Geographic variation in the characteristics of Rana temporaria metamorphs

Abstract

Geographical differences and the structure of intrapopulation phenotypic variation in metamorphs’ life-history traits from 6 spatially distant populations of Rana temporaria were studied. In frogs from northern populations, heritability of larval period duration, growth rate, and size at metamorphosis was relatively low. Growth rate and size at metamorphosis in laboratory frogs were significantly higher than in those collected in nature, whereas the larval period, in turn, was lower. The revealed differences within and between populations represent a counter-gradient variation. The genetic and phenotypic correlations by pairwise comparisons these three traits were similar (both in magnitude and sign) in all populations, with the exception of one population from Kamchatka. This population was successfully introduced 10 years ago from the Moscow region to the habitat with the minimal duration of activity season. The genetic correlation between body size at metamorphosis and larval period was significantly negative. Thus the response to shortening of activity season was not only the growth rate increase but decrease in larval period, partially at the expense of metamorph size. Refs 6. Tables 2.