L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 6. 1991 (Budapest, 1991)

Gubányi, A.; Pekli, J.: Contribution to the knowledge of green frog populations (Rana esculenta complex, Anura, Amphibia) of the Kis-Balaton Landscape Protection Area, Hungary

The LDH-B isozyme patterns have been intensively investigated in different parts of Europe (UZZEL & BERGER 1975 for review). Based on the results of the years 1989-1990 Li and Rs alleles were the most common. This was different from the allele frequency of the investigated L-E or R-E populations. For LDH, two alleles (Li,Ls) were common in R. lessonae in these three samples. U was more common. It occurred at frequencies between 0.56-0.76 (Table 1). The corresponding frequencies in R. esculenta specimens varied between 0.36-0.50. On the other hand the third lessonae allele (Ls) was not manifested in our samples. Rf allele, which is very common in Poland and Germany, was present less frequently and only in heterozygous forms with lessonae alleles in this region. But one individual consisted of Rf and Rs ridibunda alleles in heterozygous form, which also was morphologically R. ridibunda in the Kis-Balaton Reservoir

. The L-E population system suggested by present data for the three sample sites at the Kis-Balaton Landscape Protection Area don't agree with the results found in Diás island in 1987 (GUBÁNYI 1988, LOW et al. 1989). The R« and Rf ridibunda alleles had been determined in both homozigous and heterozygous form, while Rs ridibunda allele occurred only in heterozygous form with Lj lessonae allele in female R. esculenta specimens in later Diás island samples. On the other hand malei?. esculenta at this sampling area was not found in 1990. But they might exist in the River Zala and in canals situated nearby. If we take the results of earlier investigation into consideration it seems, that the mixed lessonae-esculenta-ridibunda population may be formed either by contacting of two different biotopes or by mating of R. esculenta individuals among themselves, which results in infertile R. ridibunda offsprings. The former idea is supported by the investigation of DELY at the River Zala in 1951 (G.O. DELY, pers. comm.), who identified adult R. esculenta and R. ridibunda specimens along the river bank. Different distribution of R. lessonae and R. esculenta (Fig. 1) among sampling sites points out, that anthropogenic effects may influence the population structure of water frogs in favour of R. esculenta. BERGER (1987) had the same findings in Poland. REFERENCES BERGER, L. (1966): Biometrical studies on the population of green frogs from the environs of Poznan. - Ann. Zool., 23: 303-324. BERGER, L. (1967): Embryonal and larval development of Fi generation of green frogs of different combinations. - Acta Zool. Cracov., 12:123-160. BERGER, L. (1968): Morphology of the Fi generation of various crosses within Rana esculenta complex. - Acta Zool. Cracov., 13: 301-324. BERGER, L. (1970): Some characteristics of crosses within Rana esculenta complex in postlarval development. - Ann. Zool Cracov., 27: 373-416. BERGER, L. (1971): Sex ratio in the Fl progeny within forms oiRana esculenta complex. - Genet. Polon., 12: 87-101. BERGER, L. (1973): Systematics and hybridization in European green frogs of Rana esculenta complex. -/. Herpetol., 7:1-10. BERGER, L. (1987): Impact of agriculture intensification on Amphibia. In: J.J. VAN GELDER & H. STRIJBOSCH (eds): Proceedings of the 4th Ordinary General Meeting of the Societas Europaea Herpetologica, Nijmegen: 79-82.