L. Forró szerk.: Miscellanea Zoologica Hungarica 10. 1995 (Budapest, 1995)

Gubányi, A.: Biometrical investigation of water frogs in the Szigetköz Landscape Protection Area

When testing the morphometric indices, included into identification function key, sexual dimorphism has not been found using by Mann-Whitney U-test (P>0.05). Based on regression and determination coefficients the two indices proved to be independent from each other. Discussion Rana lessonae - Rana kl. esculenta population systems have mostly (99 %) been found in the floodplain of River Danube (Szigetköz). Mean values of morphometric characters of water frog forms, with the exception of male Rana lessonae, were lower than the values of frogs collected in other part of Hungary (cf. Gubányi 1992). Mean values of Rana lessonae specimens generally were lower than the data of frogs, collected in the vicinity of Gabcikovo (Lác 1959) situated on the other side of the River Danube. However, maximum values of morphometric characters for Rana lessonae specimens were higher in Szigetköz. As Figs 1-3 showed, distribution pattern of morphometric characters of the two water frog forms represented normal distribution, except inner metatarsal tubercle for both forms and first toe length for female Rana kl. esculenta specimens. These results were in controversy with the frequency distribution data of body length published by Berger (1966), showing characteristic features of multiple peaked curves. Independence of the two indices, included the identification function, could arise the information bases of the key. As mentioned in the introduction, according to Wijnands & Gelder (1976) two indices BL/IMTL and BL/IMTW can discriminate the three water frog forms at high level from each other. However, the measurement of IMTW from technical point of view is a bit complicated, thus the indices applied by me seem to be more suitable for field work. Allometric growth rate, which was detected after transforming the measurements into linear forms, also supported the use of indices, because the growth rate of the investigated morphometric characters cannot represent any symmetry, i.e. they have not isometric growth. References Berger, L. (1964): Is Rana esculenta Camerano a distinct species? - Ann. Zool., Warszawa 22(13): 45-61. Berger, L. (1966): Biometrical studies on the population of green frogs from the environs of Poznan. - Ann. Zool. Warszawa 23(11): 303-324. Berger, L. (1970): Some characteristics of the crosses within Rana esculenta complex in postlarval development. - Ann. Zool. Cracov. 27: 373-416. Boulenger, G. A. (1885): A description of the German river frog, Rana esculenta var. ridibwula Pall. - Proc. Zool. Soc. London 1885: 661-671. Boulenger, G. A. (1891): A contribution to the knowledge of the races of Rana esculenta and their geographical distribution. - Proc. Zool. Soc. London 1891:374-384. Graf, J. & Pelaz, P. (1989): Evolutionary genetics of the Rana esculenta complex. - In: Dawley, R. M. & Bogart, P. (eds). Evolution and Ecology of Unisexual Vertebrates, New York State Museum Bulletin 466: 289-301. Gubányi, A. (1992): Investigation of Population-structure, biometrics and growth of water frogs for establishment of frogculture. Ph.D. Thesis, GATE, Gödöllő. 110. pp. [in Hungarian] Gubányi, A. & Creemers, R. (1994): Population structure of water frogs in a floodplain of the River Danube (Szigetköz) in Hungary. - Zool. Pol. 39(3-4): 457-461. Gubányi, A. & Korsós, Z. (1992): Morphological analysis of two Hungarian water frogs {Rana lessonae-esculenla) populations. - Amphibia-Reptilia 13: 235-243.