Reproductive Biology of the Mud Salamander, Pseudotriton montanus, in Western South Carolina

The reproductive biology of Pseudotriton montanus was studied for two populations in the Piedmont of western South Carolina. Males reached sexual maturity during the first year following metamorphosis, and attained breeding condition in their second, third or fourth summer of life, depending on the duration of the larval phase and on the season of metamorphosis. Males produced sperm annually, with evacuation of the testes beginning in late July and continuing through the autumn. All mature males taken from August through November had vasa deferentia packed with sperm. Females were found to oviposit initially in the autumn or winter at four or five years of age, and thereafter on an irregular schedule. Clutch size increased as a function of body size, and ranged from 77 to 192 eggs/female. In comparison with Pseudotriton ruber, P. montanus shows more rapid growth, earlier maturity and higher fecundity. Such a life-history strategy may be a consequence of r-selection in response to intrinsically hazardous and uncertain environments. It is proposed that the irregular female reproductive cycle of P. montanus is a facultative adaptation which prolongs life and provides for iteroparity under conditions of variable juvenile and constant adult mortality, yet allows for high fecundity, especially in the initial reproductive year, under overall conditions of r-selection.