen, T. 1955. A report on the family Mytilidae (Pelecypoda). Allan Hancock

Pacific Expeditions 20: 1-174.

— 1959. Reports of the Lund University Chile Expedition 1948-49. 35. Pelecypoda.

Lunds Universitets Arsskrift. N. F. Avd. 2 55(6): 1-86.

Sowerby, G. B. 1833a. A catalogue of recent species of Nuculae. pp. 3-6. In: Sowerby,

G. B. (ed.) The Conchological Illustrations Part 14. Sowerby, London.

— 1833b. New species of shells collected by Mr. Cuming on the western coast of

South America, and among the islands of the South Pacific Ocean. Proceedings of

the Zoological Society of London 1833: 34-38.

—— 1834. New species of shells contained in the collection formed by Mr. Cuming on

the western coast of South America, and among the islands of the South Pacific

Ocean. Proceedings of the Zoological Society of London 1834: 87-89.

— 1835. Shells collected by Mr. Cuming on the western coast of South America, and

among the islands of the South Pacific Ocean . . . undescribed species of the genus

Fissurella. Proceedings of the Zoological Society of London 1834: 123-128.

—— 1838. A descriptive catalogue of the species of Leach’s genus Margarita.

Malacological and Conchological Magazine 1: 23-27.

1840. Description of some new chitons. Magazine of Natural History (new series)

4: 287-294.

1874. Monograph of the genus Chilina. In: Reeve, L. A. (ed.) Conchologia

Iconica, L. A. Reeve, London.

Spalowsky, J. J. N. A. 1795. Prodromus in Systema Historicum Testaceorum. Wien.

D.G. REID AND C. OSORIO

Stempell, W. 1899. Die Muscheln der Sammlung Plate. Zoologische Jahrbiicher.

Supplementband 5: 217-250.

Stotz, W. B. 1981. Aspectos ecoldgicos de Mytilus edulis chilensis (Hupé, 1854) en el

estuario del rio Lingue (Valdivia, Chile). Revista de Biologia Marina 17: 335-377.

Strebel, H. 1904. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz.

I. Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der

Tiere 21: 171-248.

1905a. Beitraége zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. II. Die

Trochiden. Zoologische Jahrbiicher. Supplement 8: 121-166.

— 1905b. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. No. 3.

Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der

Tiere 22: 575-666.

1906. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. No. 4.

Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der

Tiere 24: 91-174.

—— 1907. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. No. 5.

Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der

Tiere 25: 79-196.

Stuardo, J. 1961. Contribucion a un catélogo de los moluscos gaster6podos Chilenos

de agua dulce. Gayana. Zoologia 1: 1-32.

— 1964. Distribucion de los moluscos marinos litorales en latinoamerica. Boletin del

Instituto de Biologia Marina. Mar del Plata 7: 79-91.

— 1979. Sobre la clasificacion, distribucion y variacion de Concholepas concholepas

(Bruguiére, 1789): un estudio de taxonomia beta. Biologia Pesquera 12: 5-38.

Suchanek, T. H. 1985. Mussels and their rdle in structuring rocky shore communities.

pp. 70-96. In: Moore, P. G. & Seed, R. (eds) The Ecology of Rocky Coasts. Hodder

& Stoughton, London.

Taylor, J. D. & Smythe, K. R. 1985. A new species of Trochita (Gastropoda:

Calyptraeidae) from Oman: a relict distribution and association with upwelling

areas. Journal of Conchology 32: 39-48.

Thompson, T. E. & Brown, G. H. 1984. Biology of Opisthobranch Molluscs 2. 229 p.

Ray Society, London.

Thore, S. 1959. Reports of the Lund University Chile Expedition 1948-49. 33.

Cephalopoda. Lunds Universitets Arsskrift N. F. Avd. 2 55 (1): 1-19.

Turner, R. D. 1966. A Survey and Illustrated Catalogue of the Teredinidae (Mollusca:

Bivalvia). 265 p. Museum of Comparative Zoology, Harvard University, Cambridge,

Mass.

Ubaldi, R. 1985. A contribution to the knowledge of genus Nacella Schumacher, 1817

in the Antarctic and Sub-Antarctic regions. (Part 1). Argonauta 1: 10-22.

Urban, H.-J. 1994. Adaptations of six infaunal bivalve species of Chile: coexistence

resulting from differences in morphology, burrowing depth and substrate preference.

Archive of Fishery and Marine Research 42: 183-193.

—— 1996. Population dynamics of the bivalves Venus antiqua, Tagelus dombeii, and

Ensis macha from Chile at 36°S. Journal of Shellfish Research 15: 719-727.

Urban, H.-J. & Tesch, C. 1996. Aspects of the population dynamics of six bivalve

species from southern Chile. Results of the “Victor Hensen’ cruise to the Magellan

Strait and the Beagle Channel in October/November 1994. Archive of Fishery and

Marine Research 44: 243-256.

Valdovinos, C. & Stuardo, J. 1995. Morfologia funcional de Chilina angusta (Philippi,

1860), y evolucién de Chilinidae. Resumos, II Congresso Latino-Americano de

Malacologia, Porto Alegre, Brasil: 43.

Vermeij, G. J. 1993. Spinucella, a new genus of Miocene to Pleistocene muricid

gastropods from the eastern Atlantic. Contributions to Tertiary and Quaternary

Geology 30: 19-27.

Villarroel, M. & Stuardo, J. 1998. Protobranchia (Mollusca: Bivalvia) chilenos

recientes y algunos fosiles. Malacologia 40: 113-229.

Viviani, C. A. 1979. Ecogeographia del litoral chileno. Studies on Neotropical Fauna

and Environment 14: 65-123.

Waller, T. R. 1991. Evolutionary relationships among commercial scallops (Mollusca:

Bivalvia: Pectinidae). pp. 1-73. In: Shumway, S. E. (ed.) Scallops: Biology, Ecology

and Aquaculture. Elsevier, Amsterdam.

Waloszek, D. 1984. Variabilitat, Taxonomie und Verbreitung von Chlamys patagonica

(King & Broderip, 1832) und Anmerkungen zu weiteren Chlamys-Arten von der

Siidspitze Siid-Amerikas (Mollusca, Bivalvia, Pectinidae). Verhandlungen des

Naturwissenschaftlichen Vereins in Hamburg 27: 207-276.

Waloszek, D. & Waloszek, G. 1986. Ergebnisse der Forschungsreisen des FFS

“Walther Herwig’ nach Siidamerika. LXV. Vorkommen, Reproduktion, Wachstum

und mégliche Nutzbarkeit von Chlamys patagonica (King & Broderip, 1832)

(Bivalvia, Pectinidae) auf dem Schelf vor Argentinien. Archiv fiir

Fischereiwissenschaft 37: 69-99.

Watson, R. B. 1886. Report on the Scaphopoda and Gasteropoda collected by H.M.S.

Challenger during the years 1873-76. Report on the Scientific Results of the Voyage

of H.M.S. Challenger During the Years 1873-76. Zoology 15: 1-756.

Weaver, C. S. & duPont, J. E. 1970. Living Volutes. 375 p. Delaware Museum of

Natural History, Greenville, Delaware.

Wu, S.-K. 1985. The genus Acanthina (Gastropoda: Muricacea) in west America.

Special Publication of the Mukaishima Marine Biological Station 1985: 45-66.

Bull. nat. Hist. Mus. Lond. (Zool.) 66(2): 147-166

Issued 30 November 2000

Remarks on the genera Schizocuma Bacescu,

1972 and Styloptocuma Bacescu & Muradian,

1974 (Crustacea, Cumacea)

SEE tal 3G

I, PETRESCU

Department of Invertebrates, ‘Grigore Antipa’ National Museum of Natural History, Kiseleff l, Bucharest

79744, Romania.

SYNOPSIS. Morphological data are presented to support the view that Schizocuma Bacescu, 1972 and Styloptocuma Bacescu &

Muradian, 1974 are good genera. Both genera exhibited a mixture of characters found in Cumella and Nannastacus, but share

more common with Cumella. Schizocuma and Styloptocuma appeared to have evolved in deeper waters, earlier than the rest of

Cumella group, having separated from a common stem with the Nannastacus group.

INTRODUCTION

Schizocuma Bacescu and Styloptocuma Bacescu & Muradian are

two deep-sea genera belonging to the family Nannastacidae. Cur-

rently available descriptions of the species in these genera are

incomplete, lacking data on the mouthparts or one of the sexes. In

the case of Schizocuma vemae, (known only from the holotype), the

type material has been lost. Both Schizocuma and Styloptocuma

have been subjects of systematic revisions by authors who have

either totally or partially invalidated them (Jones 1984, Watling

1991), or considered them to be good genera (Bacescu 1992, Holt-

huis 1990).

