International Society for the Study

and Conservation of Amphibians

(International Society of Batrachology)

SEAT

Laboratoire des Reptiles et Amphibiens, Muséum national d'Histoire naturelle,

25 rue Cuvier, 75005 Paris, France

BOARD FOR 1993

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Source : MNHN, Paris

AINTES

INTERNATIONAL JOURNAL OF BATRACHOLOGY

December 1993 Volume 11, N° 4

Alytes, 1993, 11 (4): 117-139. 117

The tadpoles of the brown frogs

Rana [graeca] graeca and

Rana [ secs] Hülien (Amphibia, Anura)

Britta GRILLITSCH*, Heinz GRILLITSCH**,

Alain Dusois*** & Heinz SPLECHTNA****

* Institute of Laboratory Animal Science, University of Veterinary Medicine,

Linke Bahngasse 11, 1030 Vienna, Austria

** Naturhistorisches Museum Wien, Burgring 7, 1014 Vienna, Austria

*** Laboratoire des Reptiles et Amphibiens, Muséum national d'Histoire naturelle,

25 rue Cuvier, 75005 Paris, France

*##* Institute of Zoology, University of Vienna, AlthanstraBe 14, 1090 Vienna, Austria

External morphology and buccopharyngeal characters of the tadpoles of

Rana [graeca] graeca and Rana [graeca] italica are described in detail. Both

characterize the larvae as well adapted to flowing waters. The most distinctive

oral and buccal features are the increased number of tooth rows, the high

number of papillae in both buccal floor and buccal roof arena, and the large

prelingual palps with elongate lobes.

Larvae from Italy resemble those from Greece. However, samples from

both countries differ slightly but significantly in a variety of features. This

supports the existence of two taxons, subspecies or species, graeca for the

populations of the Balkans and italica for those of the Apennines. 4] iothèque Centrale Muséum

QUIL

INTRODUCTION 3 3001 00111588 8

Rana graeca Boulenger, 1891 (Greek frog, stream frog) is the only European anuran

which was first recognized by its larva. The story of the tadpoles’ discovery by the French

batrachologist Louis-François HÉRON-ROYER is reported by BOULENGER (1891a) and

confirmed by a letter from HÉRON-ROYER to Raymond ROLLINAT, dated 27 September

1891 (library, Laboratoire des Reptiles et Amphibiens, Muséum national d'Histoire

naturelle, Paris), where he writes: “Je viens de recevoir une lettre de Boulenger qui

BIBL. DU

je Source : MNHN, Paris

118 ALYTES 11 (4)

m'annonce une nouvelle grenouille pour la faune Européenne, sur un têtard de Grèce que

je lui ai déterminé n'étant ni R. fusca ni R. Latastei. I] vient d’en faire une Rana graëca.”

Geographical disjunction (map in ARNOLD & BURTON, 1978) and morphometric

divergences between adult specimens from the Balkans and from the Apennines gave rise

to discussions on intraspecific variation (ARNOLD & BURTON, 1978) and taxonomic status

(LANZA, 1983). The establishment by Dugois (1987)! of two subspecies, R. graeca graeca

(Balkans) and R. graeca italica (Apennines), was based on external morphometric

differences in adults, whereas the suggested raising of italica to specific rank (PICARIELLO

et al., 1990; CaPuLA, 1991) resulted from allozyme studies.

Literature on larval morphology of R. graeca is scarce. Oral disks are depicted in

BOULENGER (1891b) and GÜNTHER (1985), well developed larvae in BOULENGER (1891b)

and BEsKOV (1970). The former additionally provided a short description and differential

diagnosis and the latter contributed to the knowledge of the tadpole’s biology. Both

authors refer to a small number of Balkan specimens only. No further morphological

investigations are available and there are no comparative data on tadpoles from Italy.

The primary goal of the present paper is to describe the external and buccopharyngeal

characters of graeca and italica larvae in the process of development. This is done for a

variety of features (also for those where no significant differences between tadpoles from

the Balkans and the Apennines were found), to make data available for comparison with

other South European brown frog species.

MATERIAL AND METHODS

Specimens from five Greek and seven Italian localities were investigated (Table 1).

Number of specimens is 212 for detailed morphometric analysis, 364 for size-stage diagram

(fig. 4), and 282 for tooth rows counts. Description of buccopharyngeal structures refers

to five tadpoles each (stages 36-38) from both Italy and Greece (asterisks in Table 1) and

is based on stereomicroscopy (n = 6) and scanning electron microscopy (n = 4).

External morphology is described using established parameters introduced by

BOULENGER (1897-1898), and defined in more detail by GRILLITSCH (1984) and GRILLITSCH

et al. (1989). The measurements do not represent true distances but projections to the

tadpole’s frontal and sagittal planes respectively (Table 11). Distances between pupillae or

nostrils mean distances between the centres of these organs. Tooth rows of both upper and

lower lip are numbered from the margin towards the centre of the oral disk, as is done in

the classic terminology of BOULENGER (1891b). The length of a tooth row is defined as the

straight distance between its ends in the expanded oral disk. For tooth rows formula

(number of upper rows / number of lower rows), rows are counted as one whether

continuous or interrupted, uni- or bilateral.

1. Several authors (PICARIELLO et al., 1990; CapuLA, 1991; DUELLMAN, 1993) credit the name italica to

“Dunois (1985), although the paper where this name first appeared was published on 26 January 1987

(Dunois, 1988a), and should therefore be quoted as “DuBois (1987)".

Source : MNHN, Paris

Table I. — Material investigated. MNHN: Muséum national d'Histoire naturelle, Paris; NMW: Naturhistorisches Museum

Wien; *: samples used for buccopharyngeal analysis; habitat: B, brook; T, torrent; R, river; P, pond; morphometry:

specimens used for detailed morphometric analysis (Table III); size-stage graph: specimens used in size-stage graph (fig. 4);

tooth rows counts: specimens used in tooth rows counts;

specimens.

: number of specimens; RS: range of Gosner’s (1960) stages of

WAISAN

ra 8

Morphometry | Size-stage graph | Tooth rows counts

Specimens series Country and region Locality Habitat | Date

n (RS) n (RS) n (RS)

MNHN 1985.1777-1815 | Greece, Peloponnissos, Ahaia | Kato Vlassia (760-770 m) T 13.08.82 | 34(28-39) | 36 (28-40) 34 (28-40)

NMW 29181:1-20 Greece, Peloponnissos, Ahaia | Krathis potamos near Zivlos (550m) | B | 06-10.08.84 | 12(31-39) | 15 (31-43) 14 6141)

MNHN 1985.1817-2024 * | Greece, Peloponnissos, Arkadia | Kalomeri (980 m) T 14.08.82 66 (29-39) 182 (29-45) 117 (29-41)

NMW 27637:1-20 Greece, Peloponnissos, Ilia Oros Minthi near Nea Figalia (750 m) B 16.08.83 15 (27-39) 26 (27-41) 24 (27-41)

NMW 29180:1-20 Greece, Peloponnissos, Korinthia | Olvios potamos near Feneos (800 m) B 06-10.08.84 10 (28-39) 10 (28-41) 10 (28-41)

MNHN 1985.1756-1775 Italy, Abruzzo, Teramo Fiume Salinello (1040 m) T 08.08.85 3 (34-39) 20 (34-44) 12 (34-41)

MNHN 1985.1719 Italy, Basilicata, Potenza Fontana d'Eboli (1010 m) 8 02.08.82 1 G0) 1 G0) 1 60)

MNHN 1985.1720 Italy, Basilicata, Potenza Pecorone (800 m) 4 02.08.82 1637) 137) 137)

MNHN 1985.1504-1560 + | Italy, Calabria, Cosenza Cosentino (1140 m) T |222307.82 | 570839) | 57(28-30) 55 28-39)

MNHN 1985.1564-1674 |ltaly, Calabria, Cosenza Fiume Savuto (1070 m) R+P| 2407.82 167) 16n

MNHN 1985.1678-1691 Italy, Lazio, Frosinone Vallegrande (530-570 m) À 01.08.82 12 (37-39) 14 (37-40) 14 (37-40)

MNHN 1985.1776 laly, Marche, Ascoli Piceno |Trisungo (630 m) B 09.08.85 - 142)

VNLHOH1IdS @ SIO4NC ‘HOSLITINO ‘HOSLITIIT)

6II

Source : MNHN, Paris

120

ALYTES 11 (4)

Table II. — Definition of distances measured, including explanation of abbreviations

used. P: projection to frontal (F) or sagittal (S) plane.

Abbreviation

Definition

Maximum height of tail (including upper and lower tail fin)

Number of inframarginal oral papillae

Maximum height of lower (ventral) tail fin

Length of first (outermost) tooth row of lower lip

Length of second tooth row of lower lip

Number of marginal oral papillae

Internarial distance

Naro-pupillar distance

Maximum width of oral disk

Interpupillar distance

Rostro-narial distance

Distance: tip of snout - opening of spiracle

Distance: tip of snout - insertion of dorsal tail fin

Distance: tip of snout - vent (snout-vent length)

Distance: tip of snout - tip of tail (total length)

Maximum height of upper (dorsal) tail fin

Length of first (outermost) tooth row of upper lip

Length of median gap between portions of second tooth row of upper lip

Length of one portion of second tooth row of upper lip

Distance: vent - opening of spiracle

Distance: vent - tip of tail (length of tail)

Nomenclature of buccopharyngeal structures is largely in accordance with WASSERSUG

(1976, 1980); definition of developmental stages follows GOsNER (1960).

Tadpoles examined comprise developmental stages 27 through 45; detailed morpho-

metric analysis was restricted to stages 28-39. Since body proportions change during

growth, morphometric data have to be accompanied by the size or developmental stage

they refer to. In the present paper the assignment to size classes was preferred because of

Statistical reasons. Since there is a fair positive linear correlation between size and

developmental stages 27 through 39 (fig. 4), they are easily convertible.

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 121

Measurements were done optically with a digital display length-measuring unit (Wild

MMS 235). Preparation for SEM examination (Jeol JSM-35 CF) comprised dehydration

(ethanol), critical-point-drying (acetone, liquid carbondioxide), and gold sputter surface-

coating.

Statistical analyses were processed using SPSS-X and SAS. Significances (4) were

calculated by means of Student t test and Mann-Whitney U test. Selection rule for

discriminant analysis (fig. 10) with stepwise variable selection was: maximize minimum

Mahalanobis distance. For both the pooled Greek and the pooled Italian samples,

homogeneity was proved by Kruskal-Wallis ANOVA for each measurement within each

of the six size classes, where sufficient material was available. For references concerning

Haldane’s coefficient of variation (Table III), see DELAUGERRE & DuBois (1985).

RESULTS

GENERAL APPEARANCE, COLOUR AND PATTERN (PRESERVED SPECIMENS) (FIGS. 1-3)

In Greek and Italian tadpoles, the slightly depressed ovoid body continuously extends

into the robust, fairly elongate tail which lacks a marked constriction at its base. Both

dorsal and ventral caudal fins are low and slightly convex with almost parallel edges. The

height of the trunk is not or not clearly exceeded by that of the tail fin which is more or

less tapering but never acutely pointed and sometimes even obtuse. As is typical of

tadpoles of the subgenus Rana, the spiracular tube is sinistral and directed backwards and

slightly upwards. It opens about halfway between tip of snout and vent, more frequently

a little closer to the anterior than to the posterior end of the trunk, especially in advanced

developmental stages. The vent opens subdextral, close to the edge of the ventral fin. The

eyes are moderately sized, close to one another, not visible from below.

The trunk is dark greyish-brown above due to a close speckling with black. The

ventral parts and the muscular portion of the tail are much lighter, the latter speckled with

black. Caudal fins are greyish, transparent, with small dark spots or arborescent markings,

mainly in the dorsal portion. There are neither distinct changes in colour or pattern during

larval development, nor are there differences between Greek and Italian specimens.

SIZE AND PROPORTIONS OF TRUNK AND TAIL (TABLE III)

The tadpoles on which this study is based were all collected in the months of July and

August (Table I), i.e. several months after the breeding period, which occurs in February

to April in Italy (BAGNOLI, 1985; PICARIELLO et al., 1993) as well as in the Balkans

(BEskOv, 1970; NôLLERT & NÔLLERT, 1992). Total lengths (TL) of the smallest tadpoles

examined were 20.2 mm (Italy, stage 28) and 21.5 mm (Greece, stage 28). So we cannot

contribute to the size of hatchlings which is 9.1-9.5 mm for Bulgarian specimens (BESKOV,

1970). Maximum TL were 48.5 mm (Italy, stage 41) and 58.2 mm (Greece, stage 41),

exceeding the maxima compiled from literature (45 mm, GÜNTHER, 1985; 46.3 mm,

Source : MNHN, Paris

122 ALYTES 11 (4)

Figs. 1-3. — Stage 38 graeca tadpole from Krathis potamos, Greece (NMW 29181): (1) lateral view;

(2) dorsal view; (3) ventral view.

BEskOV, 1970; 48 mm, BOULENGER, 1891a-b; 50 mm, BAGNOLI, 1985). As in adults, the

average TL of Greek larvae clearly surpasses that of Italian ones (fig. 4), what is significant

(x <0.05) in stages 29, 31, 35, 36, 39, 40, 41.

