Mole Salamander - General Description

General Description

Terrestrial mole salamanders are identified by having wide, protruding eyes, prominent costal grooves, thick arms, and rounded tails. Most have vivid patterning on dark backgrounds, with marks ranging from deep blue spots to large yellow bars depending on the species. Terrestrial adults spend most of their life underground in burrows either of their own making or abandoned by other animals. Some Northern species may hibernate in these burrows throughout the winter. They live alone and feed on any available invertebrate. Adults spend little time in the water, only returning to the ponds of their birth to breed.

All mole salamanders are oviparous and lay large eggs in clumps in the water. Their fully aquatic larvae are branchiate, with 3 pairs of external gills behind their head and above their gill slits. Larvae have large caudal fins which extend from the back of their head to their tail and to their cloaca. Larvae grow limbs soon after hatching, with four toes on the forearms, and five toes on the hindlegs. Their eyes are wide-set and lack true eyelids.

The larvae of some species (especially those in the South, and Tiger salamanders) can reach their adult size before undergoing metamorphosis. During metamorphosis, the gills of the larvae disappear, as does the fin. The tail, skin, and limbs become thicker, and the eyes develop lids. Their lungs become fully developed, allowing for a fully terrestrial existence.