Necturus maculosus maculosus
Common Mudpuppy / Necture tacheté
The Common 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 Common
Mudpuppy can grow to over 40 cm in length.
Adult Common Mudpuppies cannot be confused with any other salamander. Juvenile Common
Mudpuppies can be confused with the larvae of other semi-aquatic salamanders such as the
Northern Two-lined Salamander.
Common 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 Common Mudpuppy.
They have been found in muddy, weed-choked streams as well as 30 m below the surface of
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.
Common Mudpuppies are primarily nocturnal. During the day they are often found under rocks.
They 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 Common 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 Common Mudpuppies examined had limb deformities:
missing toes, extra toes, or other deformities. Otherwise, they are not considered to
be at risk.