Mean values of VT/SV varied with TL increasing from 0.78 to 1.53 in Italian, and

from 0.92 to 1.45 in Greek larvae, exceeding 0.6 calculated from BOULENGER’s (1891a)

table. In size classes TL 30.0-49.99 mm, Italian tadpoles have longer tails than Greek ones

(« <0.05).

The dorsal tail fin barely reaches the trunk. In Italian tadpoles, the dorsal fin generally

extends a little more towards the trunk, whereas in Greek specimens it is restricted to the

tail region. This difference in ratio SV/SU is significant (4 <0.01) in size classes TL

35.0-44.99 mm.

Older (longer) larvae have relatively lower tail fins. The means of VT/HT vary from

1.46 (young larvae) to 2.88 (advanced stages) in Italian tadpoles, and from 2.26 to 3.81 in

Greek specimens, respectively, indicating conspicuously higher fins in Italian larvae. These

differences are significant (4 <0.05) in specimens longer than TL 25.0 mm.

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 123

DO ——————

L 45

0 46 49

m | 14

16 0 ©

so E a 2

us 4 ù 14

e ire l

PEU 6 4 5 655

EI 3 ? 6110 Fe

41 ; !

2 …13

+ Sipnprs D 1

a 1315 7 à

20 7

4 8 Li

1 LI

10 1 F '

25 30 35 40 45 50

STAGE

-m-italica _g_ graeca

Fig. 4. — Size-stage graph, showing correlation of size (TL) and developmental stage in italica and

graeca tadpoles, including mean value, range, standard deviation and sample size.

On the average, in Italian individuals the heights of dorsal and ventral tail fins are

almost the same (UF/LF around 1.0). In Greek tadpoles, the dorsal fin is usually higher

than the ventral one (means of UF/LF 1.11-1.34). Differences are significant (x <0.01) in

animals longer than TL 30 mm.

Ratios HT/UF and SS/VS reveal no significant differences between Italian and Greek

tadpoles.

POSITION OF EYES AND NARES, WIDTH OF ORAL DISK

The nares are positioned closer to the tip of the snout than to the eyes. Mean values

of RN/NP are a little higher in Greek than in Italian larvae, meaning the nares of the

Italian being closer to the tip of the snout (x <0.1 in size classes TL 30.0-34.99 mm and

TL 40.0-49.99 mm). Ratio PP/NN is not significantly different between Italian and Greek

larvae.

Source : MNHN, Paris

124 ALYTES 11 (4)

nr a

Le y, Un,

NOT

5 ut ï

ds UN

ne mm ur

a”

ag AL

NN MS

til Nr 7e

TI M

«il 4

Fig, 5. — Oral disk of a graeca tadpole (stage 38) from Krathis potamos, Greece (NMW 29181),

stage 38.

BOULENGER (1891a-b) mentions that R. graeca tadpoles differ from their European

“congeners in having the mouth quite as wide as the interorbital space”. Mean values of

PP/OD vary from 1.05 to 1.18. Greek tadpoles show a comparatively wider oral disk (&

<0.05) in size classes TL > 40 mm.

ORAL DISK (FIGS. 1, 3, 5, 6)

The oral disk is in ventral subterminal position. It is expanded laterally and of ovoid

or rectangular shape. Marginal peribuccal papillae (MP) are restricted to the lateral

corners and the posterior margin of the oral disk, and are basically arranged in a single

row at a density of 9-10 per millimetre on the posterior margin. In the lateral corners,

besides solitary inframarginal papillae (IMP), two papillate ridges are descending towards

the beak on each side (figs. 5, 6).

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA

125

Table III. — Descriptive statistics of selected parameters describing graeca (G) and italica

(1) larvae. Size classes are according to the value of TL (mm). n: number of specimens;

min: minimum value; med: median value; X: mean value; max: maximum value; Sx:

standard error of the mean; Sd: standard deviation; V4: HALDANE'S coefficient of

variation. For further abbreviations see Table II.

25.029.909 | 300-1400 | 3503090 | 4004409 | 450.400 | 50 | 55°

549 | 559

Samples 1fclrilclrilclilclilclilc|clc

Stage

" 6 | 2 | 19 | 12 | 15 | 16 | 14 | 34 | 12 | 23 | 8 | 38 | nn | 2

min 28 | 28 | 28 | 27 | 30 | 27 | 33 | 27 | 37 | 51 | 37 | 35 | 38 | 37

med 29 | 30 | 30 |2050| 34 |3536/3637| 36 | 37 | 37 | 38 | 39 | 39 | 38

max 31 | 32 | 35 | 33 | 37 | 37 | 30 | 39 | 39 | 30 | 39 | 30 | 39 | 39

n 6 | 2 | 19 | 12 | 15 | 16 | 14 | 34 | 12 | 23 | 8 | 38 | n1 | 2

min 20.20 | 21.50 | 25.10 | 26.10 | 30.30 | 30.00 | 35.10 | 35.00 | 40.80 | 40.20 | 45.20 | 45.10 | 0.20 | 55.40

x 22.43 | 22.10 | 27.34 | 28.58 | 32.56 | 32.31 | 37.25 | 37.25 | 42.91 | 42.81 | 46.78 | 48.07 | 51.56 | 55.60

max 24.20 | 22.70 | 29.80 | 29.60 | 34.50 | 34.50 | 39.10 | 39.80 | 44.50 | 44.90 | 47.90 | 49.90 | 54.60 | 55.80

sx 073 0.34 | 0.28 | 0.31 | 038 | 0.39 | 026 | 0.39 | 0.32 | 0.36 | 0.22 | 0.42

sd 178 1.49 | 096 | 1.21 | 1.50 | 1.45 | 1.50 | 1.33 | 1.53 | 1.01 | 1.36 | 1.39

A 83 55 | 35 | 38 | 47 | 40 | 41 | 32 | 36 | 22 | 29 | 28

n 6 | 2 [uw | a lis | 16 | 14 | 34 | 12 | 23 | 8 | 38 | n | 2

min 11.40 | 10.70 | 11.40 | 12.00 | 13.70 | 13.40 | 14.70 | 15.30 | 16.60 | 17.40 | 17.00 | 18.30 | 20.20 | 22.40

x 12.73 | 11.60 | 13.34 | 14.23 | 15.00 | 15.76 | 16.22 | 16.92 | 18.10 | 19.24 | 18.49 | 20.20 | 21.26 | 22.75

max 14.80 | 12.50 | 15.20 | 19.40 | 16.00 | 18.90 | 17.80 | 19.60 | 19.30 | 20.60 | 19.40 | 22.40 | 23.30 | 23.10

sx 0.56 024 | 0.51 | 017 | 033 | 024 | 0.18 | 0.25 | 020 | 034 | 0.19 | 0.27

Sd 138 104 | 1.78 | 0.67 | 1.30 | 0.00 | 1.06 | 0.87 | 0.95 | 0.95 | 1.17 | 001

A 113 79 [12845 | 84 | 57 | 63 | 49 | 50 | 53 | 5.8 | 44

VTISV

n 6 | 2 [uw | au lis [16 | 14 | 34 | 12 | 23 | 8 | 38 | n | 2

min 0.51 | 0.82 | 0.69 | 0.48 | 0.97 | 0.41 | 1.16 | 088 | 1.15 | 1.09 | 1.43 | 1.09 | 1.22 | 1.40

x 0.78 | 0.92 | 1.06 | 1.03 | 117 | 1.00 | 1.30 | 1.21 | 1.38 | 1.23 | 1.53 | 1.39 | 1.43 | 1.45

max 110 | 101 | 142 | 136 | 141 | 138 | 1.51 | 1.44 | 1.68 | 1.43 | 1.71 | 1.64 | 1.58 | 1.49

Sx 0.09 0.05 | 006 | 0.03 | 0.07 | 0.03 | 0.02 | 0.04 | 0.02 | 0.04 | 0.02 | 0.03

sd 021 020 | o21 | ou |o27 | 012 | 011 | 014 | ou | ou | o15 | 010

Va 25.40 18.20 | 19.80 | 9.60 | 26.40 | 9.40 | 0.20 | 10.40| 9.00 | 6.70 | 10:90! 6.40

SV/SU

n 6 | 2 [is [ul 14 | 16 | 14 | 34 | 12 | 23 | 8 | 33 | 10 | 2

min 1.13 | 0.99 | 105 | 1.01 | 0.85 | 0.90 | 0.98 | 0.97 | 1.08 | 1.05 | 1.06 | 0.91 | 1.04 | 1.06

x 125 | 1.06 | 1.24 | 118 | 123 | 118 | 121 | 112 | 126 | 116 | 116 | 116 | 112 | 121

max 150/ 113151 134 | 138 | 154 | 144 | 128 | 145 | 128 | 1.35 | 1.45 | 1.24 | 1.35

sx 0.05 0.03 | 0.04 | 0.04 | 0.03 | 0.03 | 0.01 | 0.03 | 0.01 | 0.04 | 0.02 | 0.02

sd 013 0.14 | 0.12 | 0.14 | 014 | 013 | 0.07 | o.11 | 0.07 | 010 | 0.10 | 0.06

Va 10.00 10.60 | 9.50 | 1080 | 1120/1010! 630 | 8.10 | 5.20 | 8.00 | 7.80 | 4.60

Source : MNHN, Paris

126 ALYTES 11 (4)

SSIVS

n 6 2 [18 | un | 14 [16 | 14 | 34 | 12 | 23 | 8 | 33 | 10 | 2

min 0.79 | 0.99 | 0.80 | 0.80 | 0.77 | 0.79 | 0.79 | 0.72 | 0.75 | 0.73 | 0.75 | 0.70 | 0.63 | 0.76

x 0.96 | 1.00 | 0.93 | 0.95 | 0.92 | 0.90 | 0.91 | 0.90 | 0.92 | 0.86 | 0.91 | 091 | 0.89 | 0.82

max 105 | 1.01 | 1.28 | 1.34 | 1.05 | 1.00 | 1.12 | 1.24 | 1.01 | 1.05 | 1.08 | 1.17 | 1.04 | 088

sx 0.05 0.03 | 0.04 | 0.02 | 0.02 | 0.03 | 0.02 | 0.02 | 0.02 | 0.04 | 0.02 | 0.04

sd o.11 0.10 | 0.14 | 0.08 | 0.06 | 0.10 | 0.11 | 0.08 | 0.09 | 0.12 | 0.09 | 0.12

Vu 10.90 10.90 | 14.00 | 8.90 | 6.80 | 11.20 | 12.30 | 8.90 | 10.60 | 13.60 | 10.00 | 12.70

VTHT

n 6 2 [is [un 14 lie | 14 | 34 | 12 | 23 | 8 | 33 | 10 | 2

min 0.97 | 1.78 | 1.30 | 1.28 | 1.66 | 1.00 | 2.10 | 1.88 | 2.27 | 2.88 | 2.25 | 2.90 | 3.51 | 2.97

ES 1.46 | 226 | 209 | 2.44 | 2.24 | 2.47 | 2.52 | 3.22 | 255 | 3.35 | 288 | 3.54 | 381 | 331

max 189 | 2.73 | 283 | 3.31 | 2.78 | 3.58 | 3.39 | 3.01 | 2.90 | 3.92 | 3.19 | 423 | 426 | 3.64

sx 015 o11 | 015 | 0.07 | 017 | 0.10 | 0.08 | 0.07 | 0.07 | 0.11 | 0.06 | 0.08

sd 0.36 0.47 | 0.49 | 0.25 | 0.69 | 0.36 | 0.48 | 0.23 | 0.34 | 0.30 | 0.34 | 026

A 23.50 21.80 | 19.40 | 10.10 | 27.10 | 14.10 | 14.70] 8.80 | 10.00 | 10.00 | 9.40 | 6.70

HT/UF

n 6 2 [ui [ui ie | 13 | 34 | 12 | 23 | 8 | 33 |10 | 2

min 3.03 | 3.09 | 2.90 | 2.98 | 2.91 | 2.66 | 2.76 | 2.74 | 2.69 | 2.99 | 2.84 | 2.95 | 2.92 | 3.61

x 332 | 3.51 | 3.47 | 3.49 | 3.34 | 3.27 | 3.31 | 3.47 | 3.38 | 3.58 | 3.20 | 3.55 | 3.62 | 3.62

max 3.92 | 3.92 | 4.72 | 3.96 | 3.74 | 4.53 | 3.74 | 4.70 | 4.09 | 4.64 | 3.71 | 4.80 | 4.88 | 3.62

sx 013 0.12 | 010 | 0.07 | 011 | 0.08 | 0.08 | 0.12 | 0.08 | 0.11 | 0.07 | 0.20

sd 031 0.51 | 0.32 | 0.26 | 0.46 | 0.30 | 0.47 | 0.41 | 0.40 | 0.31 | 0.39 | 0.64

Vu 8.80 14.60 | 8.80 | 7.60 | 13.70 | 8.90 | 13.40 | 12.10] 11.00 | 9.30 | 10.80 | 17.30

