Variability and microevolutionary patterns in Triturus marmoratus from Portugal: age, size, longevity and individual growth

Abstract

We conducted a comparative study of some biological parameters between different allopatric northern (high and low altitudes) and southern (low altitude) populations of Triturus marmoratus in Portugal. Individual age was determined by counting lines of arrested growth in histological sections of the humerus and phalanx. This study documents interpopulational differences in longevity, age of sexual maturity and growth of individuals. Individuals from high altitudes in the north reached older ages than those from low altitudes but both reached older ages than those from the south. Maturity was reached sooner among the southern newts for both sexes when compared to the northern populations. The southern newts also reached their sexual maturity at smaller mean sizes than the northern ones. We interpret these differences and suggest how genetical and epigenetical components can be both involved and account for the observed variability.