Body size, age and population structure of Triturus carnifex (Urodela: Salamandridae) in the context of facultative paedomorphosis

Abstract

Facultative paedomorphosis occurs rarely in the genus Triturus compared to other European newts such as Ichthyosaura alpestris and Lissotriton spp., with most of observation related to single or few individuals per site. In this paper we report about body size, age and population size of two populations of Triturus carnifex with paedomorphs. Since one of the populations consisted of approximately 25% of paedomorphs, this is the first study about a population of large-bodied newts with a conspicuous number of paedomorphic individuals. We found evidences for an ecological causation of paedomorphosis, as well as further support for two recent findings about paedomorphosis: the reduction of sexual size dimorphism and the female-biased sex-ratio within paedomorphs.