UF/LF

n 6 2 RIT ALU 6 | 16 1489/6335" 1.0) 25 | 28, es io, | 22:

min 0.79 | 1.16 | 0.62 | 0.82 | 0.83 | 0.78 | 0.90 | 0.83 | 0.82 | 088 | 0.01 | 0.01 | 0.90 | 1.09

x 0.98 | 1.341 0.97 | 1.11 | 1.00 | 1.25 | 1.10 | 1.26 | 1.03 | 1.24 | 099 | 1.26 | 1,34 | 1.10

max 110! 152 | 1.34 | 1.32 | 1.23 | 1.63 | 1.58 | 1.73 | 1.26 | 1.60 | 1.23 | 1.73 | 183 | in

sx 0.05 0.04 | 0.05 | 0.03 | 0.06 | 0.06 | 0.04 | 0.04 | 0.04 | 0.14 | 0.05 | 0.08

Sd oil 0.18 | 017 | 012 | 023 | 020 | 021 | 013 | 020 | 0.40 | 0.31 | 0.26

A 10.60 19.00 | 14.90 | 11.20 | 18.70 | 21.10 | 16.80 | 11.90 | 15.50 | 7.40 | 15.60 | 18.40

PPANN

n 6 2 [is fu 14 | 14 | 14 | 3 | 12 | 23 | 8 | 33 |10 | 2

min 1.43 | 149 | 1.22 | 1.29 | 1.33 | 1.33 | 1.34 | 1.35 | 1.46 | 1.47 | 1.52 | 1.46 | 161 | 1.66

< 1.50 | 1.50 | 1.41 | 1.45 | 1.50 | 1.53 | 1.64 | 1.58 | 1.60 | 1.58 | 1.66 | 1.67 | 1.74 | 1.67

max 1.69 | 1.51 | 1.68 | 1.55 | 1.69 | 1.74 | 2.12 | 2.10 | 1.79 | 1.72 | 1.81 | 1.95 | 1.85 | 1.68

sx 0.04 0.02 | 0.03 | 0.03 | 0.02 | 0.07 | 0.03 | 0.03 | 0.01 | 0.04 | 0.02 | 0.02

Sd 0.10 0.10 | 0.08 | 0.11 | o11 | 0.28 | 0.19 | 0.10 | 0.07 | 011 | 0:13 | 0.08

Vi 6.30 6.50 | 5.70 | 6.80 | 7.30 | 16.80 | 12.10| 5.80 | 3.80 | 6.20 | 7.20 | 410

RN/NP

n 6 2 [is [ui | 14 ie | 14 | 34 | 12 | 23 | 8 | 33 | 10 | 2

min 0.49 | 0.64 | 0.45 | 0.48 | 0.50 | 0.56 | 0.47 | 0.46 | 0.37 | 0.45 | 0.46 | 0.47 | 0.42 | 0.58

x 0.66 | 0.65 | 0.59 | 0.63 | 061 | 0.69 | 0.67 | 0.68 | 0.57 | 0.65 | 0.55 | 0.63 | 0.61 | 0.59

max 0.88 | 065 | 0.75 | 0.86 | 0.81 | 0.87 | 0.94 | 0.85 | 0.72 | 081 | 0.70 | 0.93 | 0.68 | 0.60

Sx 0.06 0.02 | 0.03 | 0.02 | 0.02 | 0.04 | 0.02 | 0.03 | 0.02 | 0.03 | 0.02 | 0.03

sd 0.14 0.08 | 0.11 | 0.09 | 0.10 | 0.14 | 0.09 | 0.11 | 0.10 | 0.08 | 0.10 | 0.08

Vi 20.50 12.00 | 16.20 | 13.30 | 13.20 | 19.80 | 13.30 | 17.90 | 15.60 | 13.10 | 14.40 | 13.40

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH,

DuBois & SPLECHTNA

127

69.00

2.61

8.64

12.80

79.17

2.29

7.95

10.30

91.97

114

2.15

12.36

13.50

93.20

424

13.64

15.10

Source : MNHN, Paris

128 ALYTES 11 (4)

le)

9943 140.BÙ Z00L,

Fig. 6. — SEM micrograph of left corner of the oral disk of a graeca tadpole (stage 38) from Krathis

potamos, Greece (NMW 29181).

Through all size classes up to TL <55 mm, mean numbers of MP increase constantly

from 54 to 93 in Greek, and from 67 to 81 in Italian larvae. There are always significant

differences (x <0.1) between Italian and Greek specimens. However, in size classes TL <

45 mm, Italian larvae have more papillae than Greek ones, while in longer larvae the

contrary is observed (Table III).

Inframarginal papillae (IMP) are frequently found in the corners of the mouth or

solitary inside the marginal papillae. Their number is significantly (x <0.01) higher in

Italian than in Greek tadpoles of TL >30 mm (Table IH).

In tadpoles at stages 27 through 41, there are usually 4-5 rows of keratodonts (ooth

rows) in the anterior and 4 in the posterior lip. Keratodonts are disposed in single series

on each ridge. In all tooth rows of tadpoles at stages 36-38, density of keratodonts is 7-8

per 100 pm; they are 70-80 pm long and their apical portions are spatulate with 12-14 acute

marginal denticles each (fig. 7).

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 129

EPA Li / re $

15KU x949 iä.GU 200L;

Fig. 7. — SEM micrograph of keratodonts of a graeca tadpole (stage 38) from Krathis potamos,

Greece (NMW 29181).

The outermost upper row (UTRI) and the outer three lower rows (LTRI-3) are

continuous and almost equal in length. The innermost lower row (LTR4) reveals a short

median gap without exception in our specimens; however, according to BOULENGER

(1891a-b), it may also be continuous. Width of median gap is wide in UTR3-5, and

moderate to short in UTR2 (Table I). Ratios LTR2/LTRI and UTR2P/UTR2I in

Italian and Greek larvae do not differ significantly.

Both lateral extension of upper tooth rows and length of their left and right portion

decrease in centripetal direction; the portions of the innermost extremely short row

(UTRS) bear a few keratodonts only, and may be unilateral or even absent. Absence is

more frequent in, but not restricted to, early developmental stages.

In both Italian and Greek tadpoles, the total number of tooth rows slightly increases

during development. Two tooth row formulae were found frequently: 4/4 (in 30 specimens

of italica and 29 of graeca) and 5/4 (in 53 and 164 specimens, respectively). Two much

rarer formulae were observed exclusively in graeca: one specimen (stage 39) unilaterally

showed a distinct innermost UTR6 (formula 6/4); in five specimens (stages 29, 33, 39, 40,

Source : MNHN, Paris

130 ALYTES 11 (4)

Fig. 8. — Buccal floor of a graeca tadpole (stage 38) from Nea Figalia, Greece (NMW 27637).

41), a short outermost, fifth LTR, one fourth to one tenth of the length of LTRI, was

present in a median position (formula 5/5).

The jaw sheaths (beak) are robust with dark pigmentation; the upper cutting edge is

gently “M”’-shaped, the lower one “U”-shaped; there are about 5 serrations (45-50 im

high) per 100 pm in both sheaths of tadpoles of stages 36-38.

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 131

Fig. 9. - Buccal roof of a graeca tadpole (stage 38) from Nea Figalia, Greece (NMW 27637).

BUCCOPHARYNGEAL CAVITY

In the buccal floor (fig. 8), two pairs of stout, jointed ventral infrarostral pustulations

form a semicircular arch within the median third of the prelingual area. The pair of

prelingual palps is large, with three slender, elongate, finely-limbed, and secondarily

papillate lobes, long enough to reach out of the mouth.

Two slim cylindric lingual papillae rise in the posterior half of the distinct tongue

anlage.

Source : MNHN, Paris

132 ALYTES 11 (4)

The buccal floor arena is scattered regularly with about 100 conical, elongate papillae,

which are almost as long as the lingual papillae; there are few small pustulations in

between. Prepocket papillae can be even larger and furcated or palp-like.

The margin of the velar apparatus describes a smooth, broad arch with three pairs of

conical marginal projections corresponding to the filter cavities; the median portion of the

velum is smooth-edged showing two further papilla-like projections on each side of the

quite undistinct median notch. The glandular zone is broad, not markedly thickened, with

distinct secretory pits; glottis and laryngeal disk are not exposed.

In the buccal roof (fig. 9), the prenarial area shows three pairs of tuberous papillae,

arranged in a semicircular arch; the most anterior pair is polydactylous. The main axis of

the internal nares is almost in a right angle to the main body axis. In the centre of the

anterior narial walls a slender, papillate flap is rising on each side; medially, the wall is

lined with a few minor pustulations. The posterior walls of the nares are smooth-edged

valves with a slight lobe towards the midline on each side. There is a single pair of slender,

elongate postnarial papillae, with a line of pustulations on the anterior margin, and only

one pair of small, cylindric lateral ridge papillae with two or three terminal pustulations

which may be accompanied by two tiny pustules each. The median ridge is forming an

almost isogonic triangular flap; its lateral margins are bordered by three or four

pustulations.

The high number of about 70 buccal roof arena papillae corresponds to that in the

buccal floor, but the dorsal ones are markedly shorter. The dorsal velum is well developed,

showing a broad zone with distinct secretory pits.

No obvious differences were found between Italian and Greek tadpoles.

DISCUSSION AND CONCLUSIONS

MORPHOLOGICAL ADAPTATIONS TO LIFE IN FLOWING WATERS

Most of the tadpoles of graeca and italica on which this study is based were collected

in flowing waters: small brooks, torrents of various sizes or larger rivers (Table I). Only

one series of italica was collected in part in a river (Fiume Savuto) and in part in a pond

in the bed of this river and close to the flowing river itself: probably the eggs were laid

there before the pond was isolated from the river by the lowering of its level.

The larvae of graeca and italica are highly adapted to flowing waters by both external

and buccopharyngeal characters. These comprise the slightly depressed body, the relatively

long tail with low dorsal and ventral caudal fin, the former barely reaching the trunk, as

well as the subterminal oral disk with the highest number of tooth rows among European

ranine larvae.

In the lateral corners of the oral disk, besides the solitary inframarginal papillae, two

papillate ridges are descending towards the basis of the beak on each side (figs. 5-6). In

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 133

this region, folds and additional papillae are often seen in anuran larvae, but distinct pairs

of ridges have not been reported before; they might support the suctorial function of the

oral disk in separating upper and lower “lips”, and thus, possibly enable maintainance of

low-pressure in the posterior portion while the anterior part may be loose. Though the

importance of oral disk suction in flowing waters is evident, too little is known on

mechanics of the peribuccal structures in feeding and adhesion for clear functional

interpretation.

The pair of prelingual palps, long enough to reach out of the mouth, is a feature of

the stream-adapted, bottom-feeding type as characterized by WaAssERSUG (1980).

The number of buccal floor papillae (about 100) is at least twice that of R. temporaria

given by VIERTEL (1982). In European ranine frogs, usually 40 to 60 papillae are found in

this area, the lateral ones tending to be more elongate, the median ones often being low

pustules. In general, these papillae are more numerous and elongate in stream-adapted

larvae feeding on a self-generated suspension, and are serving as a coarse pre-filter

(WaAssERSUG, 1980). This also has been noted by GRADWELL (1972) for tadpoles of Rana

fuscigula which live in “quiet pools in cool mountain streams”.

The larvae of graeca and italica belong to the few lotic European tadpoles which also

include the larva of the Majorcan midwife toad, Alytes muletensis (VIERTEL, 1984), the

tadpoles of R. iberica and R. pyrenaica (SERRA-CoBo, 1993), and possibly at least of some

populations currently referred to R. temporaria and to the R. macrocnemis complex.

As concerns the ecomorphological guilds of exotrophic anuran larvae (ALTIG &

JOHNSTON, 1989), graeca and italica have to be assigned to the lotic, rheophilous type,

moderately expressing the characters of the “clasping” subtype.

COMPARISON WITH OTHER EUROPEAN FROGS OF THE GENUS RAA

In four European brown frog species there is a tendency towards irregular

development of the outermost lower tooth row and the innermost upper tooth row,

concerning UTRS in graeca and italica (present paper), UTRA in R. 1. temporaria, and

UTR3 in À. dalmatina and R. arvalis wolterstorffi (GRiLLITSCH & GRILLITSCH, 1989).

Although early posthatching stages are not on hand, graeca and italica seem to fit into the

general pattern of tooth rows development within the European brown frogs, which

means: rows of keratodonts being additional to the basic formula of 2/3 show retarded

ontogenetic appearance, are added centripetally in the upper, centrifugally in the lower lip,

and reveal the more susceptibility to alterations the later they occur (GRILLITSCH &

GRiLLITSCH, 1989). Both retarded ontogenetic appearance and irregular formation suggest

these additional tooth rows to be of young phylogenetic age.

For differential diagnosis to sympatric R. temporaria, R. dalmatina and green frogs

larvae, the tooth rows formulae of graeca and italica (4-5/4 in italica, 4-6/4-5 in graeca)

appear to be the most suited and easy to handle external character. It may fail in very

young specimens (TL < 20.0 mm) and in advanced specimens with already reduced

number of tooth rows, and then may lead to confusion, especially with R. temporaria.

