Although technically salamanders, and therefore amphibians, mudpuppies are completely aquatic and never lose their external gills. Paedomorphism is where juvenile traits are retained by adults, something that is generally an anomaly in a species, but is the normal state for mudpuppies. All salamanders begin life as fully aquatic and then, when their larval stage matures into their adult form they migrate to land - all except for mudpuppies and their immediate relatives.
Scientific & Common Names
Kingdom - Animalia
Phylum - Chordata
Class - Amphibia
Order - Caudata
Family - Proteidae
Genus – Necturus
Species – N. maculosus
Common Names – Mudpuppy, Water Dog, Common Mudpuppy
Mudpuppies are brown or dark grey to almost black with dark spots and red or maroon gills. With short, flat tail and a flat head, they are between 8-12 inches long. They are fully aquatic and live in freshwater streams, ponds, lakes, and rivers. They have a lateral line that measures pressure and motion as well as containing electroreceptor cells. This allows the mudpuppies to detect danger and evade it by quickly swimming to a safer location. For quick getaways, they will fold their legs against their bodies and thrash their flattened tails, allowing them to swim nearly as well as a fish. Unlike other amphibians, mudpuppies retain their exterior gills throughout their lives and never leave the water. They do have lungs and are capable of extracting oxygen from the surface of the water when it becomes necessary, as well as 'breathing' through their skin.
Breeding occurs once a year in the fall or winter, depending on the climate. Females, who are mature at 5-6 years, store the spermatophores until they are ready to fertilize their eggs. They then lay from a few dozen to a few hundred eggs and she will stay with them until they hatch, a trait not usual with salamanders. She will lay them in a protected space under a submerged log or rock. In forty days, the tiny hatchlings emerge but they remain at the nest site for a few weeks and receive nutrition from the remaining yolk from their egg. After the yolk is exhausted, the juveniles will leave the nest.
Mudpuppies will eat nearly anything they can fit into their mouths, including insects, fish, and crustaceans such as crayfish. Natural predators include fish, water snakes, birds, otters, and other salamanders including larger mudpuppies and hellbenders. While they have teeth, they cannot defend themselves well and rely on camouflage and shelter for safety.
Mudpuppies belong to the family Proteidae, which has only six surviving species, five of which are found in North America and an Eastern European cave dwelling species. They diverged from other salamanders early in the Jurassic period, 190 million years ago.
Although they have no negative impact on game fish populations, they are often killed in a mistaken attempt to protect those stocks. They are also, like all amphibians, extremely susceptible to pollutants. Mudpuppies are listed as Least Concern by the International Union for Conservation of Nature and Natural Resources (IUCN), but there are certain protections in areas of their territory. In Maryland they are considered endangered at best but are most likely extirpated (locally extinct).In Iowa they are considered threatened and they are a Species of Special Concern in both North Carolina and Indiana.
- Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo
- International Union for Conservation of Nature and Natural Resources (IUCN)
- North American Amphibians: Distribution and Diversity by David M. Green and Linda A. Weir
- A Guide to Amphibians and Reptiles (Stokes Nature Guides) by Thomas F. Tyning
- Discovering Amphibians: Frogs and Salamanders of the Northeast by John Himmelman