This study is based entirely on material loaned to the author by the

Department of Zoology of the Natural History Museum, London.

MATERIALS AND METHODS

The material examined consists of non type specimens of 8 species,

7 of which were described by Jones (1984); all were previously

identified by him and included in the genus Cumella. These speci-

mens were collected by different research vessels of Woods Hole

Oceanographic Institute.

Cumella acuminatum Jones, 1984 1992:700:30

86 specimens (females and immature males); collecting data —

Atlantis II 31, sta.156, 0° 46' S 29° 28' W, 3459 m, 14.2.1967.

Cumella antipai (Bacescu & Muradian, 1974) 1992:678:10

13 females, 3 males (2 adults and 1 immature); collecting data —

Knorr 25, sta.293, 8° 58' N 50° 04.3' W, 1518 m, 27.2.1972.

Cumella bishopi Jones, 1984 1992:677:30

44 females, 38 males (22 adults and 16 immatures); collecting data

— Knorr 25, sta.293, 8° 58' N 50° 04.3' W, 1518 m, 27.2.1972.

Cumella dayae Jones, 1984 1992:684:36

22 females, 17 males (5 adults and 12 immatures); collecting data —

Atlantis II 60, sta. 245, 36° 35.7’ S 53° O1' W, 2707 m, 14.3.1971.

Cumella echinata Jones, 1984 1992:685:20

18 females, 4 males; collecting data — Chain 106, sta. 313, 51° 32.2'

N 12° 35.9' W, 1500 m, 17.8.1972.

Cumella formosa Jones, 1984 1992:676:4

3 females, 1 immature male, 1 manca; collecting data — Atlantis II

60, sta. 245, 36° 55.7' S 53° 61.4' W, 2707 m, 14.3.1971.

Cumella spinoculata Jones, 1984 1992:783:7

3 females, 2 males and 2 juv.; collecting data — Chain 106, sta. 313,

ple 32-2) N22 35.9 W500 im, 172821972:

Cumella vemae (Bacescu & Muradian, 1974) 1992:777:4

1 female, 2 immature males; collecting data— Atlantis II 31, sta.167,

7°58 S945 07 W: 1007 mi; 20.2.1967.

13 specimens in glycerine-alcohol on slides were dissected for

this study. Measurements were taken with an ocular micrometer, and

all the slides are deposited in the collections of the Natural History

Museum, London.

SYSTEMATIC REMARKS

Genus SCHIZOCUMA Biacescu, 1972

Schizocuma Bacescu, 1972: 246.

Cumella Jones, 1984: 210-211.

Schizocuma Watling, 1991: 755.

Schizocuma Bacescu, 1992: 258-259.

TYPE SPECIES. Schizocuma vemae Bacescu, 1972.

DIAGNOSIS. Carapace short (one-fifth the length of pleon with

uropods), without carinae, with long hairs in males and dorsal spines

in females (also on the ocular lobe); antero-ventral corner rounded

or subacute, antero- inferior edge slightly serrated. Median ocular

lobe incompletely subdivided. Branchial siphons separated, located

medially to dorsolaterally; pseudorostral lobes widely separated.

Pleonites long and thin, their length increasing distally up to the

fifth, which is 5.5 times longer than broad. Pleotelson short. An-

tenna | without tubercle on 2™ article of peduncle, subequal in

length or longer than 3", accessory flagellum 2-articulated. Antenna

2 with short flagellum. Pars incisiva of mandible with 4 teeth, lacinia

mobilis, thin, with 3 teeth, not exceeding pars incisiva, five long

plumose lifting setae between lacinia mobilis and truncated, robust,

pars molaris. Maxilla 1 with simple robust acuminate setae on

148

I. PETRESCU

Fig. 1 Schizocuma spinoculatum (Jones, 1984) immature male A. antenna 1; B. antenna 2; C. mandible; D. maxilla 1; E. maxilla 2; F. maxilliped 1; G.

maxillipd 2. Scale bars (in mm): A 0.1; B 0.2; C-F 0.1; G 0.1.

nea on

SCHIZOCUMA AND STYLOPTOCUMA

149

Fig. 2 Schizocuma spinoculatum (Jones, 1984) A-E. immature male; F, G. female A. maxilliped 3; B. pereopod 1; C. pereopod 2; D. pereopod 3; E.

uropod; F. maxilliped 3; G. pereopod 1. Scale bars (in mm): A, E 0.1; B, C, F, G 0.2; D 0.2.

150

protopod, palp with 2 filaments. Maxilla 2 with two endites, fine

simple setae on endites and outer margins of protopod. Basis of

maxilliped 1 with an outer endite not exceeding merus, carpus with

flattened hand-like setae on outer margin of carpus, rounded, en-

larged dactylus. Basis of maxilliped 2, longest article, merus bulky,

carpus longer than all articles excepting basis, with short plumose

setae on outer margin, dactylus with an apical claw. Maxilliped 3

with short inner process. Exopods on maxilliped 3 and pereopods 1—

2 in females and on maxilliped 3 and pereopods 1-4 in males.

Uropod peduncle much longer than pleonite 6 and its rami, uropod

exopod basal article normal, endopod as long as, or slightly longer

than exopod.

GENDER. Neuter.

ADDITIONAL SPECIES. Schizocuma calmani (Stebbing, 1912), S.

molossa (Zimmer, 1907), S. spinoculatum (Jones, 1984), S. spinosum

(Jones, 1984).

REMARKS. Bacescu (1972) considered Schizocuma to be distin-

guishable from Cumella only by the separated siphons and

slenderness and elongation of the body and appendages. Jones

(1984) argued that there is a gradation in body and appendage form

and there are not sufficient criteria to recognise Schizocuma as a

separate genus. Watling (1991) added to the characters presented by

Bacescu, including dorso-lateral pseudorostral lobes and unique

ocular lobe, and considered Schizocuma as a valid genus. The study

of the mandible and maxilliped 1 revealed that there are also

distinctive characters that clearly separate Schizocuma from Cumella:

pars incisiva of mandible with 4 teeth (versus 3 in Cumella),

dactylus of maxilliped 1 rounded and enlarged versus acuminate and

small in Cumella. These last characters and the separated

pseudorostral lobes and siphons are more similar to the Nannastacus

group (Nannastacus, Scherocumella, Schizotrema), but the others

(unique eye lobe, peduncle of antenna | without tubercle, maxilliped

2 with slender plumose setae on propodus, uropods with long

peduncles) are more like Cumella. Watling (1991) mentioned in the

list of the additional species of this genus the species Schizocuma

divisa (Jones, 1984). In my opinion this species belongs to the genus

Cumella (as described by Jones) because of its non-separated si-

phons, fairly short pleon and a uropodal peduncle 1.5 longer than its

rami (shorter than in Schizocuma).

Schizocuma spinoculatum (Jones, 1984)

Figs 1, 2

Cumella spinoculata Jones, 1984: 219-220.

Schizocuma spinoculata Watling, 1991: 755.

Schizocuma spinoculatum Bacescu, 1992: 258-259.

DESCRIPTION. To the original description I am adding add the

following morphological data on the immature male (not mentioned

by Jones). Antenna | (Fig. 1 A) with spine on 1“ article of peduncle,

2™ article a little longer than 3", accessory flagellum 2-articulate.

Antenna 2 (Fig. | B) characteristic for an older stage, with short

flagellum, but most articles well developed. Mandible (Fig. 1 C),

pars incisiva with 4 teeth, lacinia mobilis with 3 teeth, robust pars

molaris with a tooth-like process on its distal outer corner. Maxilla

1 (Fig. 1 D), protopod with 9 acuminate setae, palp with 2 unequal

filaments, the longest backwardly setulated in its- proximal half.