Source : MNHN, Paris

134 ALYTES 11 (4)

In the samples studied, the following three buccopharyngeal characters of graeca and

italica (stages 36-38) showed distinct differences compared to the other European brown

frog tadpoles for which these characters were already described:

— In ranine frogs, two or four lingual papillae occur, the latter type being most

common (HAMMERMAN, 1964; VIERTEL, 1982; INGER, 1985). According to VIERTEL (1982),

the number of lingual papillae is useful to separate European brown frogs (subgenus Rana

(Rana) sensu Dugois, 1992) from European green frogs (subgenus Rana (Pelophylax)

sensu Dugois, 1992), the former developing four, the latter two lingual papillae. Yet,

graeca and italica tadpoles have two papillae, which contradicts the above classification.

— Comparing the total counts of velar marginal projections, VIERTEL (1982) gives

them as 5-6 in European brown frogs and about 10 in European green frogs; graeca and

italica with a number of 10 match the latter. This cancels the character for group clustering

but separates graeca and italica from the other brown frogs.

— In graeca and italica, the longitudinal axis of the internal nares is almost in a right

angle to the main body axis; this is different from all other European Rana species where

the choanae form an anteriorly opened, obtusely angled “V” (VIERTEL, 1982).

All the characters mentioned above support the proposal of DuBois (1992) to

recognize, within the subgenus Rana ( Rana) s. str., a distinct species group (Rana graeca

group) for graeca and italica.

THE STATUS OF GRAECA AND ITALICA

Larvae from Italy and Greece could not be distinguished unequivocally from each

other on the basis of their buccopharyngeal morphology. However, graeca has a significant

tendency to have more tooth rows in the anterior lip than italica, especially in older stages.

Besides, there are slight but significant differences between them in a variety of external

morphometric features (SV(TL)/stage; ratios VT/HT, UF/LF, VT/SV, SV/SU, RN/NP,

PP/OD, NN/OD; numbers of MP and IMP). Depending on developmental stage these

differences are of variable diagnostic significance. “Coefficients of difference” (GÉRY, 1962;

Mayr, 1975) were calculated for every metric character in all size classes. Out of 70

coefficients, 66 (i.e. 94 %) were low (between 0.0 and 0.71), indicating that thereby less

than 70 % of the individuals can be assigned correctly to one of the groups, Italy or

Greece. Only four coefficients (Table IV) came close to or even surpassed the usual

conventional degree (1.28) of subspecific divergence, suggesting that, with their help,

85-92 % of the individuals can be assigned to the right group. The more the tadpoles

develop, the more evident become the differences between Italian and Greek larvae. The

mean coefficient of difference of all 14 proportions increases from 0.22 (TL 25.0-29.99 mm)

to 0.49 (TL 45.0-49.99 mm).

Discriminant analyses executed for 6 size classes revealed two isolated clusters (Italy

and Greece), to which 87-100 % of the individuals were assigned properly (fig. 10).

This study therefore demonstrates the existence of a significant morphological

dissimilarity between the tadpoles of Italy and Greece. Addition of this third piece of

Source : MNHN, Paris

STAPS Il Fi

4 Il

2 Il ci

: Il G_

1 1 6

Il G

1 1 1 1 1 1 1

-60 -40 0 20 40 60 f (100%)

T +

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2 LE TIII L 6 6 A

3 III I 6 6

1 IITITIIIIIIIGC I GGIGGG GG GC

TITITITIIIIIGG I GGIGGG GG G

1 1 1 Le "1 1 1]

-6 -4 l-2 0 2 “46 (87%)

3 |- =

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Fa G GG G ap AT

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Es 1 1 1 1 1 n

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III GGcGc Fm

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6 4 -2 fo 2 44 6 Goox)

Fig. 10. — Six size classes (A: 20.0-24.99 mm; B: 25.0-29.99 mm; C: 30.0-34.99 mm; D: 35.0-39.99 mm; E: 40.0-44,99 mm; F: 45.0-

49.99 mm) of 212 graeca (G) and italica (1) tadpoles clustered by discriminant analysis with stepwise variable selection. The percentage

of proper assignement is indicated at the right end of the abscissa. Vertical bars (1) at the bottom symbolize class centroids. The ordinate

represents the frequency (number of individuals), the abscissa shows canonical discriminant function scores.

VNLHOHIAS @ SIO4NC ‘HOSLITINO) ‘HOSLITIIO)

SET

Source : MNHN, Paris

136 ALYTES 11 (4)

Table IV. — Ratios and size classes where coefficients of difference between graeca and

italica are close to the usual conventional level of subspecific separation (1.28). For

abbreviations see Table II.

Size class Coefficient of difference

40.00-44.99 mm 1.40

45.00-49.99 mm 1.03

45.00-49.99 mm 1.28

45.00-49.99 mm 1.08

evidence to the first two already available (adult morphology: Dumois, 1987; allozymes:

PICARIELLO et al., 1990; CAPULA, 1991; GOLLMANN, 1992), confirms that both forms should

be treated as different taxons. Should they be considered subspecies or species? Since these

forms are fully allopatric, not connected by a contact zone, this question is difficult to

answer (see e.g. the detailed discussion in Dugois, 1977), and at this stage of research we

prefer to keep this question open. We disagree with several current authors regarding the

taxonomic weight and meaning of “molecular distances” (see Dumois, 1988b: 50, for a

criticism of the use of the name ‘genetic distance” for such indices): these distances can

be based on the results of electrophoreses (e.g. Neïs or Rogers’ distances), on

immunological comparisons, or on nucleic acids hybridizations or direct comparison of

their sequences. Contrary to what is believed by some current workers, including

batrachologists (Cet, 1971; CRESPO, 1972; LANZA et al., 1975, 1976, 1982, 1984; BUSACK et

al., 1985; CapuLA et al., 1985; BusaCK, 1986; etc.), a high “molecular distance” between

two allopatric populations or groups of populations is not by itself sufficient evidence that

they belong to distinct species: it can just be one piece of evidence among others, with no

more weight than evidence from morphology, mating call, chromosomes, etc. As analysed

in detail by PASTEUR & PASTEUR (1980) and PASTEUR (1985), there exists no such thing as

a “specific level” of molecular differentiation: for example, two different good species may

be separated by a “molecular distance” much weaker than that between populations of

another species. Therefore, proper resolution of the status of graeca and italica will require

additional work, dealing with other characters (e. g. hybridization, eco-ethology, mating

calls, nucleic acids, chromosomes, etc.).

RÉSUMÉ

La morphologie externe et l'anatomie buccopharyngée des têtards de Rana [graeca]

graeca et Rana [graeca] italica sont décrites en détail. Ces caractères traduisent une bonne

adaptation de ces têtards à la vie en eau courante. Les particularités buccales les plus

Source : MNHN, Paris

GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 137

notables sont le nombre élevé de rangées de kératodontes, le nombre élevé de papilles sur

le plancher et le plafond buccal, et les grands palpes prélinguaux à lobes allongés.

Les têtards provenant d’Italie ressemblent beaucoup à ceux de Grèce. Toutefois, les

deux groupes s'avèrent différer légèrement mais de manière significative l’un de l’autre

pour un certain nombre de caractères. Ces résultats confirment l'existence de deux taxons

distincts, sous-espèces ou espèces, graeca pour les populations des Balkans et italica pour

celles des Apennins.

ACKNOWLEDGEMENTS

We are indebted to R. WYTEK (Vienna), who essentially contributed to the statistical analysis.

Furthermore, we wish to acknowledge C. BENYR (Vienna) who carefully carried out the measure-

ments, H. C. GRILLITSCH (Vienna) for preparing the total views and the oral disk aspect of the

tadpole, A. OHLER (Paris) for her precious help in the field and in the laboratory, and R. BoUR for

his careful preparation of the tables of this paper for publication. The investigations were supported

by the “Fonds zur Fôrderung der wissenschaftlichen Forschung”, project No. P6353B.

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Morphology, Vienna, 1986, Fortschritte der Zoologie - Progress in Zoology, 35: 276-281.

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zool. ital., (n. s.), 9: 153-162.

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(Amphibia, Plethodontidae). Boll. Zool., 49 (suppl.): 103.

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GRILLITSCH, GRILLITSCH, DUBOIS & SPLECHTNA 139

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Source : MNHN, Paris

Alytes, 1993, 11 (4): 140-154.

Anurans of Borjomi Canyon:

clutch parameters and guild structure

David N. TARKHNISHVILI

Chair of Ecology, Department of Biology, Tbilisi State University,

380077, University str. 2, Republic of Georgia

Spawn clutches of six anuran species, inhabiting Borjomi Canyon in

central Georgia, were examined: Rana macrocnemis, Bufo [bufo] verrucosis-

simus, Pelodytes caucasicus, Rana ridibunda, Bufo viridis and Hyla arborea.

The first three species constitute the guild of “Brown Anura” associated with

forest and have the same spawning mode: females deposit a single clutch per

year. The other three species prefer open areas and have multiple spawns.

Brown Anura have larger eggs, and probably lower fecundity, than other

amphibians of similar body size. Within the Brown Anura guild, different

species show the same relationships of fecundity, egg size and clutch size with

body length. Within the guild, lower fecundity and smaller eggs in species with

smaller body size are compensated by rapid maturation. Among guilds, egg

size is inversely correlated with fecundity.

INTRODUCTION

The reproductive success of amphibians is critically related to their pattern of

spawning. Important variables include fecundity, egg size and total reproductive costs.

Number of eggs per clutch (here and further: fecundity) relates to reproductive success in

terms of the number of offspring, egg size in terms of their quality, reflected in the

survivorship of larvae. Both developmental rates and hatchling size may depend on egg

size (KAPLAN & Cooper, 1984; WaLLs & ALTIG, 1986; WOoDWARD, 1987; ISHCHENKO,

1989; but see WaLLs & ALTIG, 1986; KAPLAN, 1987; WILLIAMSON & BULL, 1989). Perhaps

an increase of reproductive effort may result in a decrease in the survival rates of females,

as in other animal groups (PARTRIDGE & HARVEY, 1985).

For the clutch characters, three alternative ways of adaptation might be favoured: an

increase in egg number per clutch, an increase in egg size or a decrease in total

reproductive effort (if it tends to increase survivorship of adult females). Which way is

favoured will depend on environmental conditions and specific morphology.

GILLER (1984) proposed to divide biological communities in associations including all

coexisting species of the same taxon. Coexisting populations of related species often

exploit similar resources and adapt to the environment in a similar way. In such a case they

might be unified in guilds (ROOT, 1967). Any association may include one or more guilds.

Source : MNHN, Paris

TARKHNISHVILI 141

Still now, no unified methods of dividing communities into guilds exist and intuition plays

an important role (SIMBERLOFF & DAYAN, 1991). If an area is composed of two or more

types of biota (e.g. forest and grassland plots, etc.), the simplest way of outlining guilds

is to unify all species attached to the same type of biota. Spatial preferences could be a

good index of similarity in exploitation of the main resources (food, breeding sites, etc.).

Perhaps species of the same guild are similar not only in utilization of resources, but

also in components of their life cycles, e.g. spawning mode. Connection between guild

structure of associations and divergence of life cycles in coexisting species seems to be a

poorly researched aspect of community ecology.

Six anuran species spread in Georgia appear to be a good example for investigation

of this problem. They are sympatric in many localities. Nevertheless, they could be divided

in two different guilds, according to their biotope preferences. Species of the first guild are

strictly attached to forest during the terrestrial stage of their life. They form isolated, fully

sympatric populations in the small mountain canyons. Species of the second guild prefer

open places even in localities where wooded areas predominate. They form large

populations in the river valleys, penetrating partly into the habitats of the first guild.

The first guild includes Rana macrocnemis, Bufo [bufo] verrucosissimus and Pelodytes

caucasicus. These species will be named here “Brown Anura” in accordance with their

coloration, independent of their taxonomic position. The second guild includes Rana

ridibunda, Bufo viridis and Hyla arborea, named here “Green Anura”. A general

description of the ecology of these species (except B. viridis) in Caucasus was given by

TUNIYEV & BEREGOVAYA (1986).

The aim of the present investigation is the comparative analysis of spawning modes

of these species. The study addresses the questions of which parameters of spawning may

be common to species of the same guild but differ between guilds, and which parameters

are variable within a guild.

MATERIALS AND METHODS

The investigation was conducted in the Borjomi Canyon, Central Georgia. 1 studied

amphibian habitats in the canyon of the river Nedzura (the right tributary of the river

Kura). The stretch of the canyon from the mouth of Nedzura (where a village is located)

to sources of the river exceeds 15 km (fig. 1). Elevation ranges from 900 to 1200 m. Annual

precipitation amounts to 1000 mm. The river is framed by slopes covered with mixed forest

(Abies nordmanianna, Picea orientalis, Fagus orientalis, Carpinus caucasica). The total area

of terrestrial habitats in the canyon reaches about 460 hectares.

About 100 rain pools and pool sites along creeks, ranging from 1 to 3-4 thousands

liters, are used as anuran spawning sites. Size, temperature, lighting and flowing regime of

the different water bodies vary considerably.

