Description

The Mudpuppy is Canada's only completely aquatic salamander. It is gray to rusty-brown on top with dark blue spots with a gray belly. It has feathery dark red external gills and has only four toes on both the front and hind feet. Juvenile Mudpuppies are black with longitudinal yellow stripes. Counting the tail, the mudpuppy can grow to over 40 cm in length.

Confusing Species

Adult Mudpuppies cannot be confused with any other salamander. Juvenile Mudpuppies can be confused with the larvae of other semi-aquatic salamanders such as the Northern Two-lined Salamander.

Distribution

Mudpuppies are largely restricted to the Great Lakes-St Lawrence Basin although they are also found in southern Manitoba. In Canada they are limited to south-eastern Manitoba, southern Ontario and southern Quebec. Outside of Canada, they are found as far south as Louisiana.

Habitat

Lakes, rivers and streams of almost all kinds are the habitat of the Mudpuppy. They have been found in muddy, weed-choked streams as well as 30 m below the surface of Lake Michigan.

Reproduction

Breeding occurs in the spring. Females lay 30-190 eggs, one at a time, on the underside of rocks along stream bottom. The larvae hatch within two months at approximately 2 cm total length. It can take four to six years for the larvae to reach maturity.

Natural history

Mudpuppies are primarily nocturnal. During the day they are often found under rocks. Mudpuppies are carnivourous feeding on worms, insects and small fish. Individuals that make it to adulthood have few natural enemies and can live for over 30 years.

Conservation Concerns

Research on Mudpuppies in the St Lawrence River has found high levels of PCBs and organochlorine pesticides in their eggs. At one site along the St Lawrence with the highest levels of PCBs, over 60% of the Mudpuppies examined had limb deformities: missing toes, extra toes, or other deformities.