Maxilla 2 (Fig. 1 E) with simple setae on endites that exceed

protopod and margins of protopod. Maxilliped 1 (Fig. 1 F), with

endite of basis not exceeding extremity of merus, with strong

plumose setae, acuminate setae and retinacula; flattened hand-like

setae on outer margin of carpus, with rounded extremity; propodus

I. PETRESCU

a little longer than dactylus (propodus/dactylus= 1.4), rounded and

enlarged dactylus with few apical setae. Maxilliped 2 (Fig. 1 G),

basis a third of the entire maxilliped, bulky merus, carpus, the

longest article excepting basis, propodus with plumose setae on

outer distal corner, dactylus as long as his strong claw. Maxilliped 3

(Fig. 2 A), basis, stronger than in female, with a very short inner

process. Pereopod 1 (Fig. 2 B), basis without spines as in female,

carpus as long as propodus. Pereopod 2 (Fig. 2 C), with stronger

basis, a stiff acuminate seta on outer distal corner of carpus (fine,

simple setae in female), dactylus a little longer than in female

(dactylus/propodus= 2.5). Pereopod 3 (Fig. 2 D), basis longer than

half of pereopod, dactylus with long terminal seta. Uropod (Fig. 2 E),

peduncle much longer than last pleonite (1.85) and its rami (1.80),

exopod a little shorter than endopod, with a terminal seta, endopod

with 4 short setae on inner margin and a terminal robust short one.

Jones (1984) description of the female is amended to include the

following details: Maxilliped 3 (Fig. 2 F), basis with short inner

process, merus also without any process, a little longer than dacty-

lus, dactylus with an apical, strong, claw, longer than the article.

Pereopod | (Fig. 2 G), basis shorter than half of the entire pereopod,

2 acuminate setae on distal outer corner, carpus shorter than propodus,

dactylus with a claw longer than it. Pereopod 2 (Fig. 2 G), basis

shorter than half of the entire pereopod, dactylus 2.4 times longer

than propodus, with short simple terminal setae.

Schizocuma vemae Bacescu, 1972

Figs 3, 4

Schizocuma vemae, Bacescu, 1972: 246.

Cumella vemae, Jones, 1984: 214

Schizocuma vemae, Watling, 1991: 755

Schizocuma vemae, Bacescu, 1992: 258-259.

DESCRIPTION. To the description of the female in Jones (1984) the

following additional observations: Carapace (Fig. 3 A) with one

dorsal spine (up to 4 in Jones). Pereopod | (Fig. 3 B), basis shorter

than half of entire pereopod, carpus a little shorter than propodus,

dactylus shorter than its claw. Pereopod 2 (Fig. 3 C), basis shorter

than half of entire pereopod, a stiff acuminate seta on outer distal

corner of carpus as long as propodus, dactylus 4.3 times longer than

propodus, with simple setae. Pereopod 3 (Fig. 3 D), with thin and

long articles, basis as long as half of entire pereopod, carpus 3.2

times longer than propodus, dactylus with a long terminal seta.

Uropod (Fig. 3 E), peduncle very long (4 times longer than last

pleonite), peduncle/rami = 2.5; exopod as long as endopod, with a

terminal seta, endopod with simple setae and subterminal acuminate

seta on inner margin and a terminal, thin acuminate seta.

The description of an immature male by Bacescu (1972) was also

incomplete. The following details are added: Antenna 1 (Fig. 3 F),

peduncle articles long and thin, 2™ article longer than 3", accessory

flagellum, 2-articulate, shorter than basal article of main flagellum.

Antenna 2 (Fig. 3 G), characteristic of an immature male. Mandible

(Fig. 3 H), pars incisiva with 4 teeth, lacinia mobilis with 3 teeth,

robust, truncated pars molaris with a tooth-like process. Maxilla 1

(Fig. 4 A), protopod with 9 acuminate setae, palp with 2 unequal

filaments, the longest one is backwardly setulated. Maxilla 2 (Fig. 4

B), as usual for the genus. Maxilliped 1 (Fig. 4 C), carpus with

flattened hand-like setae with acute extremity, propodus 3.3 times

longer than dactylus, dactylus with apical fine, small setae. Maxilliped

2 (Fig. 4 D), with robust articles, as is usual for the genus. Pereopod

3 (Fig. 4 E), carpus 2.5 times longer than propodus, dactylus with a

long, curved acuminate seta. Pereopod 4 (Fig. 4 F), basis thinner,

carpus longer than in the previous pair (3 times longer), dactylus

SCHIZOCUMA AND STYLOPTOCUMA

Se ws

Fig. 3 Schizocuma vemae Bacescu, 1972 A-E. female; F—H. immature male A. body, lateral view; B. pereopod 1; C. pereopod 2; D. pereopod 3; E.

uropod; F. antenna 1; G. antenna 2; H. mandible. Scale bars (in mm): A 1; B 0.25; C, D 0.3: E 0.3: F, G0.2:H0.1.

151

152 I. PETRESCU

Fig. 4 Schizocuma vemae Bacescu, 1972 immature male A. maxilla 1; B. maxilla 2; C. maxilliped 1; D. maxilliped 2; E. pereopod 3; F. pereopod 4; G.

pereopod 5; H. uropod. Scale bars (in mm): A—D 0.1; E—G 0.2; H 0.3.

SCHIZOCUMA AND STYLOPTOCUMA

also with a terminal, long, curved acuminate seta. Pereopod 5 (Fig.

4 G), basis as long as half of entire pereopod, carpus about 2 times

longer than propodus. Uropod (Fig. 4 H), peduncle shorter than in

female (2:1), 2 times longer than its rami, exopod as long as

endopod, with a long terminal seta, endopod with a subterminal long

simple seta and a terminal acuminate seta.

REMARKS. It does not seem possible to establish a neotype for the

species because the specimens from the British collection, although

from the same deep western Atlantic, are far (7° 58' S 34° 17' W)

from the type locality (27° 7' N 77° 08' W).

Key for the identification of Schizocuma species

iS pines Omicarapace and CYEe 1ODE....,....--..c.cc.-ssescercsncsesenceeseacenseereenvases 2

MESON CalapAace OF OM CVE LODE: ...<....c.cnncears<0-ceeadeccevsnsestonevaceonoweses 4

2 Dorsal spines on the whole carapace ...........:::sccssssesseescssescenseaeeseeeeees 3

— Dorsal spines only on the posterior part of carapace ............::.cceeeeeee

OUR cris ante ascohsensaus asszsevedsedeusesesnceswovsete S. molossa (Zimmer, 1913)

3 Double rows of spines on carapace ............ S. spinosum (Jones, 1984)

— Single row of spines on carapace ............ S. calmani (Stebbing, 1912)

4 __ Spines only on eye lobe ..............:::ee S. spinoculatum (Jones, 1984)

=P SPINES ONLY OM CaraPaCe ...........00-seeceeeeceesencees S. vemae Bacescu, 1972

Genus STYLOPTOCUMA Bacescu & Muradian, 1974

Styloptocuma Bacescu & Muradian, 1974: 74-75.

Cumella Ledoyer, 1983: 77.

Cumella Jones, 1984: 210-211.

Cumella (Styloptocuma) Watling, 1991: 752

Styloptocuma Bacescu, 1992: 262-265.

Styloptocuma Holthuis, 1992: 264.

Cumella Ledoyer, 1997: 869 — 876.

TYPE SPECIES. S. antipai Bacescu & Muradian, 1974.

DIAGNOSIS. Very elongate cumacean, with numerous spines on

entire body or only on carapace, long upturned pseudorostrum, long,

styliform eye lobe that could reach or even exceed the extremity of

pseudorostrum, without any traces of visual elements. Antenna |

with a very long basal peduncle article (longer than half of pedun-

cle), second article with a tubercle, main flagellum with two long

articles, accessory flagellum with two articles, shorter than the first

article of main flagellum. Pars incisiva of mandible with 4 teeth,

lacinia mobilis with 4 (rarely 3) teeth, long stiff setae between

lacinia mobilis and robust pars molaris (without any tubercles).

Maxilla 1 with robust acuminate setae on protopod, palp with 2

filaments. Maxilla 2 with endites, possibly with a row of fine, small

setae between the outer margin of protopod and endites. Maxilliped

1 with basis never exceeding extremity of merus, carpus with hand-

like setae on outer margin, long propodus and rounded dactylus.

Maxilliped 2 with long and slender basis, propodus with two plumose

setae on distal outer corner, dactylus with terminal setae. Maxilliped

3 without inner process of basis, propodus longest article excepting

basis, dactylus with terminal claws or setae. Pereopods and uropods

very slender. Number of exopods — 3 in female, 5 in male.

GENDER. Neuter.

ADDITIONAL SPECIES. S. aculeatum (Jones, 1984), S$. acuminatum

(Jones, 1984), S. angustatum (Jones, 1984), S. concinnum (Jones,

1984), S. bishopi (Jones, 1984), S. cristatum (Jones, 1984), S. dayae

153

(Jones, 1984), S. echinatum (Jones, 1984), S. egregium (Hansen,

1920), S. erectum (Jones, 1984), S. extans (Jones, 1984), S. formosum

(Jones, 1984), S. gracillimum (Calman, 1905), S. inermis (Ledoyer,

1997), S. longisipho (Jones, 1984), S. subductum (Jones, 1984).