Observations were made during April-July 1989-1991. AI water bodies were inspected

on every second to tenth day. Numbers of deposited clutches of each anuran species were

Source : MNHN, Paris

142 ALYTES 11 (4)

Fig. 1. — Investigated part of the river Nedzura canyon (from the village to sources). Dots reflect the

distribution of breeding sites.

counted. The volume of each water body was estimated with the half-ellipsoid volume

equation v = x abc 6! . Tadpole number in all water bodies was estimated just before

metamorphosis, at stages 40-41 (GosnER, 1960). This number was used as approximate

value of metamorphosed offspring. In some pools, the number of tadpoles was estimated

visually. In other cases, up to 1000 tadpoles were stained in Neutral Red solution

(GUTTMAN & CREASEY, 1973), released and recaptured 8-24 hours later. The total number

of tadpoles was estimated with the Petersen method (CAUGHLEY, 1977). The number of

pools where eggs or larvae were eliminated before metamorphosis was also counted.

Nineteen amplexed couples of R. macrocnemis, 21 of P. caucasicus and 29 of B.

verrucosissimus were taken from spawning sites. Each couple was placed in a separate

plastic box containing 3 1 of stream water. After spawning, the following measures were

taken: (1) body length (L = snout-urostyle length) of each female was measured to the

nearest 0.1 mm, using callipers; (2) average diameter of 30 eggs in each spawn clutch (D)

(for this aim, the outer envelope was removed from each egg before the first cleavage; eggs

were transferred to petri dishes containing water; egg cell diameter was measured to an

accuracy of 0.05 mm using a binocular with an eyepiece micrometer); (3) fecundity (N =

number of eggs per clutch); in the small clutches of P. caucasicus eggs were counted

directly, while for the large clutches of R. macrocnemis and B. verrucosissimus the

Source : MNHN, Paris

TARKHNISHVILI 143

following procedure was applied: a portion of each clutch containing 200 eggs with their

envelopes was removed and its volume was measured; the total volume of the clutch was

also measured immediately and, thus, total egg number was calculated; ten females of each

species were killed after spawning for further examination of their ovaries.

Eighty-four naturally deposited clutches of R. macrocnemis, ten clutches each of H.

arborea and B. viridis, and five clutches of R. ridibunda were also studied. In these clutches,

D was measured at stage 9 (GosNER, 1960). Five females of B. viridis and R. ridibunda and

three females of H. arborea were caught just after spawning, killed, and their ovaries were

inspected.

Egg volume (mm), calculated as v = D° x 6‘!, was used instead of D in the basic

calculations. The total volume of clutch V (ml) was calculated as Nv. For estimation of

specific volume of clutch, in comparison with body size of female, I used the index SV =

NL?

Standard methods of correlation and regression analysis (ZAITSEV, 1984) were used for

establishing connections between separate measures. For each data sample, the arithmetic

mean M and the main statistical parameters were estimated. For each compared pair of

samples, the correlation coefficient R was calculated. When interdependence between two

groups of data could be described as linear, parameters of a linear regression y = ax +

b were estimated. When interdependence was clearly curvilinear, parameters of the

allometric equation y = ax° or the hyperbolic equation y = a - bx'! were estimated.

Electivity of females to pools of different volumes was quantified using the electivity index

of IVLEV (1961): J = (P, — P;') (P, + P;'), where P; is the percentage of water bodies of

the given class in the environment and P, is the percentage of spawn clutches deposited in

ponds of this class.

RESULTS

GENERAL DESCRIPTION OF SPAWNING MODES

Brown Anura breed in small water bodies in the forest area. Rana macrocnemis begins

to spawn in early April, and the reproductive period lasts about two weeks. Females spawn

in stagnant or seepage pools, seldom in slowly running creeks. Spawn is deposited as large

clumps floating in water. Pelodytes caucasicus begins to spawn in May or early June, and

the breeding period continues through October. It spawns in slowly running water bodies,

rarely in stagnant pools. Spawn clumps are attached to aquatic vegetation or sunken

objects. Larvae usually hibernate and metamorphose in the second year of their life. Bufo

verrucosissimus begins to breed in April; the breeding period continues through June. It

usually spawns in slowly running water bodies. Sometimes males wait for females in water

as in other species, but more often mating takes place on land. Amplexing couples remain

on the ground surface for up to one week, looking for appropriate breeding sites. If a

satisfactory site is not found, females may spawn on the ground surface. Spawn is

deposited in long cords. There were no visible oocytes in the ovaries of females of Brown

Anura after spawning: each female deposits a single clutch per year.

Source : MNHN, Paris

144 ALYTES 11 (4)

The main breeding sites of Green Anura are situated outside of the studied area, in

the valley of river Kura. They are permanent ponds, often with rich vegetation. In the

study area, Green Anura deposit spawn in warm rain pools. Breeding periods of all three

species continue from mid-April to mid-July. Bufo viridis is the most undiscriminating in

terms of breeding site selection. Rana ridibunda spawns only in the largest pools (500 1 and

more). Oocytes of different size were present in the ovaries of females of Green Anura

having just spawned (except three females of B. viridis): probably each female deposits

some egg portions during the breeding season. Mating occurs in water in all three species.

BODY LENGTH AND FECUNDITY

The body length (L) of breeding females is shown in Table I. It increases in the order

P. caucasicus - R. macrocnemis - B. verrucosissimus in the Brown Anura guild. Average L

of B. verrucosissimus exceeds body length of R. macrocnemis by a factor of 1.6, and the

latter exceeds body length of P. caucasicus also by a factor of 1.6. Number of eggs per

clutch (N) increases between species with body size: R. macrocnemis deposits 3.1 times

more eggs on average than P. caucasicus, and B. verrucosissimus 4.1 times more than R.

macrocnemis (Table 1).

Fecundity also depends on body size within populations. N correlates with L in R.

macrocnemis and P. caucasicus. The highest value of the correlation coefficient R,X was

found in R. macrocnemis perhaps as a result of the high variability in female body length:

Rin = 0.709 (n = 19, P < 0.001; N = 38.5 L - 1267). In P. caucasicus, the correlation

coefficient was: R,X = 0.678 (n = 17, P < 0.001; N = 52.9 L - 1835). Correlation of N

and Lin B. verrucosissimus was not significant : R;X = 0.232, n = 29.

To test the assumption of a common allometric relationship, 1 estimated the

correlation between the logarithms of N and L for a combined sample, including data of

all three species. Correlation of logarithmic data was 0.962 (n = 65, P < 0.0001; N =

0.0136 L?”?) (fig. 2).

BODY SIZE AND EGG SIZE

Species of the Brown Anura guild with larger body size have larger eggs (Table I).

Moreover, correlations between L and D were found within populations. Correlation

coefficients in P. caucasicus and R. macrocnemis populations were 0.669 and 0.800,

respectively. Correlation coefficients of v and L were 0.684 and 0.704 (n respectively 17

and 19, P < 0.001 in both cases; in P. caucasicus, v = 0.137 L - 3.62; in R. macrocnemis,

v = 0.132 L - 4.60). In the B. verrucosissimus population, egg size was not correlated with

female body size: R;y = 0.121.

If data for the three species are lumped together, a clear curvilinear connection

between v and L appears. Correlation of logarithmic data is 0.772 (n = 65, P < 0.001).

Empirically this connection could be satisfactorily described by the hyperbolic equation v

= 7.9 - 230.5 L'' (fig. 3).

Source : MNHN, Paris

TARKHNISHVILI

145

Table I. - Reproductive characteristics of anurans inhabiting Borjomi Canyon. L:

body length (mm); N: number of eggs in the clutch; D: diameter of fertilized

eggs (mm); v: volume of eggs (mm); SV: specific volume of clutch, SV =

VL1, where V = vN; n: sample size; M: arithmetic mean, S: standard

deviation;, SE: standard error; CV: variation coefficient (%). Pc: Pelodytes

caucasicus, Rm: Rana macrocnemis; Bve: Bufo verrucosissimus; Ha: Hyla

arborea; Rr: Rana ridibunda; Bvi: Bufo viridis.

n M S SE CV Limits

Pc 21 44.64 2.13 0.46 4.8 40.5-48.0

Rm 19 71.50 6.62 1.52 9.3 53.3-79.0

Bve 29 113.74 4.85 0.90 4.3 102.6-123.5

Ha L 5 51.9 0.63 0.28 12 51.3-53.1

Rr 20 98.8 2.63 0.59 2.7 92.7-105.2

Bvi 16 81.3 7.94 1.99 9.8 51.9-93.8

Pc 21 493 147 32 29.8 100-750

Rm N 19 1513 377 87 24.9 750-2100

Bve 29 6145 1815 337 29.5 3100-10000

Pc 17 1.69 0.13 0.03 7.6 1.4-2.1

Rm 19 2.11 0.19 0.04 9.1 1.7-2.4

Bve 29 2.22 0.15 0.03 6.9 1.9-2.5

Ha D 10 1.33 0.12 0.03 9.0 1.1-1.6

Rr 5 1.72 0.05 0.02 2.9 1.6-1.9

Bvi 10 1.36 0.10 0.02 7.2 1.1-1.6

Pc 17 0.0141 0.0040 0.0009 28.6 0.004-0.021

Rm sv 18 0.0184 0.0047 0.0012 1 A 0.010-0.032

Bve 29 0.0241 0.0097 0.0032 40.4 0.012-0.046

Source : MNHN, Paris

146 ALYTES 11 (4)

10000: e

500

250

Fig. 2. — Correlation of egg number in clutch and body length of female (only for Brown Anura

guild; logarithmic scale). N: egg number; L: body length (mm). Solid line reflects regression of

N on L: N = 0.0136 L27%, Bve: Bufo verrucosissimus; Pc: Pelodytes caucasicus, Rm: Rana

Source : MNHN, Paris

TARKHNISHVILI 147

mil

60 70 80 90 100 110 120 em

Fig. 3. — Correlation of arithmetic mean of egg size in clutch and body length of female. v: mean

egg volume (mm°); L: body length (mm). v — 7.9 - 230.5 L:! . For Green Anura, only arithmetic

means of values are shown. Bve: Bufo verrucosissimus; Bvi: Bufo viridis; Ha: Hyla arborea; Pc:

Pelodytes caucasicus; Rm: Rana macrocnemis; Rr: Rana ridibunda.

Eggs of Green Anura are smaller than eggs of Brown Anura for animals with similar

body size (fig. 3). Egg size is related to female body size as in the Brown Anura guild. Hyla

arborea has the smallest eggs, R. ridibunda the largest ones (Table I, fig. 3).

EGG SIZE AND FECUNDITY

No correlation between v and N was found within separate Brown Anura

populations. For 84 naturally deposited R. macrocnemis clutches, correlation between v

and N was 0.167, P > 0.05. Linear correlation between N and v exists at the across-species

level (R,n = 0.947, P < 0.001, n = 84, v = 0.661 N - 0.027). Common dependence of

N and v on L provides the basis of this connection.

BODY SIZE OF FEMALE AND VOLUME OF CLUTCH

We can judge variability in volume of clutches only for Brown Anura. In P. caucasicus

and R. macrocnemis populations, a positive correlation between L and V exists (0.862 and

0.828 respectively, n = 17 and 19, P < 0.001). Coefficients of linear regressions of V on

L are 0.218 and 0.345 (fig. 4). In B. verrucosissimus, correlation of L and V is absent, R;4

Source : MNHN, Paris

148 ALYTES 11 (4)

5) Pc

2,54

40 50 60 80 100 L

Fig. 4. — Correlation of body length and clutch volume in Brown Anura guild (logarithmic scale).

V = vN - clutch volume (ml); L: female body length (mm). V = 0.00000171 L*$. Bve: Bufo

verrucosissimus; Pc: Pelodytes caucasicus; Rm: Rana macrocnemis.

Source : MNHN, Paris

TARKHNISHVILI 149

Rm Pc Bve

g (1

+0.25 > —

o f

0.25 R Fe

Ke /

1 23 4 1 234 1 2.3 4

Fig. 5. — Electivity of spawning sites of different sizes. Continuous lines: 1989; dashed lines: 1990.

(1): water bodies of volume to 20 1; (2}: to 160 1 ; (3) to 1280 I; (4) more than 1280 1. Bve: Bufo

verrucosissimus, Pc: Pelodytes caucasicus; Rm: Rana macrocnemis.

= 0.123. Lumping together data of all three species, a curvilinear relation between L and

V was obtained. Correlation of logarithmic values was 0.972 (n = 64, P < 0.001). The

relation V = 0.0000017 L* (fig. 4) shows that clutch volume increases stronger than

female body volume. The allometric relation of N and L is strengthened by a positive

correlation between body size and egg size. For all three species taken together, there is

also a positive correlation between SV and L: R;, sy = 0.501, n = 64, P < 0.001, SV =

0,141 L - 8,66.

EXPLOITATION OF BREEDING SITES AND SPATIAL STRUCTURE OF ANURAN POPULATIONS

The number of available breeding sites appears to be the main factor limiting

population numbers of anuran species. During 1989-1990, spawn was deposited in 188

small water bodies in the study area. The total number of clutches of Brown Anura species

is presented in Table II. Most of the pools dried up or were washed off by rains before

metamorphosis was completed. À few water bodies yielded emergence of most offspring

(Table II). AI Brown Anura species avoided the smallest water bodies and preferred the

largest ones (fig. 5). As a result, spawning often took place in pools already populated with

larvae of other species (Table HIT). In such cases, growth of younger tadpoles was retarded.

Nevertheless, after metamorphosis of older larvae, growth and development of younger

tadpoles renewed and they passed metamorphosis. As a result, even limited numbers of

effective breeding sites in the canyon ensure quite high generation numbers in all Brown

Anura populations.

