''Necturus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of aquatic

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

s native to the eastern United States and Canada. They are commonly known as waterdogs and mudpuppies. The

common mudpuppy The common mudpuppy (''Necturus maculosus'') is a species of salamander in the genus ''Necturus''. They live an entirely aquatic lifestyle in parts of North America in lakes, rivers, and ponds. They go through paedomorphosis and retain their ext ...

''(N. maculosus)'' is probably the best-known

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

– as an amphibian with gill slits, it is often dissected in comparative anatomy classes.

Taxonomy

The genus is under scrutiny by

herpetologists Herpetology (from Greek ἑρπετόν ''herpetón'', meaning " reptile" or "creeping animal") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians (gymnophiona)) an ...

. The relationship between the species is still being studied. In 1991 Collins elevated ''N. maculosus louisianensis'' to full species status, usually considered a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

of the common mudpuppy (''N. maculosus''), but his interpretation was not largely followed.Petranka, J.W. (1998). Salamanders of the United States and Canada. Smithsonian Institution Press . However, a 2018 study confirmed it as a distinct species, with

Amphibian Species of the World ''Amphibian Species of the World 6.1: An Online Reference'' (ASW) is a herpetology database. It lists the names of frogs, salamanders and other amphibians, which scientists first described each species and what year, and the animal's known range. ...

following these results, although other authorities do not.''''

Species

There are seven to eight species: Two known fossil species, '' N. krausei'' and an unnamed species, are respectively known from the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pala ...

Saskatchewan Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...

and from Florida during the Pleistocene.

Description

''Necturus'' are

paedomorphic Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compare ...

: adults retain larval-like morphology with external gills, two pairs of gill slits, and no eyelids. They are moderately robust and have two pairs of short but well-developed limbs and a large, laterally compressed tail. Lungs are present but small. Typical adult size is in total length, but ''Necturus punctatus'' is larger and may reach .

Ecology

''Necturus'' occur in surface waters, preferentially with clear water and rocky substrates without silt. They forage during the night and eat a variety of prey, but have preference for

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, m ...

References

External links

* {{Taxonbar, from=Q641652 Proteidae Amphibian genera Extant Paleocene first appearances Taxa named by Constantine Samuel Rafinesque