REMARKS. Jones (1984) considered Styloptocuma to be a syno-

nym of Cumella because there did not seem to be any characters that

could be used to separate the genus (pseudorostrum, eye lobe, form

of body, antennule, pereopods and uropods). The absence of

mouthparts, especially maxilliped 1, from the descriptions, and no

importance accorded to the tubercle on the antennule, also caused

Ledoyer (1983, 1997) to adopt Jones’ view. In his revision of some

genera of nannastacids based on earlier descriptions, Watling 1991

concluded that Styloptocuma could be considered a subgenus of

Cumella. Holthuis (1992) discussed only the designation of the type

species of this genus and accepted the concept of Styloptocuma in

Bacescu & Muradian (1974) without any further comment.

Styloptocuma possesses a mixture of characters that unite it with

most of the Cumella group — non-separated pseudorostral lobes, a

unique eye lobe, form of carapace, lacinia mobilis of mandible with

3 teeth, propodus of maxilliped 2 with setae, thin pereopods, long

uropods; and to the Nannastacus group — antenna | with tubercle,

mandible with 4 teeth on pars incisiva and lacinia mobilis, long,

rounded dactylus of maxilliped 1. Maxilla 2 has features of both

groups (the transeverse row of setules on the protopod is character-

istic for the Nannastacus group; absent in Cumella). This genus

seems to link these groups and therefore has a unique set of characters.

Styloptocuma acuminatum (Jones, 1984)

Figs 5,6

Cumella acuminata Jones, 1984: 220-221.

Cumella (Styloptocuma) acuminata Watling, 1991: 752.

Styloptocuma acuminatum Bacescu, 1992: 262.

DESCRIPTION. A brief description of the distinctive characters of

the immature male not mentioned by Jones is given. Antenna 2 as in

Fig. 5 B. Maxilliped 3 (Fig. 5 C) has a longer basis and dactylar claw

than in the female. Pereopod | (Fig. 5 D) with an acuminate seta on

outer distal corner of basis. Pereopod 2 (Fig. 5 E) with teeth on outer

margin of basis and a shorter dactylus (shorter than carpus). Pereopods

3 and 4 (Fig. 5 F, G) with exopods, carpus longest article of pereopod

excepting basis, dactylus with a long curved terminal seta. Pereopod

5 (Fig. 5 H) with the shortest basis of all pereopods, carpus shorter

than in pairs 3 and 4. Uropod (Fig. 5 I) with peduncle 1.2 longer than

the last pleonite and 1.8 times longer than its rami; subequal rami,

exopod with a terminal short acuminate seta, endopod with 5 slender

acuminate setae on inner margin and a short terminal robust acumi-

nate seta.

To the description of female in Jones (1984) the following details

are added: Antenna | (Fig. 5 J, K) with a tubercle on the 2™ article

of the peduncle. Mandible (Fig. 5 L), pars incisiva with 4 teeth,

lacinia mobilis with 4 teeth (one of them very small), truncated pars

molaris. Maxilla 1 (Fig. 6 A) with robust acuminate setae on

protopod and palp with 2 filaments, the longest being backwardly

setulated in its proximal half. Maxilla 2 (Fig. 6 B) without a row of

fine, small setae between endites and outer margin of protopod.

Maxilliped 1 (Fig. 6 C) with a bifid robust acuminate seta on endite

of basis, carpus with hand-like flattened setae with 6 denticles,

dactylus smaller than propodus, enlarged, with excavated distal

margin. Maxilliped 2 (Fig. 6 D), slender basis, carpus longest article

excepting basis, propodus with plumose setae, dactylus with a

curved claw. Maxilliped 3 (Fig. 6 E), basis without inner process,

dactylus with terminal setae. Pereopod 3 (Fig. 6 H), with slender

154 I. PETRESCU

Fig.5 — Styloptocuma acuminatum (Jones, 1984) A-I. immature male; J — L. female A. body, lateral view; B. antenna 2; C. maxilliped 3; D. pereopod 1; E.

pereopod 2; F. pereopod 3; G. pereopod 4; H. pereopod 5; I. uropod; J. antenna 1; K. antenna 1, detail; L. mandible. Scale bars (in mm): A 0.5; B, D-J

O2ZAC OW AKON OL05:

SCHIZOCUMA AND STYLOPTOCUMA

155

Fig. 6 Styloptocuma acuminatum (Jones, 1984) female A. maxilla 1; B. maxilla 2; C. maxilliped 1; D. maxilliped 2; E. maxilliped 3; F. pereopod 1; G.

pereopod 2; H. pereopod 3; I. pereopod 4; J. pereopod 5. Scale bars (in mm): A 0.1; B—D 0.05; E—J 0.2.

156

articles, basis shorter than half of pereopod, carpus longest article

of pereopod excepting basis, dactylus with a long curved apical seta.

Pereopod 4 (Fig. 6 I), similar to the previous pair. Pereopod 5 (Fig.

6 J) with the smallest basis of all pereopods and with carpus longer

than in the pairs 3 and 5.

REMARKS. Pereopod | (Fig. 6 F) has a basis with two teeth on

outer margin (absent in description given in Jones 1984). Pereopod

2 (Fig. 6 G) has a shorter dactylus than is suggested in the original

description.

Styloptocuma antipai Bacescu & Muradian, 1974

Fig. 7

Styloptocuma antipai Bacescu & Muradian, 1974: 74-75.

Cumella antipai Jones, 1984: 214.

Cumella (Styloptocuma) antipai Watling, 1991: 752

Styloptocuma antipai Bacescu, 1992: 262.

DESCRIPTION. The description of an immature male including the

mouth appendages is given. Mandible (Fig. 7 A) as in S. acuminatum.

Maxilla 1 (Fig. 7 B) with glabrous filaments. Maxilla 2 (Fig. 7 C) as

in S. acuminatum. Maxilliped 1 (Fig. 7 D) with hand-like flattened

setae on carpus (different form than in S. acuminatum), rounded and

enlarged dactylus. Maxilliped 3 (Fig. 7 E) as in female described by

Bacescu & Muradian (1974). Pereopod 1 (Fig. 7 F), with carpus as

long as propodus instead of carpus shorter than propodus of female

(as given in Bacescu & Muradian 1974 and Jones 1984). Pereopod

2 (Fig. 7 G), as in female, but with glabrous margins of basis and

dactylus with a shorter terminal seta. Pereopod 3 (Fig. 7 H), basis

half of pereopod, dactylus with a terminal strong curved claw.

Pereopods 1-4 with exopods. Uropod (Fig. 7 I), peduncle 2 times

longer than the last pleonite, 1.5 times longer than its rami, inner

margin serrated; subequal rami, exopod with simple setae on both

margins and a long terminal one, endopod with three acuminate

setae on inner margin and a terminal robust acuminate seta a little

shorter than on exopod.

Styloptocuma bishopi (Jones, 1984)

Figs 8, 9

Cumella bishopi Jones, 1984: 233.

Cumella (Styloptocuma) bishopi Watling, 1991: 752

Styloptocuma bishopi Bacescu, 1992: 263.

DESCRIPTION. A description of immature male is given. Antenna

1 (Fig. 8 A), 1“ article of peduncle shorter than remaining articles,

2™ article with a tubercle with pedunculate setae. Mandible (Fig. 8

B), pars incisiva with 4 teeth, robust lacinia mobilis with 3 teeth,

truncated pars molaris. Maxilla 1 (Fig. 8 C), as in S. antipai, with

glabrous filaments. Maxilla 2 (Fig. 8 D), with a row of fine, small

setae between endites and outer margin of protopod. Maxilliped 1

(Fig. 8 E), endite of basis with 2 spatulate setae, carpus with hand-

like flattened setae with 6 denticles, rounded dactylus. Maxilliped 2

(Fig. 8 F), as usual for the genus. Maxilliped 3 (Fig. 8 G), basis and

merus without teeth. Pereopod 1 (Fig. 8 H), as in female. Pereopod

2 (Fig. 8 I), as in female, with larger basis. Pereopod 3 (Fig. 9 A),

basis half of pereopod, carpus 2 times longer than propodus. Pereopod

4 (Fig. 9 B), basis shorter than half of pereopod, carpus 3 times

longer than propodus. Pereopod 5 (Fig. 9 C), slender articles, carpus

3.8 times longer than propodus.