The situation in Green Anura species is different. In the Nedzura canyon, their

reproductive niches are included fully in the reproductive niche of R. macrocnemis. Large

Source : MNHN, Paris

150

ALYTES 11 (4)

Table II. - Egg and larval mortality in Brown Anura populations. 1: number of water

bodies where spawning took place; 2: total number of clutches deposited in the

canyon; 3: number of breeding sites where metamorphosis was completed; 4:

number of clutches taking part in the formation of the new generation; 5:

approximate number of tadpoles surviving to GOSNER stages 40-41 in all

breeding sites of the canyon; 6: number of tadpoles in breeding sites with lowest

mortality rates (the number of such water bodies is given in brackets), 7:

survival rates from egg to metamorphosis in all sites (%); 8: survival rates in

most effective breeding sites (%). Pc: Pelodytes caucasicus, Rm: Rana

macrocnemis; Bve: Bufo verrucosissimus.

1989 1990

Pc Rm Bve Pc Rm Bve

1 46 56 17 28 89 17

2 410 362 49 331 1037 86

3 10 13 S 13 10 8

4 150 172 14 260 235 72

s 6000 15500 3500 6000 44500 45000

6 4000(1) 13073(2) 3000(3) 4000(1) 35703(3) 40000(1)

7. 4.92 0.83 1.16 6.10 0.92 8.52

8 14.96 11.34 5.42 14.33 19.51 12.52

Table III. - Overlap of breeding sites explored by different Brown Anura species: the

percentage of water bodies already populated with larvae of species B from all

water bodies where spawning of species A took place. Bve: Bufo

verrucosissimus; Pc: Pelodytes caucasicus, Rm: Rana macrocnemis.

A B 1989 1990

Rm Pc 27.3 13.7

Pc Rm 16.7 75.2

Pc Bve 17.4 15.5

Pc Rm, Bve 21.5 84.8

Bve Rm 14.9 18.9

Bve Pc 53.2 17.2

Bve Rm, Pc 65.9 23.1

Source : MNHN, Paris

TARKHNISHVILI 151

tadpoles of this early-breeding species were present in almost all spawning sites of Green

Anura. As a result, larvae of these species were usually eliminated already in early

developmental stages. Emergence occurred only in pools which were not populated with

Brown Anura larvae. Only a few offspring of Green Anura emerged during the year in the

study area: some hundreds B. viridis, some tens H. arborea and a few specimens of R.

ridibunda. This amount is not enough for renewal of Green Anura neighborhoods

populating the canyon. These neighborhoods depend on immigrants from the river Kura

canyon, where large permanent ponds are present and breeding is more efficient.

DISCUSSION

In boreal associations of Anura, species attached to wooded areas (brown frogs, Bufo

bufo complex, etc.) often coexist with species preferring open plots (Rana kl. esculenta

complex, green toad, etc.) (e. g. TUNIYEV & BEREGOVAYA, 1986; PikuLiK, 1985; etc.). Green

frogs and green toads are most widely distributed, penetrating even into urbanized

territories. “Forest” species are commonly early-breeders (BANNIKOV et al., 1977). In

localities where forest areas predominate, they have an advantage in utilization of

spawning sites due to well known priority effects (HEUSSER, 1972; PiKkULIK, 1976; ALFORD

& WicBur, 1985; etc.). For example, Rana sylvatica tadpoles suppress Hyla crucifer

tadpoles when they breed in the same ponds (MORIN & JOHNSON, 1988); Rana temporaria

and Bufo bufo suppress development of Bufo calamita (HEUSSER, 1972; BANKS & BFEBEE,

1987; GRIFFITHS, 1991). In the association described here, “Green Anura” are weak

competitors in small temporary pools, though species of this guild have wider possibilities

of exploitation of large permanent ponds, most of which are situated in open areas.

On the other hand, hot and dry main terrestrial habitats of Green Anura are perhaps

less favourable than humid forest habitats. As a result, Green Anura appear to be stronger

competitors in the terrestrial stage of life whilst Brown Anura are stronger competitors

during larval development.

The common spawning strategy of Green Anura species includes: diminishing of

reproductive costs due to unfavourable terrestrial habitats; perhaps increasing fecundity in

more predictable spawning conditions. Diminishing of reproductive costs is attained via

asynchronous development of oocytes and portional spawning. Portional spawning is

known for many species of Anura distributed in countries with a hot climate (see

DUELLMAN & TRUEB, 1986, for review). Interestingly, R. ridibunda and B. viridis in

northern parts of their range deposit a single clutch during the breeding season (e. g.

KUBANTSEV et al., 1979; PiKULIK, 1985; GOROVAYA & DZHANDAROV, 1986). Increasing

fecundity is attained at the expense of egg size. I have no information about the actual

fecundity of Green Anura in the studied area, but fecundity of H. arborea, R. ridibunda

and B. viridis was investigated in different regions by previous authors. Individual H.

arborea females deposit 744.8 + 45.5 eggs in Czechoslovakia (MORAVEC, 1989) and up to

1000 eggs in Ukraine (SCZERBAK & SCZERBAN, 1980). Rana ridibunda females deposit

4000-12000 eggs in different parts of this species’ range (AVRAMOVA et al., 1976;

KUBANTSEV et al., 1979; GOROVAYA & DZHANDAROV, 1986). A single full clutch of B.

Source : MNHN, Paris

152 ALYTES 11 (4)

viridis found in our study contained about 10000 eggs. In different regions, B. viridis

females deposit 6000-14500 eggs (AVRAMOVA et al., 1976; KUBANTSEV et al., 1979). These

values are significantly higher than those obtained for Brown Anura of comparable body

size. Fecundity of brown frogs and common toads in Europe is also lower than estimates

cited for R. ridibunda and B. viridis (GisBons & MCCARTHY, 1986; READING, 1986).

Allometric interdependence between N and L reflects the fact that N increases with

body volume, not body length: N = aL°, where b + 3. When b < 3, oocyte number

increases slower than body volume; when b > 3, oocyte number increases faster than body

volume. Interestingly, the general allometric index of the relation of N and L obtained for

Brown Anura (2.73) is equal to an analogous value established for the grass frog Rana

temporaria (Gi8BoNs & MCCaARTHY, 1986). This species is ecologically rather similar to R.

macrocnemis. Inversely, in the rice frog ‘’Rana”' limnocharis (characterized by portional

spawning), this index is 3.47 (SHiCHi et al., 1980).

Species spawning in small temporary pools have larger eggs and lower fecundity than

related species which spawn in permanent water bodies (CRUMP, 1981, 1989; WOODWARD,

1987; RAFINSKA, 1991). Accordingly, eggs in Brown Anura species are larger than in Green

Anura of comparable body size. Egg size increases with female body size more rapidly in

this guild (fig. 3). Increase of egg size as well as increase of egg number per clutch are

limited by female body size in both guilds. But among Green Anura, fecundity increases

at the expense of egg size; in Brown Anura, egg size increases at the expense of fecundity.

An additional factor determining the equilibrium point between egg size and fecundity

appears to be environmental temperature. Increase of temperature causes conservation of

high fecundity at the expense of egg size in Bombina orientalis (KAPLAN, 1987). This

dependence may be generalized to the interspecific level. Temperature in the main habitats

of Green Anura species is higher than in the Brown Anura habitats.

Within Brown Anura, differences in spawning mode are connected with female body

size. The choice of the way of adaptation is whether rapid maturation but a small clutch

will be favoured or a large clutch but postponement of maturation. Smaller Brown Anura

species mature in shorter time than larger ones (GOKHELASHVILI & TARKHNISHVILI, in

prep.). Rapid maturation decreases the period between generations and increases the

number of adult animals. On the other hand, body size remains small and fecundity low.

Egg size is also limited. Larger Brown Anura species increase their reproductive effort at

the expense of the period between generations.

The taxonomic position of a species is not connected with its position neither on the

“macrohabitat” nor on the “body size” axes. Both pairs of congeneric species (Rana and

Bufo) are divided among two different guilds.

BEGON et al.(1986) noted that interspecific differences of life cycles often deviate from

the framework of the widely known r-K model. Perhaps the direction of the life cycle

variation between any two species depends on their position in the guild structure of the

community. For our case, species of the same guild vary both in fecundity and egg size but

have a common relation between these characters and female body size. Species of

different guilds have a different correlation between egg size, fecundity and female body

Source : MNHN, Paris

TARKHNISHVILI 153

size. The main reason of interspecific differences within a guild appears to be species-

specific body size, whereas between guilds environmental conditions in the main terrestrial

habitats seem to be important.

ACKNOWLEDGMENTS

Tam greatly indebted to S. TsABADZE and A. CHUBINISHVILI for their help in field work, to R.

MaAMRAD?ZE for her help in the preparation of the manuscript, and to G. GOLLMANN, T. HALLIDAY

and an anonymous referee for their comments on first drafts of this paper.

LITERATURE CITED

ALFORD, R. A. & WILBUR, H. M., 1985. — Priority effects in experimental pond communities:

competition between Bufo and Rana. Ecology, 66 (4): 1097-1105.

AVRAMOVA, O., BULAKHOV, V. & KONSTANTINOVA, N., 1976. — [Characteristics of breeding of tailles

amphibians in Prisamarye]. /n: Voprosi stepnogo lesovedenia à okhrani prirodi, Dnepropetrovsk

{in Russian].

Banks, B. & BEEBEE, T., 1987. — Spawn predation and larval growth as mechanisms for niche

separation in anurans. Oecologia, 72 (4): 569-573.

BANNIKOV, À. G., DAREVSKI, IL. S., ISHCHENKO, V. G, RUSTAMOV, A. K. & SZCZERBAK, N. N., 1977.

— [Guide of amphibians and reptiles of USSR]. Moscow, Prosveshcheniye: i-xxxii + 1-414 [in

Russian].

BEGON, M., HARPER, J. L. & TOWNSEND, C. R., 1986. — Ecology: individuals, populations and

communities. Blackwell Scientific Publications: i-xii + 1-876.

CauGuLey, G., 1977. — Analysis of vertebrate populations. Wiley Interscience Publications.

CrumP, M. L., 1981. — Variation in propagule size as a function of environmental uncertainty for

tree frogs. Amer. Nat., 117 (5): 724-737.

ee 1989. — Egg size variability: consequences to tadpoles. Abstracts 1st World Congr. Herpetol.,

Canterbury, 11-19 Sept. 1989, Canterbury.

DUELLMAN, W. E. & TRUEB, L., 1986. — Biology of amphibians. New York, McGraw-Hill: i-xix +

1-670.

G1BBONS, M. M. & MCCARTHY, T. K., 1986. — The reproductive output of the frog Rana temporaria

(L.) with particular reference to body size and age. J. Zool., (A), 209 (4): 579-593.

GILLER, P. S., 1984. — Community structure and the niche. London, Chapman & Hall.

Gorovaya, V. I. & DZHANDAROV, I. L., 1986. — [Distribution and biology of lake frog in Stavropol

region]. {n: Problemi regionalnoy zoologüi, Stavropol: 25-29 [in Russian].

Gosner, K. L., 1960. — A simplified table for staging anuran embryos and larvae with notes on

identification. Herpetologica, 16: 183-190.

GRIFRITHS, R. A., 1991. — Competition between common frog, Rana temporaria, and natterjack toad,

Bufo calamita, tadpoles: the effect of competitor density and interaction level on tadpole

development. Oikos, 61: 187-196.

GUTTMAN, S. I. & CREASEY, W., 1973. — Staining as a technique for marking tadpoles. J. Herpet.,

7 (4): 388.

Heusser, H., 1972. — Intra- und Interspecifische Crowding-Effect bei Kaulquappen der Kreuzkrôte

Bufo calamita Laur. Oecologia, 10 (1): 93-98.

ISHCHENKO, V. G., 1989. — [Reproductive tactics and demography of amphibian populations]. /n:

ogi Nauki i Tekhniki, ser. Zool. Vertebrates, Moscow, VINITI, 17: 5-51 [in Russian].

IvLEv, V. S., 1961. — Experimental ecology of the feeding of fishes. New Haven, Yale Univ. Press.

KAPLAN, R. H., 1987. — Developmental plasticity and maternal effects of reproductive characters in

the frog, Bombina orientalis. Oecologia, T1 (2): 273-279.

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KAPLAN, R. H. & Cooper, W. S., 1984. — The evolution of developmental plasticity in reproductive

characters: an application of the “adaptive coin-flipping” principle. Amer. Nat., 123 (3):

393-410.

KUBANTSEV, B. S., ZHUKOVA, T. & NIKIFOROVA, T., 1979. — [Reproductive biology of lake frog and

green toad in the Northern Caucasus]. /n: Gerpetologia (collected articles), Krasnodar, Kuban

St. Univ.: 19-36.

Moravec, J., 1989. — Observation on fertilization and oviposition in the European tree frog (Hyla

arborea). Acta Univ. Carolinae, Biologica, edit. 1.6.32: 515-530.

Morin, P. J. & JoHNsoN, E. A., 1988. — Experimental studies of asymmetric competition among

anurans. Oikos, 53 (3): 398-407.

