Facultative paedomorphosis and developmental stability in European newts (Triturus spp, Salamandridae): Ontogenetic aspect

Abstract

Cranial asymmetry was analyzed at different ontogenetic stages of two paedomorphic newt species (Triturus vulgaris and T alpestris). Attention was focused on fluctuating asymmetry (FA), a measure of developmental stability. The analysis of cranial asymmetry in facultatively paedomorphic populations showed that during ontogeny the FA remains similar or even increases, regardless of the ontogenetic pathway. Paedomorphs and metamorphosed adult individuals did not show any considerable differences in FA. The observed variations in FA among analyzed cranial traits, indicate that developmental precision appear to be more trait specific, dependent on stage and degree of development, and variable during ontogeny.