Lungless Salamanders: Plethodontidae

Physical characteristics: Dusky salamanders are about 5.5 inches (14 centimeters) long from tip of snout to tip of tail. They have short legs and a stocky build. The hind legs are much larger than the front legs. The head is wedge shaped and has large eyes that bulge out. The jaw and neck muscles are thick. The tail has a low fin and ends in a sharp point. The tail grows back if it is pulled off by a predator, but it grows back with a blunt end rather than a sharp tip. Dusky salamanders usually are darker on the back than on the belly, which is cream colored. The back is mottled gray and black, striped with various shades of tan to yellowish brown to brown. A black stripe extends from the eye diagonally back to the angle of the jaw.

Dusky salamanders lay the eggs in clusters of five to thirty in moist, hidden places in seepage pools on rocks or at the edges of springs and small streams. The female guards the eggs until they hatch in about forty-five days. (© E. R. Degginger/Photo Researchers, Inc.)

Geographic range: Dusky salamanders live in Quebec and New Brunswick in eastern Canada. Their range extends south and west as far as Indiana and South Carolina in the United States.

Habitat: Dusky salamander larvae live in springs, in small streams, and in water that has seeped up through the ground and collected in a pool. Adults spend some time on land but spend most of their time in seeped-up water or on the sides of springs and small streams, where they live among rocks or under logs.

Diet: Dusky salamander larvae mainly eat small invertebrates (in-VER-teh-brehts), or animals without backbones, such as the larvae of water-dwelling insects. They also eat tiny crustaceans and clams. Adults eat land-dwelling prey, mainly small insects and crustaceans, but they feed on water-dwelling insects when in the water. Larger dusky salamanders eat larger prey, but they continue to eat small prey. These salamanders sometimes eat one another, especially the larvae of others in their species. Adults capture their prey by rapidly flicking their tongues and snapping their jaws.

Behavior and reproduction: Dusky salamanders are active animals. They move very fast and are hard to catch. Most of their normal activity takes place in the early evening, but when conditions are warm and moist, these salamanders may be active throughout the night. By day dusky salamanders typically stay under cover. Dusky salamanders defend themselves from predators by remaining motionless or by biting.

Dusky salamanders mate on land. The male lures the female by rubbing her head with his body, waving his front legs, and placing himself alongside her and snapping backward. He approaches the female and positions her head at the base of his tail. He then walks forward, moving his tail back and forth while the female follows. The male releases a sperm bag, and the female takes it into her body. The female stores the sperm inside her. The eggs are fertilized when the female is ready to lay them in middle to late summer. She lays the eggs in clusters of five to thirty in moist, hidden places in seepage pools on rocks or at the edges of springs and small streams. The female guards the eggs until they hatch in about forty-five days. When the larvae hatch, they still have plenty of nutrients from the egg and do not feed immediately. Larvae grow slowly in the fall and winter but rapidly in the spring and go through metamorphosis in about nine months.

Dusky salamanders and people: Dusky salamanders have no known importance to people.

Conservation status: Dusky salamanders are not considered threatened or endangered. They are one of the most common salamanders in eastern North America. These salamanders adapt well to changes in their habitat as long as there are enough small streams. ∎