The common mudpuppy (Necturus maculosus) is a large, aquatic salamander with a flat, square head, small eyes and a pair of distinctive, feathery gills on either side of its head (2) (3) (4). The gills are generally red, although they vary in tone and in size, with individuals in well-oxygenated habitats usually possessing smaller, inconspicuous gills, whereas those in poorly aerated water have larger, branching, conspicuous gills which are darker in colour (4).
The smooth skin of the adult common mudpuppy can differ in colouration between red, black and grey-brown (2) (3) (4) (5), with variable scattered blue-black spots across its back (3) (5) (6), or occasionally faint stripes (4) (5). The underside of the body is greyish and may also have dark spots (2) (4) (6). Two dark lines run from the snout to the gills (3) (4) (5). The distinctive patterning and colouration fades as the common mudpuppy ages, with older individuals sometimes appearing completely black (4). The tail is short and flattened and the legs are short and slender, but well,-developed, with four toes on each foot (3) (4).
The male and female only differ slightly in appearance, with the male possessing two bumps on the cloaca. The cloacal area of the male becomes significantly swollen during the mating season and has a wrinkled margin (3) (6).
Juvenile common mudpuppies have a highly distinctive pattern, with broad, dark stripes with yellow edges along the back, as well as dark sides and less conspicuous gills than the adult (2) (3) (4) (5).
The common name of the common mudpuppy is thought to either derive from the external gills, which are reminiscent of canine ears (4), or from the erroneous belief that this species makes vocalisations similar to those of a dog (7).
- Adult length: 20 - 30 cm (2)