Facultative paedomorphosis in the Alpine newt, Triturus a. alpestris: feeding habits and habitat use in an Alpine lake

摘要

Feeding habits and micro-habitat use were compared between metamorphs and paedomorphs in a population of the Alpine newt, Triturus a. alpestris in the French Alps. This population occupies a deep Alpine lake. The paedomorphs largely outnumbered the metamorphs. Whereas paedomorph diet was mainly composed of plankton, that of metamorphs was especially composed of larval and adult insects. The spatial use of the habitat also differed between the two forms: the paedomorphs occupied all the micro-habitats (shore, bottom, water column and surface) while the metamorphs were only found along the shore and at the water surface. In such a deep lake paedomorphosis may have persisted because of a different use of both feeding resources and micro-habitat