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.
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.
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.
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.
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.
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.
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.