The description in Jones (1984) is augmented with the following

details: Pereopod 3 (Fig. 9 G), basis half of pereopod, with serrated

outer margin, carpus/propodus = 1.6, dactylus with a short curved

I. PETRESCU

claw. Pereopod 4 (Fig. 9 H), basis shorter than half of pereopod, with

a serrated outer margin, longer carpus (carpus/propodus = 2.5).

Pereopod 5 (Fig. 9 I), basis shorter than half of pereopod, with

serrated outer margin, carpus longer than in the pairs 3 and 4 (carpus

/propodus= 2.8).

REMARKS. Differences noted in specimens examined for this study

include: maxilliped 3 (Fig. 9 D) with a tooth on inner margin of

merus, pereopod 1 (Fig. 9 E) with teeth also on the outer margin,

carpus longer than propodus (versus carpus shorter than propodus),

pereopod 2 (Fig. 9 F), with 2 stiff acuminate setae on outer distal

corner of carpus (instead of simple setae).

Styloptocuma dayae (Jones, 1984)

Figs 10, 11

Cumella dayae Jones, 1984: 226-227.

Cumella (Styloptocuma) dayae Watling, 1991: 752.

Styloptocuma dayae Bacescu, 1992: 263

DESCRIPTION. The description of the female is supplemented with

additional data on antenna 1, mouthpieces and maxillipeds 1, 2 and

pereopods 3-5. Antenna | (Fig. 10 A), 2™ article of peduncle with a

short tubercle. Mandible (Fig. 10 B), pars incisiva with 4 teeth (one

of them is very short), strong lacinia mobilis with 3 teeth. Maxilla 1

(Fig. 10 C), protopod with robust acuminate setae and palp with 2

glabrous filaments. Maxilla 2 (Fig. 10 D), no row of fine, small setae

between endites and outer margin of protopod. Maxilliped 1 (Fig. 10

E), carpus with hand-like flattened setae with 4 denticles, rounded

and enlarged dactylus. Maxilliped 2 (Fig. 10 F), as usual for the

genus. Pereopod 3 (Fig. 10 G), basis longer than half of pereopod,

tiny dactylus with a long terminal seta. Pereopod 4 (Fig. 10 H), basis

shorter than half of pereopod, carpus shorter than in the previous

pair. Pereopod 5 (Fig. 10 I), basis shorter than half of pereopod,

carpus longer than in pairs 3 and 4.

Some details on the structure of the immature male are also

provided. Maxilliped 3 (Fig. 11 A), basis without the short process

mentioned by Jones for the female. Pereopods | and 2 (Fig. 11 B, C),

as in female. Pereopod 3 (Fig. 11 D), basis half of pereopod, carpus/

propodus: 1.8, tiny dactylus with long terminal seta. Pereopod 4

(Fig. 11 E), basis shorter than half of pereopod, carpus/propodus:

1.7. Pereopod 5 (Fig. 11 F), basis shorter than carpus, carpus/

propodus: 3.1.

Styloptocuma echinatum (Jones, 1984)

Figs 12, 13

Cumella echinata Jones, 1984; 223-224.

Cumella (Styloptocuma) echinata Watling, 1991: 752.

Styloptocuma echinatum Bacescu, 1992: 263.

DESCRIPTION. This species was incompletely described in Jones

(1984), his description being based only the female. Additional

details for immature males and females are included here. Jmmature

male — Antenna | (Fig. 12 A), 1“ article of peduncle twice longer

than the rest of antenna, 2" article with a tubercle. Mandible (Fig. 13

B), pars incisiva with 4 teeth, lacinia mobilis also with 4 teeth (one

of them very short). Maxilla 1 (Fig. 13 C), palp with 2 glabrous

filaments. Maxilla 2 (Fig. 13 D), long fine setae on outer margin of

protopod, but not between its outer margin and endites. Maxilliped

1 (Fig. 13 E), carpus with hand-like flattened setae with 4 denticles,

rounded and enlarged dactylus. Maxilliped 2 (Fig. 13 F), as usual for

the genus. Maxilliped 3 (Fig. 13 G), basis without inner process,

dactylus with 2 claws. Pereopod 1 (Fig. 13 H), basis with rows of

SCHIZOCUMA AND STYLOPTOCUMA 157

Fig. 7 Styloptocuma antipai Bacescu & Muradian, 1974 immature male A. mandible; B. maxilla 1; C. maxilla 2; D. tip of maxilliped 1; E. maxilliped 3; F.

pereopod 1; G. pereopod 2; H. pereopod 3; I. uropod. Scale bars (in mm): A — D 0.05; E—H 0.1; 10.2.

158

I. PETRESCU

SE.

Fig. 8 Styloptocuma bishopi (Jones, 1984) immature male A. antenna 1; B. mandible; C. maxilla 1; D. maxilla 2; E. maxilliped 1; F. maxilliped 2; G.

maxilliped 3; H. pereopod 1; I. pereopod 2. Scale bars (in mm): A 0.1; B—E 0.05; F 0.1; G—10.2.

SCHIZOCUMA AND STYLOPTOCUMA

Fig.9 Styloptocuma bishopi (Jones, 1984) A — C. immature male; D —I. female A. pereopod 3; B. pereopod 4; C. pereopod 5; D. maxilliped 3; E.

pereopod 1; F. pereopod 2; G. pereopod 3. H. pereopod 4; I. pereopod 5. Scale bars (in mm): A —C, E, F—1 0.2; D 0.2.

160

I. PETRESCU

Fig. 10 Styloptocuma dayae (Jones, 1984) female A. antenna 1; B. mandible; C. maxilla 1; D. maxilla 2; E. maxilliped 1; F. maxilliped 2; G. pereopod 3;

H. pereopod 4: I. pereopod 5. Scale bars (in mm): A 0.2; B, E 0.05; C, D 0.05; F 0.1.

teeth on both margins, very long and slender carpus and propodus,

carpus a little longer than propodus. Pereopod 2 (Fig. 14 A), carpus

with teeth on inner margin and with 2 stiff acuminate setae on outer

distal corner, dactylus 3 times longer than propodus, with simple

setae. Pereopod 3 (Fig. 14 B), basis longer than half of pereopod,

carpus/propodus: 1.9, tiny dactylus with a long curved terminal seta.

Pereopod 4 (Fig. 14 C), basis shorter than half of pereopod, carpus/

propodus: 2.9, dactylus as in previous pair. Pereopod 5 (Fig. 14 D),

basis shorter than half of pereopod, carpus/propodus: 1.6, same type

of dactylus.

Female —Maxilliped 3 (Fig. 14 E), as in male. Pereopod 1 (Fg. 14 F),

teeth only on outer margin of basis, carpus shorter than propodus.

Pereopod 2 (Fig. 14 G), as in male. Pereopods 3-5 (Fig. 14 H—J),

SCHIZOCUMA AND STYLOPTOCUMA 161

Fig. 11 Styloptocuma dayae (Jones, 1984) immature male A. maxilliped 3; B. pereopod 1; C. pereopod 2; D. pereopod 3; E. pereopod 4; F. pereopod 5.

Scale bar (in mm): A —F 0.3.

very elongated and slender, with the same ratio between articles as Cumella formosa Jones, 1984: 231-233.

in male. Cumella (Styloptocuma) formosa Watling, 1991: 752.

Styloptocuma formosum Bacescu, 1992: 264.

2 OUTSET) OSES EDO ESIEAE) DESCRIPTION. To the description of the adult female in Jones

Figs 14, 15 (1984) the following details are added: Antenna 2 (Fig. 14 B), with

162 I. PETRESCU

Fig. 12 Styloptocuma echinatum (Jones, 1984) immature male A. antenna 1; B. mandible; C. maxilla 1; D. maxilla 2; E. maxilliped 1; F. maxilliped 2; G.

maxilliped 3; H. pereopod 1. Scale bars (in mm): A 0.1; B—E 0.05; F 0.1; G 0.1; H 0.2.

SCHIZOCUMA AND STYLOPTOCUMA 163

Fig. 13 Styloptocuma echinatum (Jones, 1984) A — D. immature male; E-J. female A. pereopod 2; B. pereopod 3; C. pereopod 4; D. pereopod 5; E.

maxilliped 3; F. pereopod 1; G. pereopod 2; H. pereopod 3; I. pereopod 4; J. pereopod 5. Scale bars (in mm): A —D 0.3; E 0.5; F—J 0.5.

