Age, Sexual Dimorphism, and Growth Rates in the Black Salamander,Aneides flavipunctatus(Plethodontidae)

Abstract

To understand how rates of growth interact to result in sexual dimorphism in the Black salamander, Aneides flavipunctatus, I conducted a mark–recapture study in Mendocino County, California. Five hundred captures (420 unique animals plus 80 recaptures over four occasions) were measured (body length, head width, head length) and released. Adult males and females are not sexually dimorphic in body length, but are dimorphic in head width; males have wider heads compared to females. From 80 recaptures, growth rates were determined for body length and head size. As expected, juveniles grow faster relative to adults; growth rates decrease as body size increases. Adult males and females have similar growth rates of body length. Males and juveniles have greater head-width growth rates compared to adult females. Head size dimorphism in A. flavipunctatus is a result of a higher head growth rate in males at sexual maturity relative to females. Because body growth rates are not significantly different between adult m...