Life History Aspects of Paedogenic Populations of the Mole Salamander, Ambystoma talpoideum

Three populations of the mole salamander, Ambystoma talpoideum, were studied in South Carolina. Terrestrial, fossorial adults migrate to water to breed in late fall or early winter and return to land the following spring. The larvae hatch in early spring. Metamorphosis can occur at any time provided the individual has achieved a minimum size estimated at greater than 25 mm snout-vent length. If the young remain in the water through the following fall, they mature sexually. Most metamorphose 12 to 15 months after hatching, but a few remain permanently aquatic. Larval reproduction in other species of Ambystoma has been linked to unfavorable terrestrial environments. As the southeastern U.S. generally offers favorable terrestrial habitat for salamanders, the conditions of the aquatic habitat may be more crucial. If the aquatic habitat is suitable for larvae, they do not metamorphose prior to sexual maturity. If aquatic conditions become unfavorable they may transform before they reach sexual maturity and emerge as immature terrestrial forms.