164 I. PETRESCU

Fig. 14 Styloptocuma formosum (Jones, 1984) female A. antenna 1; B. antenna 2; C. mandible; D. maxilla 1; E. maxilla 2; F. maxilliped 1; G. maxilliped

2. Scale bars (in mm): A, B 0.1; C-G0.1.

SCHIZOCUMA AND STYLOPTOCUMA 165

Fig. 15 Styloptocuma formosum (Jones, 1984) female A. maxilliped 3; B. pereopod 1; C. pereopod 2; D. pereopod 3; E. pereopod 4; F. pereopod 5. Scale

bars (in mm): A 0.25; B—F 0.3.

166

2 articles and 2 plumose and one simple setae. Mandible (Fig. 14 C

), pars incisiva and lacinia mobilis with 4 teeth . Maxilla | (Fig. 14

D), palp with 2 glabrous filaments. Maxilla 2 (Fig. 14 E), a row of

fine, small setae between outer margin of protopod and endites.

Maxilliped 1 (Fig. 14 F), carpus with hand-like flattened setae with

6 denticles, more fully developed and rounded dactylus. Maxilliped

2 (Fig. 14 G), with robust articles, propodus with plumose setae.

Maxilliped 3 (Fig. 15 A), basis with a very short inner process,

setules on outer margins of basis and carpus. Pereopods 3—5 (Fig. 15

D-F), basis with teeth on inner margin, 3™ pair with longer basis, 5"

one with longer carpus, short dactylus with long curved terminal

seta.

REMARKS. Antenna | (Fig. 14 A) as described in Jones (1984).

Pereopod | (Fig. 15 B) has teeth on outer margin and 2™ pair (Fig. 15

C) has teeth on inner margin (versus glabrous in Jones).

Key for the identification of Styloptocuma species

1 Eye lobe not exceeding pseudorostrum .............:0:csceseesessereesereees 2

- ByevlobeexceedingspsendOnOs tiie recseeee eee ee ener ees 14

2 Pseudorostrum passes beyond the level of the anterior corner.... 3

- Pseudorostrum not or scarcely passing beyond the level of the

ANCESTOR COMMER: 2 sciscwzisves Gacceuceut vacsei Rance ssctbesSeenceredecencre eons 3)

3 Rows of spines on lateral sides of pleom ..............:.::eccsseseeseeeeeee 4

- Without spines on lateral sides of Pl€OM ..........-..:ceceeseeesteeeteeeeeeees

Be 2. tn er TN OE OR ae: screed S. aculeatum (Jones, 1984)

4 Spines on pseudorostrum, pereopods and uropods ...............-202-

1 5 SER ORT on aceaao i echicwrdacceos ee DOA S. echinatum (Jones, 1984)

= No spines on pseudorostrum, pereopods and uropod ...................-

Ask a AO Cn cs ee Site des Ae S. erectum (Jones, 1984)

3) Rows of spines on lateral sides of pleon .............::::csceseeeeeeeees 6

- Without spines on lateral sides of pleOn .............ccecceseeseseeeeeeeeeee 2)

6 Carapace wathidorsallispinesie-ss seas ete tees retere ees ecee I

- Carapace without dorsal spines ................ S. extans (Jones, 1984)

di Eye lobe reaching end of pseudorostrum ...........:..ccesecseeseeeeeeeeeees 8

- Eye lobe not reaching end of pseudorostrum ..............::e:ceseeeeeeeee

aa de eaaun Samah tous Desc cas sade eae tote S. concinnum (Jones, 1984)

8 Eye lobe with an apical spine ............... S. cristatum (Jones, 1984)

- Eye lobe without apical spine .............. S. formosum (Jones, 1984)

s) Carapacenwathid onsalts pine Sereseeaseaeseeeetet sce eeeeeese reese ree eee 10

- Carapacerwithoutspineswees crores eee eee ee 13

10 Carapace with double rows of dorsal spines .............:cccccecseeeeeeeees

Sacer eco Ceca LS IS aR oe S. subductum (Jones, 1984)

- Carapace with a single row Of SPINES ............:cececeeceeseeeneeeneeeneees 11

11 Uropodal peduncle 2 x longer than 6th pleonite ....................... 12

- Uropodal peduncle less than 2 x longer than 6th pleonite ............

Wee havea tat cs cucu siotcn tueut cava Sitters: oouencrsaerxae? S. acuminatum (Jones, 1984)

12 Carapace and uropods with many Spine ...........c:ccccceeseeeseenteeneeeee

= Carapace and uropods with fewer Spine .............s:sscceccescereereeeeeeee

Fide este oie iste eu ct sven scented eectareeestences S. gracillimum (Calman, 1905)

I. PETRESCU

13 Uropodal peduncle 2 x longer than 6th pleomit .............cceseseeeeees

PF ay Re rE a? pe ae iat S. angustatum (Jones, 1984)

Uropodal peduncle less than 2 x longer than 6th pleonite ............

Cece ee ERO EE ECE rere S. inermis (Ledoyer, 1997)

14 Pseudoros tiruirin |] Om Gos. case ioc cscn-sasveesttnaete- cn aczecs -esoe ss eee eens 15

- Pseudorostrum Short ...........:esceeeeeeees S. longisipho (Jones, 1984)

15 Two dorsal rows of spines On Carapace ............seeeseeeeeeteneeeeeeees 16

~ One dorsal row of of spines ON Carapace ...........-:.ssscesceeecesceceeceees

SededusbDauees chs deed oieseaws Pete isan eat S. egregium (Hansen, 1920)

16 Body and uropods densely spinose, pereopods less serrated ........

De a eras een been, Spe ails Aen S. antipai Bacescu & Muradian, 1974

- Body and uropods with fewer, shorter spines, pereopods more

S@irated ce cscccse Mes cece. cc Re ease S. bishopi (Jones, 1984)

PHYLOGENETIC REMARKS

Both Schizocuma and Styloptocuma with mixed characters seem to

be earlier separated from the branch of Cumella group than the other

genera (Almyracuma Jones & Burbanck, 1959, Atlantocuma Bacescu

& Muradian, 1974, Claudicuma Roccatagliata, 1981, Cumella Sars,

1865, Cumellopsis Calman, 1905, Elasocumella Watling, 1991,

Platycuma Calman, 1905) and evolved in specific ways in the deep

sea preserving more characters common with Nannastacus group

(Nannastacus Bate, 1865, Scherocumella Watling, 1991, Schizotrema

Calman, 1911), characters absent to the other deep sea mentioned

genera of the Cumella group. Styloptocuma seems to be closer to

Nannastacus within the group of Cumella than Schizocuma.

ACKNOWLEDGEMENTS. [am grateful to Miranda Lowe from the Depart-

ment of Zoology, The Natural History Museum, London, for the loan of the

studied material; to the late Acad. Mihai Bacescu for the valuable references

and discussions; to the late Norman Jones for suggestions regarding this

study and for suggesting a suitable institution for depositing the materials

studied by him; and to Aurora Dinu who inked the drawings.

REFERENCES

Bacescu, M. 1972. Archaeocuma and Schizocuma, new genera of Cumacea from the

American tropical waters. Revue Roumaine Biologie.Série Zoologie, 17 (4), 241—

250.

— 1992. Cumacea II (Fam. Nannastacidae, Diastylidae, Pseudocumatidae,

Gynodiastylidae et Ceratocumatidae), 8, 175 — 468. In: Gruner, H. E. & Holthuis L.

B. (eds) Crustaceorum Catalogus. SPB Academic Publishing, The Hague.

& Muradian, Z. 1974. Campylaspenis, Styloptocuma, Atlantocuma, new genera

of Cumacea from the deep waters of the Atlantic. Revue Roumaine Biologie. Biologie

Animale, 19 (2), 71-78.

Holthuis, L.B. 1990. Styloptocuma Bacescu & Muradian, 1974 (Crustacea, Cumacea):

proposed conservation with designation of S. antipai Bacescu & Muradian, 1974 as

the type species Bulletin Zoological Nomenclature, 49 (4), 264.

Jones, N.S. 1984. The family Nannastacidae (Crustacea, Cumacea) from the deep

Atlantic Bulletin British Museum (Natural History.) Zoology 46 (3), 207-289.

Ledoyer, M. 1983. Contribution 4 I’ étude de |’ écologie de la faune vagile profonde de

la Méditerranée nord-occidentale 2. Les Cumacés (Crustacea) Tethys, 11 (1), 77.

1997. Les Cumacés (Crustacea) des campagnes Eumeli 2., 3 et 4 au large du Cap

Blanc (est Atlantique tropical) Journal Natural History, 31, 841-886.

