Contribution to the biometry of some Argentine species of the genus Telmatobius

Abstract

The biometrical study of samples belonging to the north-western Argentinian Telmatobius populations, (ie. T. marmoratus subsp.,T. atacamensis Gallardo, T. h. hauthali Koslowsky, T. hauthali schreiteri Vellard, T. barrioi Laurent and T. ceiorum Laurent) shows that three ecogeographical groups can be distinguished. A northern group of high altitude (marmoratus and atacamensis) which as, it seems, a better aquatic adaptation. A southern group of somewhat lesser altitude (authali and schreiteri), is still much more aquatic than terrestrial and accordingly has larger webbing.

The frogs of the recently discovered third group (T. barrioi and T. ceiorum) live in forest brooks; the shadow of the environment allows them to be less aquatic and they indeed have less webbing. The best biometrical differences between these populations have been discovered and illustrated with scatter diagrams. A wide sexual dimorphism has been disclosed in the amount of webbing and the broadez variability of this character in the males suggests cyclical buy dyschronical variation.