Temperature-mediated characteristics of the dusky salamander (Desmognathus fuscus) of Southern Appalachia.

Abstract

Desmognathus fuscus is a nocturnal plethodontid salamander of moist forest floor and stream banks of Appalachia and the Eastern United States. This study addresses the question of temperature selection and its accompanying variables in a terrestrial species. Using a thermal gradient in the laboratory, I found no preferred temperature for fasting or postprandial D. fuscus. I compared the rate at which D. fuscus cooled and heated with that of a similarly sized tube of physiological saline and found no significant difference, which indicates that D. fuscus exhibits no physiological control of its heating and cooling rates. I determined the desiccation rate at 16°C and 26 °C and found a significantly higher rate of desiccation at 26°C, which indicates that the only likely control over desiccation is behavioral. All of these findings fit very well with what is known of the life history of D. fuscus and with how this species fits into the range of life history traits found throughout this genus.