Watling, L. 1991. Rediagnosis and revision of some Nannastacidae (Crustacea:

Cumacea) Proceedings Biological Society Washington, 104 (4), 751-757.

Bull. nat. Hist. Mus. Lond. (Zool.) 66(2):167—170

Issued 30 November 2000

A new species of Sigambra (Polychaeta,

Pilargidae) from the abyssal plains of the

NE Atlantic

q - ‘

xy (230048. 1)

GORDON L J PATERSON AND ADRIAN G. GLOVER

Polychaete Research Group, Department of Zoology, The Natural History Museum, London SW7 5BD, UK.

INTRODUCTION

During an intensive study of the benthic communities of the

NE Atlantic abyssal plains (Rice et al. 1994), a new species of

Sigambra was identified. It was conspicuous in being one of the

more abundant species and certainly the dominant predator. The

species was widespread, being recorded from study sites from the

Cap Verde Abyssal Plain in the south to the Porcupine Abyssal Plain

in the north.

MATERIAL AND METHODS

All specimens were collected using a modified United States Naval

Electronics Laboratory. spade box corer (SBC). Samples from the

Porcupine, Madeira and Cape Verde Abyssal Plains were sectioned

horizontally into 0-1 cm, 1-3 cm and 3-5 cm layers and processed

through a number of sieves — 1, 0.5 and 0.3 mm. Samples from the

Tagus Abyssal Plain were taken with a vegematically modified box

corer and only the inner nine subcores were processed through a 0.3

mm sieve.

MATERIAL STUDIED

Specimens have been deposited in a number of taxonomic institu-

tions and corresponding registration numbers are given below.

Abbreviations: AM — The Australian Museum, Sydney; LA — Los

Angeles County Museum of Natural History; MNHN — Museum

National d’ Histoire Naturelle, Paris; BMNH — The Natural History

Museum, London; NMNH — National Museum of Natural History,

Smithsonian Institution; NMS — The National Museums of Scot-

land; NMW - The National Museum of Wales; ZH Zoologisches

Institut und. Museum, Hamburg; ZMUC — Zoological Museum,

Copenhagen.

Holotype: Porcupine Abyssal Plain Challenger II Criuse 111:

53201#29 48°51.5' N 16°29.6' W, 4844 m, sediment layer 1-3 cm

0.5mm sieve, 14/4/1994 (BMNH 2000. 1852).

Paratypes: Porcupine Abyssal Plain the following samples cen-

tred on 48°50' N 16°30' W in 4850 m:

Discovery Cruise 185: 11908#18: 1—3cm 0.3 mm sieve 1| ind. 28/8/

1989.

Challenger IT Cruise 79: 52701#5: 1-3 cm, 0.3mm sieve 4 ind.; 1—

3cm 0.5mm sieve 2 ind (NMSz: 2000.214).16/5/1991.

52701#9: 1-3 cm 0.5mm | ind (ZMH). 17/5/1991.

52701#25: 1-3 cm 0.3mm sieve | ind.(MNHN-POLY 53); 0-1 cm

0.5 mm sieve | ind (NMW.Z: 2000.070).; 3-5 cm 0.5mm sieve 2

ind (NMNH 186794). 20/5/1991;

52701#29: 1-3 cm 0.3 mm sieve | ind. (AM); 1 ind. (ZMUC-POL-

1013 21/5/1991.

52701#47 1-3 cm 0.3 mm sieve | ind. (LA) 21/5/1991.

Challenger Cruise 111: 53201#23 1-3 cm 0.3 mm 1 ind. 13/4/1994;

53201#26 1-3 cm 0.3 mm sieve | ind., 1-3 cm 0.5 mm sieve 2

ind., 3-5 cm 0.3 mm | ind. 14/4/1994;

53201 # 29 1-3 cm 0.25 mm sieve | ind., 1-3 cm 0.5 mm sieve |

ind., 3-5 cm 1 mm sieve ind. 14/4/1994;

53205#2 0.3 mm 0-1 cm sieve | ind., 3—5 cm 0.5 mm sieve | ind.,

18/4/94.

Tagus Abyssal Plain centred on 38°N 11°W 5035 m: Discovery

Cruise 186: SBC365 3 ind. 26/9/1989; SBC366 1 ind. 26/9/1989;

SBC367 5 ind. 26/9/1989; SBC368 5 ind., SBC369 2 ind. 27/9/

1989; SBC371 2 ind. 28/9/1989.

Madeira Abyssal Plain centred on 31°10' N 21°10' W 4985m:

Discovery Cruise 194: 12174#35: 1-3 cm 0.3 mm sieve 2 ind.: 1-3

cm (0.5 mm sieve | ind.; 3—5 cm 0.5 mm sieve 3 ind. 21/8/1990.

12174#43: 1-3 cm 0.3 mm | ind. 22/8/1990.

12174#53: 1-3 cm 0.3 mm sieve 2 ind. 23/8/1990

12174 #60: 1-3 cm 0.3 mm sieve | ind. 24/8/1990.

12174#80 0-1 cm 0.3 mm sieve | ind.; 5—10 cm 0.5 mm sieve | ind.

28/8/90.

Cape Verde Abyssal Plain centred on 20°N 30°W 4500-4600 m: Dis-

covery Cruise 204: 12600#32 0-1 cm 0.3 mm sieve | ind. 6/10/1994.

In addition the following material was examined: Sigambra bidentata

Britaev & Saphronova, 1981 Natural History Museum Polychaete

Collection Z1986:178-183 (5 paratypes), Vityaz Stn 7488 38°

41°N:133° 45’E 1550 m Sea of Japan. Sigambra gracilis Britaev &

Saphronova, 1981 ZR1986.184—185 (2 paratypes), Vostok Bay, Sea

of Japan. Sigambra phuketensis Licher and Westheide, 1997 Z1993.

15—16 (2 Paratypes), Bang Tao, W. Phuket Island, Thailand.

TAXONOMIC ACCOUNT

Family PILARGIDAE

Genus SIGAMBRA O.F.Miiller, 1858

Species S. magnuncus sp. nov.

(Figs 1-5)

DESCRIPTION

Holotype: Length 3.7 mm for 33 chaetigers, greatest width of

body 0.3 mm.

Paratypes: Range from length 0.5 mm for 13 chaetigers to 10.5

mm for 50 chaetigers, number of segments depends on size of

individual. (Fig. 5).

Body unpigmented; slightly flattened anteriorly, but becoming

more rounded posteriorly; anterior chaetigers widest.

168

939134 15K¥

om:

59128 i5Ky¥ &5

Fig.1 SEMs of Sigambra magnuncus (MAP Discovery Investigations

12174#60 0.5 mm sieve, 1—3 cm) A. General view of individual. B. View

of notopodia, note the small capillary chaeta in each notopodium

Prostomium rounded, slightly indented laterally at insertion of

palps and prostomium. Palps biarticulate with relatively long

palpostyles; palpophores fused distally over half their length. Three

antennae, median antenna longest, situated slightly posterior to

G.L.J. PATERSON AND A.G. GLOVER

959133 15K¥ 250 “120um

Fig. 2 SEMs of Sigambra magnuncus (MAP Discovery Investigations

12174#80 0.5mm sieve, 1-3 cm) Dorsal view of anterior region.

laterals in smaller specimens, but more level with them in larger

individuals. A pair of cushion like nuchal organs, situated on either

side of the median antennae. Eyes absent. Pharynx without jaws,

armed with eight equal size, slightly pointed papillae.

Peristomium approximately twice as long as first chaetiger. Two

pairs of long tapering tentacular cirri, dorsal cirri longer than ventral,

and slightly shorter than median antennae. A row of low cushion-

like papillae (sense organs) extending across dorsal surface of

peristomium (may only be visible under high magnification).

Fig. 3 a Parapodium from mid region, anterior view. b notopodial

hook, ¢ & d neurocapillaries. Scale bars = 0.1 mm.

A NEW N.E. ATLANTIC POLYCHAETE

P +

(3)

3 L

) L

ro} + PAP/53201 L

3 © PAP

am TAP i

m €£0S li

| ° MAP

T T T T T =" > 1 ay T T T 1 To

(0) 2 4 6 8 10 12

Total Length (mm)

Fig. 4 Graph showing the relationship between size and number of

chaetigers. Individuals from different sample sites are identified. PAP—

Porcupine Abyssal Plain, MAP — Madeira Abyssal Plain, TAP — Tagus

Abyssal Plain, EOS — Cap Verde Abyssal Plain.