PARTRIDGE, L. & HARVEY, P. H., 1985. — The costs of reproduction. Nature, 316: 20-21.

PiKkuLIK, M. M., 1976. — Growth and developmental rates of R. esculenta and R. arvalis larvae

during their joint development with R. temporaria. Dokladi AN Belorussian SSR, 20 (11):

1048-1050.

_ 1985. — [Amphibians of Belorussia]. Minsk, Nauka i teckhnika: 1-191 [in Russian].

RarNska, A., 1991. — Reproductive biology of the fire-bellied toads, Bombina bombina and B.

variegata (Anura: Discoglossidae): egg size, clutch size and larval period length differences. Biol.

J. Linn. Soc., 43: 197-210.

READING, C. J., 1986. — Egg production in the common toad, Bufo bufo. J. Zool., 208: 99-107.

Roor, R. B., 1967. — The niche exploitation pattern of the blue-gray gnatcatcher. Ecol. Monogr., 37:

317-350.

Snicui, N., SERIZAWA, T. & SERIZAWA, S. H., 1988. — Growth and ovary development of Rana

limnocharis in Kariya-Shi, Aichi Prefecture, Central Japan. Jap. J. Herpet., 12 (3): 95-101 [in

Japanese].

SIMBERLOFF, D. & Dayan, T., 1991. — The guild concept and the structure of ecological communities.

Ann. Rev. Ecol. Syst., 22: 115-143.

S2CZERBAK, N. N. & SZCZERBAN, M. Y., 1980. — Zemnovodnye i Presmykayuszeziesya Ukrainskykh

Karpat. Kiev, Naukova Dumka: 1-268 [in Russian].

TUNIYEV, B. S. & BEREGOVAYA, S. Y., 1986. — Sympatric amphibians of the yew-box groove. /n: N.

B. ANANEVA & L. J. BORKIN (eds.), Systematies and ecology of amphibians and reptiles, Proc.

zool. Inst. Leningrad, 157: 136-151.

WaLLs, S. C. & ALTIG, R., 1986. — Female reproductive biology and larval life history of Ambystoma

salamanders: a comparison of egg size, hatchling size, and larval growth. Herpetologica, 42 (3):

334-345.

WiLLIAMSON, I. & BuLL, C. M., 1989, — Life history variation in a population of the Australian frog

Ranidella signifera: egg size and early development. Copeia, 1989 (2): 349-356.

WoopwarD, B. D., 1987. — Clutch parameters and pond use in some Chihuahuan desert anurans.

Southwest. Nat., 32 (1): 13-19.

Zarrsev, G. N., 1984. — [The mathematical statistics in experimental botany]. Moscow, Nauka: 1-424

{in Russian].

Corresponding editor: Günter GOLLMANN.

Source : MNHN, Paris

Alytes, 1993, 11 (4): 155-163. 155

Summertime population density

of Rana temporaria

in a Finnish coniferous forest

Seppo PASANEN, Pia OLKINUORA & Jorma SORJONEN

Department of Biology, University of Joensuu,

Box 111, 80101 Joensuu, Finland

In this study, two methods were used to determine the distribution and the

density of the frog population in a dry coniferous forest near a site where

thousands of frogs winter in the ponds of a gravel pit. The fence-with-traps

method gives relative values (frogs/100 m/day) and the square method gives

the number of frogs per area. These methods are suitable only for mature and

large immature frogs because small immature frogs (snout to urostyle < 35

mm) were able to climb up along the walls of plastic buckets and fences used

for trapping.

With the square method, 64-80 mature frogs/ha were captured in 1990.

The fence-with-traps method showed that the population density was highest

close to the wintering site (2.3 frogs/100 m/day at a distance of 50 metres) and

decreased with the distance from it (0.17 frogs/100 m/day at a distance of 500

metres). This decrease of density was caused by lower numbers of immature

INTRODUCTION

A wintering and spawning site of the common frog (Rana temporaria, Ranidae) is

located in an old gravel pit in Laikko, Rautjärvi, Finland (61°22’N, 29°17'E), as has also

been mentioned in previous reports published in Finnish (PASANEN et al., 1989, 1990). The

frog winters in Finland almost only in water environment (KOSKELA & PASANEN, 1974).

The habitat of the common frog during its feeding period has been described as a meadow

with luxuriant vegetation composed of tall herbs and grasses (e.g. LOMAN, 1976, 1981,

1984). In Laikko, however, dry coniferous forest surrounds the ponds of the gravel pit

where thousands of frogs winter and spawn. The nearest potential wintering and spawning

sites are the lakes 700 metres from the gravel pit.

LOMAN (1976, 1981, 1984) has used the capture-recapture method for studying the

densities of frog populations. The fence-with-traps method has been used to count

migrating frogs in spring or in autumn (KOSKELA & PASANEN, 1974; PASANEN et al., 1989,

1990). The main material for this study was gathered using the fence-with-trap method.

This method gives values of relative population density (e.g. frogs/100 m/day). The aim of

this study was to determine population density at different distances from the wintering

site. In 1990 also the square method was used to determine population density as frogs/ha.

Source : MNHN, Paris

156 ALYTES 11 (4)

Table I. — Distances of the fences and of the squares from the wintering site of Rana

temporaria, lengths of the fences and numbers of trapping days in 1989 and 1990.

Distance Distance

MATERIAL AND METHODS

In the study area, frogs spawn usually at the end of April or in the beginning of May,

and the migration to the wintering site takes place in September and October. In the spring

of 1989, when they started to move from the wintering and spawning pond, 2042 (977

mature and 1065 immature) frogs were marked collectively by toe-clipping. In 1989, four

fences-with-traps (KOSKELA & PASANEN, 1974) were built to study the dispersion of frogs

from the gravel pit (fig. 1, Table I). The fence was made of a 30 em high plastic sheet

stretched vertically between wooden sticks without any horizontal part on the top. The

lower edge of the sheet was covered by moss to provide a tight seal against the ground.

Buckets (diameter 25 cm, depth 22 cm, angle 95°) were buried into the soil at 10 m

intervals along the fence which crossed in the middle of the buckets, so that frogs from

both sides were able to fall into the buckets.

The total trapping period in 1989 lasted from the end of May to the beginning of

August. The buckets were examined and emptied almost every other day. In 1990, only

fences I and II were used during June-July.

AII frogs caught in the buckets during summer were measured (from the snout to the

end of the urostyle). The material was grouped as follows: immature specimens (length

smaller than 64 mm) and mature individuals (length greater than 64 mm) according to

KosKELA & PASANEN (1974). The frogs were marked collectively by toe-clipping (the same

toe for all summer captures, but not the same toe as in the spring) and the adults were also

sexed. The frogs were then set free 2-3 metres from the pitfall haphazardly on either side

of the fence. The results are given as number of frogs per 100 metres of fence in 24 hours

(frogs/100 metres/day).

In June 1989, seven 10 X 10 metres squares were built at the distance of 350-400

metres from the wintering pond between the fences II and II (fig. 1). The fence was again

30 centimetres high and every square had one bucket in each corner.

Source : MNHN, Paris

PASANEN, OLKINUORA & SORJONEN 157

s A

CRRRRE RE ERRE EN OR À

CL A wintering A

oO Se

A Sa

A,B,C

Fig. L. — Map of the study area.

I-IV = fences-with-traps (buckets placed at 10 m intervals).

A-C = fenced squares (50 x 50 m, 36 buckets}*.

K = square without fence (16 buckets)*.

Sm = small squares (10 x 10 m).

* The small inset figure shows the location of buckets in squares A-C and K.

Source : MNHN, Paris

158 ALYTES 11 (4)

Frogs/100m/day

3 _

male Nfemale Climmature

2.5 2.3

2+ 1.91

1.5 + 1.38

1+ 0.91 0.85

0.57

0.5-

0 F > = FT

17-89 11/-89 1117-89 1V/-89 1/-90 11/-90

immature 2.15 1.46 0.68 0.44 1.32 0.7

female 0.05 0.35 0.15 0.04 0.01 0.03

male 0.1 0.1 0.08 0.09 0.05 0.12

Fig. 2. — Frogs caught with the fence-with-traps method in 1989 and 1990 on fences I-IV (see

fig. 1).

In the beginning of June 1990, three 50 X 50 metres enclosures (A-C) were built to

count natural frog density (fig. 1, Table I). The plastic fence was 50 centimetres high and

the lower edge of the fence was buried 10 centimetres into the mineral soil. In each square,

20 buckets were buried along the fence (inside), and the inner part of the square was

furnished with 16 buckets placed at a 10 m distance from each other. The control plot

consisted of 16 buckets without a fence (square K) (see fig. 1).

Frogs were trapped in squares and at fences I and IT from June 2 to August 10, 1990.

The buckets were checked and emptied and the frogs were treated as in the previous

summer. During autumn (September 18 — November 3, 1990), frogs began to gather into

the side buckets of the squares on their way to the wintering sites. These frogs were

counted and released outside the square. A total of 36 recently metamorphosed frogs were

marked to control their possible crossing of a fence.

Weather conditions (temperature and humidity) were recorded with a Lambrecht-

hydrothermograph during both summers. Mean daily temperature and mean daily relative

humidity were calculated as the mean of four observations (00.00, 08.00, 16.00, 24.00 h)

of the day before the catching day.

Source : MNHN, Paris

PASANEN, OLKINUORA & SORJONEN 159

Table II. — Proportion of adults among frogs marked in the spring 1989 (977 mature,

1065 immature) and caught during the summer at fences I-IV.

Fence number Recaptured Percentage of adult

(mature/immature) marked frogs

8/60

6/23

16/20

6/8

RESULTS

The total number of frogs caught in the summer of 1989 was 555 (85 mature and 470

immature). The number of immature frogs decreased significantly (Pearson’s correlation,

R? = 12.36, P < 0.01) as the distance from the wintering site increased (fig. 2). Most

females were caught at fences IT and III, while the number of male frogs was nearly the

same at all four fences. In 1990, the actual number of captured frogs was 133 (10 mature

and 123 immature).

The proportion of adult frogs marked in the spring of 1989 at the wintering site

increased with increasing distance from the gravel pit (Table II). Of the 555 frogs caught

and marked at fences I-IV in the summer of 1989, only 29 individuals (5%) were

recaptured in the same summer and none in 1990. Recaptures were more common among

adults (14 %) than among immature frogs (3 %).

In the small squares (10 X 10 metres), 0-2 mature frogs were found per square (mean

= 1.29, S.E. = 0.29, n = 7), which would make 129 frogs/hectare. In the large (A-C)

squares, 10-17 frogs/square were caught in summer and 16-20 in autumn (Table III). AI

frogs marked inside the squares during summer and three to six unmarked frogs/square

were found in the autumn. They did not fall into the traps during summer, even though

the trapping period lasted 40-42 days. The total number of mature frogs/ha varied from

64 to 80.

Small immature frogs (juveniles in their first year, snout to urostyle < 35 mm) were

able to climb up along the walls of the plastic buckets and fences. This was indicated by

the marked frogs and the increase in the number of immature frogs caught during summer.

Eight (24 %) of the 36 small frogs marked in autumn and released outside the squares were

found again inside a square later on. In the summer (at the beginning of metamorphosis),

only 3-11 small frogs were found in the squares (12-44 immature/ha), but, during the

autumn trapping, 140-190 small, recently metamorphosed frogs were captured per square

(560-760 immature/ha). Although this method proved to be unsuitable for density

Source : MNHN, Paris

160 ALYTES 11 (4)

Table III. — Number of mature frogs in the squares.

Summer = catches in summer (including buckets along the fence and in the inner part

of the square).

Autumn = catches in autumn.

Inner buckets = catches in the buckets in the inner part of the square in summer

(number of catching days in parenthesis).

Summer

Inner

buckets

6 (42)

8 (40)

5 (40)

1 (4)

estimation of the smallest frogs, it shows that in the autumn the immature frogs are

abundant at a distance of hundreds of meters from their home pond.

No correlation was found between the activity of the frogs and weather conditions.

Temperature apparently did not influence the activity of frogs during summer (1989 R? =

1.53, P > 0.60; 1990 R? = 1.76, P > 0.60), nor did relative humidity (1989 R? = 4.20,

P > 0.40; 1990 R? = 10.94, P < 0.25).

DISCUSSION

The fence with traps method is generally used to study frog migrations in the spring

or autumn. In this study, we tried to use the method also to study the distribution and

population structure. The method gives only relative results, but when several fences are

used at the same time, the results are comparable. In this study we got clear results: the

number of immature frogs decreases as distance from the wintering site increases, but

equal numbers of mature frogs were found at different distances (fig. 2).

We used the square method in order to estimate the population density. These results

(64-80 mature frogs/ha) agree with those of other studies. On meadows, the population

density of Rana temporaria can be as high as 550-790 mature frogs/ha (LOMAN, 1976, 1981,

1984). In deciduous forests, it has been estimated that there are 125 mature frogs/ha

(GLowaciNski & WirkoWski, 1970), and in coniferous forests 25-50 adult frogs/ha

(INOZEMTSEV, 1969). The method used in the cited studies was capture-recapture. In the

present study, a density of 100 frogs/ha is reached, if large immature frogs are included

Source : MNHN, Paris

PASANEN, OLKINUORA & SORJONEN 161

(frogs longer than 64 mm were considered to be adults). Since the ground vegetation in

Laikko is very poor and includes in many areas only mosses, the population density seems

to be rather high for these conditions. In 1989 and 1990, nearly 3000 mature frogs were

found to winter in the ponds at Laikko (PASANEN et al., 1989, 1990). If the population

density around the gravel pit in summer remained constant (64-80 frogs/ha), 3000 frogs

would require an area with a radius of 350-400 m.

