Common mudpuppy (Necturus maculosus)

GenusNecturus (1)
SizeAdult length: 20 - 30 cm (2)

The common mudpuppy is classified as Least Concern (LC) on the IUCN Red List (1).

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).

The range of the common mudpuppy extends south from eastern Canada to northern Georgia in the USA, and includes Wisconsin, Manitoba, Quebec, Alabama, Oklahoma, Louisiana and Mississippi (1) (2) (8). Throughout its range, the common mudpuppy is absent from coastal areas (1) (5).

An entirely aquatic species, the common mudpuppy inhabits freshwater ponds, lakes, streams, canals, reservoirs and rivers (1) (4) (5) (9). It lives close to the bottom of the water body where there are rocks and logs for shelter (1) (4) (9). Adults are mostly found in well-aerated water, in downstream areas or around riffles (9).

Mating in the common mudpuppy occurs between autumn and winter, but the female stores the sperm until April to June, when the eggs are fertilised internally and deposited (3) (4) (7) (9). The female lays between 40 and 150 eggs (2), which are deposited onto the underside of rocks or logs in shallow, slow-flowing water (2) (3) (4) (7) (8). The yellow, spherical eggs are usually between 5 and 6.5 millimetres in diameter and have 3 jelly-like outer layers (2) (9).

The female guards the eggs until they hatch (2) (3) (4), which usually occurs between five and nine weeks after spawning (4) (7) (9), depending on the water temperature (8) (9). By the end of August, most of the young have dispersed from the natal territory, finding new shelter within the surrounding habitat (9). The common mudpuppy becomes sexually mature after four to six years of life (4).

An opportunistic feeder (4), the common mudpuppy has a highly varied diet that is mainly composed of aquatic arthropods, annelids and molluscs, as well as small fish and their eggs, insect larvae and other salamanders (3) (4) (7) (8) (9). The common mudpuppy relies mostly on its sense of smell to detect prey (4).

The common mudpuppy is active all year, although it is most active from late autumn to spring. It is primarily nocturnal, but may sometimes emerge during the day in habitats where the water is cloudy (4).

Predators of the common mudpuppy include the North American otter (Lontra canadensis), water snakes, aquatic birds such as herons, large fish, and occasionally larger mudpuppies (3) (4) (9).

The population of the common mudpuppy is currently thought to be stable and widespread. However, water pollution and siltation are major threats to the habitat of the common mudpuppy, and have already resulted in the decline of certain populations (4) (8). The common mudpuppy is also frequently caught by fishermen and discarded onto land due to the false belief that it is poisonous or detrimental to the game fish population (3) (4) (8) (9).

In Maryland, Iowa, Indiana and North Carolina, the common mudpuppy is considered locally threatened (9).

There are not known to be any specific conservation measures currently in place for this species. However, reducing pollution and siltation from agricultural, industrial and residential areas would improve the quality of the common mudpuppy’s aquatic habitat and help to prevent future population declines (9). 

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  1. IUCN Red List (March, 2012)
  2. Dodd, C.K. (2004) The Amphibians of Great Smoky Mountains National Park. University of Tennessee Press, Knoxville.
  3. Gibbs, J.P., Breisch, A.R., Ducey, P.K., Johnson, G., Behler, J.L. and Bothner, R.C. (2007) Amphibians and Reptiles of New York State: Identification, Natural History and Conservation. University of Oxford Press, Oxford.
  4. Jensen, J.B., Camp, C.D. and Gibbons, V. (Eds.) (2008) Amphibians and Reptiles of Georgia. University of Georgia Press, Georgia.
  5. Raffaëlli, J. (2007) Necturus maculosus. In: Les Urodèles du Monde. Penclen Édition, France. Available at:
  6. Institute of Laboratory Animal Resources (1974) Amphibians:Guidelines for the Breeding, Care, and Management of Laboratory Animals. National Academy of Sciences, Washington, D.C.
  7. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
  8. AmphibiaWeb - Common mudpuppy (March, 2012)
  9. Lannoo, M. (Ed.) (2005) Amphibian Declines: The Conservation Status of United States Species. University of California Press, California.