Parapodia biramous; anterior parapodia laterally orientated, be-

coming more dorsal in median and posterior chaetigers. A row of

cushion-like papillae extending across dorsal surface between

notopodia on each chaetiger.

Notopodia pointed, with straight, blunt-tipped internal aciculae.

Dorsal cirri of chaetiger 1 long, thin and tapering; nearly equal in

length to median antenna; subsequent dorsal cirri initially shorter

with wider bases, but in posterior chaetigers becoming more slender

longer and projecting dorsally. Large hooks emergent on chaetiger 3

(Fig. 1b, 2, 3b) until one or two chaetigers from pygidium; in

posterior chaetigers hooks meeting in midline. Short, delicate capil-

laries projecting from most notopodia, just one in anterior chaetigers

(Fig. 1b, 3a), usually becoming two in posterior segments.

Neuropodial lobes pointed, with blunt-tipped, straight aciculae

(Fig 3a); initially orientated laterally but become more vertical and

dorsal in posterior chaetigers. Ventral cirri absent on chaetiger 2; on

Se ER ES ee es ee ieee eee oe

2 L

3S L

ne)

£&

ro)

fe} Ke

ot Ime eal

0 2 4 6 8 10 12

Total Length (mm)

Fig.5 Histogram showing the range of sizes of S.magnuncus collected in

the NE Atlantic.

169

other chaetigers thin and tapering, equal to or shorter than neuro-

podia, equal to or slightly longer than dorsal cirri. Neurochaetae

simple capillaries, slightly expanded at the base just free of the

podia, tips quickly taper into a prolonged point (Fig. 3 c,d).

Pygidium with two tapering cirri. Anus dorsal.

DISTRIBUTION. S. magnuncus has been recorded from the abyssal

plains of the NE Atlantic at depths from 4000 m to 5085 m.

ETYMOLOGY. The name of this species derives from the large

conspicuous hooks on the notopodia (Latin magnus — large uncus —

hook).

DISCUSSION

Taxonomic Affinities

Licher & Westheide (1994) suggested that the Pilargidae was not a

separate family and that species in the family belonged in the

Hesionidae. This hypothesis has been rejected by Pleijel (1998) and

Pleijel and Dahlgren (1998) on the basis that Licher & Westheide’s

(1994) original study was not rooted in an appropriate outgroup.

Subsequent analysis by Pleijel and Dahlgren (1998) indicated that

the Pilargidae and Hesionidae were different and non-overlapping

groups. We, therefore, retain the family Pilargidae.

Including S. magnuncus, there are 17 described species of

Sigambra (Licher and Westheide, 1997). Based on examination of

Sigambra material in the NHM and the revision of Licher &

Westheide (1997), S$. magnuncus shares certain features with S.

ocellata (Hartmann-Schréder, 1959), S. bidentata Britaev &

Saphronova, 1981 and S. gingdaoensis Licher & Westheide, 1997,

namely the ventral cirrus is missing on chaetiger 2 and there are

eight papillae in the pharynx (Licher & Westheide, 1997). The

relative proportions of the dorsal and ventral cirri suggest similari-

ties with S. ocellata, however, in S. magnuncus the notopodial hooks

start on chaetiger 3 rather than chaetiger 6 as in S. ocellata. In

S. bidentata and S. gingdaoensis the notopodial hooks can start from

chaetigers 3, similar to S$. magnuncus, but in addition to differences

in cirral length, S. magnuncus differs from S. bidentata in not having

bidentate neurochaetae. S. magnuncus differs from S. gingdaoensis

in having one capillary notochaeta in anterior chaetigers, becoming

two in posterior chaetigers, whereas in S. gingdaoensis there are

always two notopodial capillaries. Finally, the notopodial hooks in

S. magnuncus are much larger than in comparable sized individuals

of the other species.

Growth and abundance

S. magnuncus Was most common in samples from the Porcupine and

Tagus abyssal plains with densities of 4 to 32 individuals per m?,

while lower numbers were found in the Madeira and Cap Verde

samples. This was partly due to lower overall densities of polychaetes

at these latter sites (Paterson et al. 1998), but their distribution

suggests that this species is more common in northern abyssal areas.

Also analysis of the distribution within the sediment suggests that

this species is found within the sediment rather than on the surface.

There is a good range of sizes within the collection, allowing

allometric changes to be noted. Notopodial hooks in smaller speci-

mens appear to be extremely large, but in larger specimens these

hooks are proportionately smaller. This suggests that hooks are

produced at a set size, not affected by growth. The hooks always

occur first on chaetiger 3.

Size of specimens ranges from 0.5 to 10.5 mm, although most

170

individuals were between 0.75 to 4.5 mm long (Fig. 5). The relation-

ship between length of specimen and number of chaetigers is given

in Fig. 4. The graph indicates that initially as individuals increase in

length so the numbers of chaetigers increases linearly, however, at

the upper size there is wide variation in numbers of chaetigers,

suggesting that there may be an upper limit to chaetiger number.

Growth in Sigambra grubii Muller, 1858 also appears to show a

linear relationship between length and number of chaetigers over a

similar size range as S. magnuncus (Salazar-Vallejo, 1990). How-

ever, there was more variation in the relationship between size and

the chaetiger on which the first hook appeared.

ACKNOWLEDGEMENTS. We would like to thank Dr Andrew Mackie (Nat-

ional Museum of Wales) and Alex Muir (NHM) for reviewing the manuscript.

The assistance of the Electron Microscope and Mineral Analysis Division in

the preparation of specimens for the SEM is gratefully acknowledged. The

specimens were collected during a number of oceanographic expeditions and

the authors would like to thank the officers, crew and scientific parties of

Discovery 185, 186, 194, 206 and Challenger 79, 111.We would also like to

thank Dr John Gage, Peter Lamont (Scottish Association for Marine Science),

Dr Brian Bett (Southampton Oceanographic Centre) and Joel Galleron

(CENTOB) for making material available to us. This work was partly

supported by acontract from EU Marine Science and Technology programme

Contract No MAS2-CT920033, which is gratefully acknowledged.

G.L.J. PATERSON AND A.G. GLOVER

REFERENCES

Britaev, T.A. & Saphronova, M.A. 1981. New species of the family Pilargidae

(Polychaeta) from the Sea of Japan and revision of the genus Cabira. Zoologichesky

Zhurnal 60: 1314-1324.

Hartmann-Schroder, G. 1959. Zur Okologie der Polychaeten des Mangrove-Estero-

Gebietes von El Salvador. Beitrdge zur Neotropischen Fauna 1: 69-183.

Licher, F. & Westheide, W. 1994. The Phylogenetic position of the Pilargidae with a

cladistic analysis of the taxon — facts and ideas. In Dauvin, J.C., Laubier L. & Reish

D. J. (Eds) Actes de la 4¢me Conférence internationale dea Polychétes. Mémoires de

la Muséum national d’ Histoire Naturelle 162: 223-235.

Licher, F. & Westheide, W. 1997. Review of the genus Sigambra (Polychaeta:

Hesionidae), redescription of S. bassi (Hartman, 1947), and descriptions of two new

species from Thailand and China. Steenstrupia 23: 1-20.

Paterson, G.L.J., Wilson, G.D., Lamont, P. and Cosson, N. 1998. Hessler and Jumars

revisited. Polychaete assemblages from the abyssal plains of the North Atlantic and

Pacific Oceans. Deep-sea Research I. 48: 225-252.

Pleijel, F. 1998. Phylogeny and classification of Hesionidae (Polychaeta). Zoologica

Scripta 27: 89-163.

Pleijel, F. and Dahlgen, 1998. Position and delineation of Chrysopetalidae and

Hesionidae (Annelida, Polychaeta, Phyllodocida). Cladistics 14: 129-150.

Rice, A.L. , Thurston, M.H. and Bett, B.J. 1994. The IOSDL DEEPSEAS pro-

gramme: introduction and photographic evidence for the presence and absence of a

seasonal input of phytodetritus at contrasting abyssal sites in the northeastern

Atlantic. Deep-Sea Research I 41: 1305-1320.

Salazar-Vallejo, S.I. 1990. Redescription of Sigambra grubii Muller, 1858 and

Hermundura tricuspis Muller, 1858 from Brazil and designation of neotypes

(Polychaeta: Pilargidae). Journal of Natural History 24 507-517.

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Basal resolution of laophontid phylogeny and the paraphyly of

Esola Edwards. R. Huys and W. Lee. 2000. Pp. 1-107. £40.30

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