Necturus maculosus (Rafinesque, 1818)


Key Characters: Bushy external gills; 4 toes on hind feet; dark stripe running through eye.

Similar Species: Hellbender, larval Ambystoma. See Key to Adult and Larval Salamanders of Illinois for help with identification.

Subspecies: Mudpuppy, N. m. maculosus, Common Mudpuppy and N. m. louisianensis, Viosca, 1938, Red River Mudpuppy.  Only the Common Mudpuppy is found in Illinois.

Description: Large (up to 34 cm TL), stout-bodied brownish gray, rust brown, or black salamander with scattered round black spots of various sizes. Costal grooves 15-16. Belly gray with dark spots, or plain gray. Snout blunt, head flattened and widest behind eyes. Tail short, tail fins not extending onto body. Larva and juvenile have broad dark stripes down back that are bordered on either side by yellow stripes.

Habitat: Lakes, ponds, rivers, and large creeks. More abundant in clear waters but can withstand turbid, mud-banked streams if gravel headwaters are available for reproduction.

Natural History: This totally harmless and attractive salamander is active year-round. Shelters by day in deeper water under rocks, piles of driftwood, overhangs, and other objects. Feeds at night on fish, crayfish, aquatic insects, and other invertebrates. Males search out females in autumn and mate in depressions under large rocks, logs, boards, or other submerged objects. Female attaches eggs to underside of rocks or logs the following spring. Larvae hatch in 1-2 months and mature in 5-6 years.

Distribution Notes: Historically statewide but now restricted to a few clear rivers and streams and Lake Michigan.

Status: Seldom seen, except by fishermen, making surveys difficult. Threatened in Illinois.

Etymology: Necturus – nektos (Latin) for swimming; oura (Greek) for tail; maculosus – (Latin) for dappled, spotted.

Original Description: Rafinesque, C.S. 1818. Further account of discoveries in natural history in the western states.  American Monthly Magazine and Critical Review. 4(1):39-42.

Type Specimen: Not designated.

Type Locality: “found in the Ohio” = Ohio River

Original Name: Sirena maculosa Rafinesque, 1818

Nomenclatural History: Transferred to the genus Necturus by Rafinesque (1819, J. Phys. Chim. Hist. Nat. Arts, 88: 417).  Other junior synonyms exist; the only one used in the Illinois literature is: Triton lateralis Say In James, 1822 (Account Exped. Pittsburgh-Rocky Mts., 1: 5) and the combinations Menobranchus lateralis, and Necturus lateralis.