In areas around a spawning pond, favourable conditions during spawning and the

larval phase have a strong impact on population density (SAVAGE, 1961; LoMAN, 1978;

Cummins, 1986). In Laikko, the ponds in the gravel pit are the only spawning places of

the area. According to the density results, the number of frogs, especially young ones,

decreases as the distance from the ponds increases. Of all the marked frogs, the proportion

of mature frogs was greater as the distance from the wintering site increased. This indicates

that the spawning and wintering site is the core of the population, from which immature

frogs gradually move farther away.

This type of population is quite vulnerable. Spawning failure in one spring is not as

dramatic as is failure to winter. Wintering may be unsuccessful due to draining of the

pond, for example, and this can cause the population to collapse for a long time. Catches

for the years 1989 and 1990 were different: in 1989, there were many more immature and

female frogs than in 1990 (fig. 2). This raises the question: is it possible that frogs —

especially female and immature frogs — could also winter on the ground, when the soil

doesn't freeze deeply?

In square K were captured only one mature frog, while in the corresponding buckets

of the inner part of squares A-C there were 5-8 frogs. Obviously the fence confuses the

frogs, and a 50 X 50 m square is therefore too small for studying their movements. On

the other hand, many frogs do not move enough during the whole summer to fall into a

bucket (Table III).

The square method is good for estimating population density of the frogs. With 10

x 10 m squares, mere chance determined whether there were two frogs, one frog or none

inside a square. Squares of 50 X 50 m, however, seemed to be suitable in this biotope.

When population density is high, it may also be possible to obtain reliable results with

smaller squares. We recommend to build squares in late summer and to do empty-catching

during the autumn migration of the frogs; no buckets are needed in the inner part of the

square. The observation that young frogs which have not yet wintered are able to climb

over a plastic fence and up the sides of a bucket decreases the usefulness of these methods,

which are suitable only for mature and larger immature (> 35 mm) frogs.

In many studies, correlations between temperature and humidity and the activity of

frogs were observed (BELLIS, 1962; DoLr, 1965; AsHBy, 1969; LOMAN, 1979; WOOLBRIGHT,

1985). In this study, we could not find any correlation between weather conditions and

movements of the frogs. A possible explanation is that the buckets were usually examined

every second day and the long period between examinations covered the correlation. Thus

the buckets ought to be examined at least once a day.

Source : MNHN, Paris

162 ALYTES 11 (4)

RÉSUMÉ

Dans cette étude, deux méthodes ont été utilisées pour déterminer l’activité et et la

densité d’une population de grenouilles dans une forêt de conifères assez sèche près d’un

site où des milliers de grenouilles hivernent dans les étangs d’une gravière.

La méthode qui fait appel à des pièges placés le long d’une barrière donne des valeurs

relatives (grenouilles/100 m/jour). La méthode des carrés donne le nombre des grenouilles

par surface. Ces méthodes ne conviennent que pour l'étude des grenouilles de taille

importante, car les petits spécimens encore immatures (< 35 mm) sont capables de

grimper le long des seaux en plastique et le long des barrières utilisées pour les piéger.

En 1990, avec la méthode des carrés, 64 à 80 grenouilles matures ont été piégées par

hectare. La méthode des barrières a démontré que la densité de la population était la plus

grande près du site d’hibernation (2,3 grenouilles/100 m/jour à une distance de 50 mètres),

et que cette densité diminuait avec l’augmentation de cette distance (0,17 grenouilles/100

m/par jour à une distance de 500 mètres). La baisse de la densité totale est causée par une

diminution de la densité des jeunes grenouilles quand la distance augmente.

LITERATURE CITED

Asusy, K. R., 1969. — The population ecology of a self-maintaining colony of the common frog

(Rana temporaria). J. Zool. Lond., 158: 453-474.

BeLLis, E. D., 1962. — The influence of humidity on wood frog activity. Am. Midl. Nat., 68: 139-148.

Cummins, C. P., 1986. — Interaction between the effects of pH and density on growth and

development in Rana temporaria L. J. anim. Ecol., 55: 303-316

Dore, J. W., 1965. — Summer movements of adult leopard frogs, Rana pipiens Schreber, in northern

Michigan. Ecology, 46 (3): 236-255.

GLOWAGINSKI, Z. & Wirkowski, K., 1970. — Number and biomass of amphibians estimated by

capture and removal method. Wiadomosci ekologiczne, 16: 328-340. [In Polish, with English

summary].

INOZEMTSEV, A. A., 1969. — The trophic relations between the frogs in the coniferous forests of

Moscow. Zool. Zhur., 48: 1687-1694. [In Russian, with English summary].

KOSKELA, P. & PASANEN, S. 1974. — The wintering of the common frog, Rana temporaria L., in

northern Finland. Aquilo, (Zool.), 15: 1-17.

LOMAN, J., 1976. — Fluctuations between years in density of Rana arvalis and Rana temporaria. Norw.

J. Zool., 24: 238.

--- 1978. — Growth of brown frogs Rana arvalis Nilsson and Rana temporaria L. in South Sweden.

Ekol. Pol., 26 (2): 287-296.

ar 1979, — Annual and daily locomotor activity of the frogs Rana arvalis and R. temporaria. Brit.

J. Herpet., 6: 83-85.

- 1981. — Spacing mechanisms in a population of the common frog, Rana temporaria during the

non-breeding period. Oikos, 37: 225-227.

--- 1984. — Density and survival of Rana arvalis and Rana temporaria. Alytes, 3 (4): 125-134.

S., SORJONE GÜNTHER, O., MARTIKAINEN, S., OLKINUORA, P. & KANTONEN, P. 1990.

— Laikon sammakot. Pohjois-Karjalan Luonto, 18: 41-45.

S., SORJONEN, J., KANTONEN, P. & PEIPONEN, J. 1989. — Tuhansien sammakoiden

talvehtimiskeko. Pohjois-Karjalan Luonto, 17: 28-30.

Source : MNHN, Paris

PASANEN, OLKINUORA & SORJONEN 163

SAVAGE, R. M., 1961. — The ecology and life history of the common frog (Rana temporaria

temporaria). London, Pitman.

WooLBrIGHT, L. L., 1985. — Patterns of nocturnal movement and calling by the tropical frog

Eleutherodactylus coqui. Herpetologica, 41 (1): 1-9.

Corresponding editor: Günter GOLLMANN.

Source : MNHN, Paris

Alytes, 1993, 11 (4): 164. Announcement

Workshop on

population biology of amphibians

A workshop entitled “Population biology of amphibians” will be held in Vienna

(Austria) from Wednesday 14“ to Saturday 17 September 1994. Round table discussions

on the topics “Demography of amphibian populations” and “Dispersal and gene flow

among amphibian populations” will be the main events of the workshop. Poster

presentations on all aspects of amphibian population biology will be welcome. The

program will also include a few invited lectures and an excursion.

The workshop will be jointly organized by the Austrian Academy of Sciences, the

International Society for the Study and Conservation of Amphibians (ISSCA) and the

Osterreichische Gesellschaft für Herpetologie (ÔGH, the Austrian Herpetological Society).

Persons interested in participating should contact Dr. Walter HôbL or Dr. Günter

GOLLMANN, both at the Institut für Zoologie der Universität Wien, AlthanstraBe 14, 1090

Wien, Austria (fax: (+431) 31336 700).

The 1994 General Meeting of ISSCA will be held in Vienna during this workshop (on

Friday 16 September). For information, please contact Dr. Alain Dugois, ISSCA

General Secretary, Laboratoire des Reptiles et Amphibiens, Muséum national d'Histoire

naturelle, 25 rue Cuvier, 75005 Paris, France.

Source : MNHN, Paris

AINTES

International Journal of Batrachology

published by ISSCA

EDITORIAL BOARD FOR 1993

Chief Editor: Alain Dusois (Laboratoire des Reptiles et Amphibiens, Muséum national d'Histoire

naturelle, 25 rue Cuvier, 75005 Paris, France).

Deputy Editor: Günter GOLLMANN (Institut für Zoologie, Universität Wien, AlthanstraBe 14, 1090

Wien, Austria).

Other members of the Editorial Board: Ronald G. ALriG (Mississippi State University, U.S.A.);

Emilio BALLETTO (Torino, Italy); Stephen D. Busack (Ashland, U.S.A.); Alain COLLENOT

(Paris, France), Tim HaLuIDAY (Milton Keynes, United Kingdom); W. Ronald HEYER

(Washington, U.S.A.); Walter HôDpz (Wien, Austria); Pierre JoLY (Lyon, France), J. Dale

ROBERTS (Perth, Australia); Petr RorTH (Mëlnik, Czech Republic); Ulrich SiNscH (Koblenz,

Germany); Marvalee H. Wake (Berkeley, U.S.A.).

Technical Editorial Team (Paris, France): Alain DuBois (texts); Roger Bour (tables); Annemarie

OHLER (figures).

Index Editors: Annemarie OHLER (Paris, France) : Stephen J. RICHARDS (Townsville, Australia).

GUIDE FOR AUTHORS

Alytes publishes original papers in English, French or Spanish, in any discipline dealing with

amphibians. Beside articles and notes reporting results of original research, consideration is given for

publication to synthetic review articles, book reviews, comments and replies, and to papers based

upon original high quality illustrations (such as color or black and white photographs), showing

beautiful or rare species, interesting behaviors, etc.

The title should be followed by the name(s) and address(es) of the author(s). The text should

be typewritten or printed double-spaced on one side of the paper. The manuscrit should be organized

as follows: English abstract, introduction, material and methods, results, discussion, conclusion,

French or Spanish abstract, acknowledgements, literature cited, appendix.

Figures and tables should be mentioned in the text as follows: fig. 4 or Table IV. Figures should

not exceed 16 X 24 cm. The size of the lettering should ensure its legibility after reduction. The

legends of figures and tables should be assembled on a separate sheet. Éach figure should be

numbered using a pencil.

References in the text are to be written in capital letters (SOMEONE, 1948; So & So, 1987;

EveryBopY et al., 1882). References in the literature cited section should be presented as follows:

BouRRET, R., 1942. - Les batraciens de l'Indochine. Hanoï, Institut Océanographique de l’Indochine:

i-x + 1-547, pl. I-IV.

GRAF, J.-D. & PoLLs PELAZ, M., 1989. - Evolutionary genetics of the Rana esculenta complex. In:

R. M. DAWLEY & J. P. BOGART (eds.), Evolution and ecology of unisexual vertebrates, Albany, The

New York State Museum: 289-302.

INGER, R. F., VorIs, H. K. & Voris, H. H., 1974. - Genetic variation and population ecology of some

Southeast Asian frogs of the genera Bufo and Rana. Biochem. Genet, 12: 121-145.

Manuscripts should be submitted in triplicate either to Alain Dumois (address above) if dealing

amphibian morphology, systematics, biogeography, evolution, genetics or developmental

biology, or to Günter GOLLMANN (address above) if dealing with amphibian population genetics,

ecology, ethology or life history.

Acceptance for publication will be decided by the editors following review by at least two

referees. If possible, after acceptance, a copy of the final manuscrit on a floppy disk (3 4 or 5 4)

should be sent to the Chief Editor. We welcome the following formats of text processing: (1)

preferably, MS Word DOS and Windows, WordPerfect (4.1 to 5.1) or WordStar (3.3 to 5.5); (2) less

preferably, formated DOS (ASCII) or DOS-formated MS Word for the Macintosh.

No page charges are requested from the author(s), but the publication of color photographs is

charged. For each published paper, 25 free reprints are offered by Alytes to the author(s). Additional

reprints may be purchased.

Published with the support of AALRAM

(Association des Amis du Laboratoire des Reptiles et Amphibiens

du Muséum National d'Histoire Naturelle, Paris, France).

Directeur de la Publication: Alain Dumois.

Numéro de Commission Paritaire: 64851.

Alytes, 1993, 11 (4): 117-164.

Contents

Britta GRiLLITSCH, Heinz GRiLLITSCH, Alain Dugois & Heinz SPLECHTNA

The tadpoles of the brown frogs Rana [graeca] graeca and

Rana [graeca] italica (Amphibia, Anura) .............................. 117

David N. TARKHNISHVILI

Anurans of Borjomi Canyon:

clutch parameters and guild structure .................................. 140

Seppo PASANEN, Pia OLKINUORA & Jorma SORJONEN

Summertime population density of Rana temporaria

AT AMENER CONTE OUS OS eee Ce net 155

Announcement

Workshop on population biology of amphibians ....................... 164

Alytes is printed on acid-free paper.

Alytes is indexed in Biosis, Cambridge Scientific Abstracts, Current Awareness in Biological

Sciences, Pascal, Referativny Zhurnal and The Zoological Record.

Imprimerie F. Paillart, Abbeville, France.

Dépôt légal: 4°" trimestre 1993.

Source : MNHN, Paris