Mudpuppies have sense organs in their skin that help them detect water movement and pressure changes. These sense organs help them avoid predators. They also have a good sense of smell, which they use to locate some prey. They have small eyes that they use to perceive light. Courtship is the only time when mudpuppies communicate with each other to coordinate mating. They may use a combination of touch and chemical cues in courtship.
Perception Channels: visual ; tactile ; vibrations ; chemical
Mudpuppies are locally common throughout their range, although populations are in decline in some areas. They are tolerant of a variety of aquatic habitats. Habitat destruction from siltation and pollution, and habitat loss due to development is a threat to some populations. Because of their sensitive skin, they are especially vulnerable to toxins in the water. Populations are also threatened by needless persecution, as some anglers kill mudpuppies in the mistaken belief that they impact populations of game fish. Mudpuppies are listed as endangered in Iowa and special concern in Maryland and North Carolina.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Mudpuppy eggs take 1 to 2 months to develop, depending on water temperature. Mudpuppies, like other members of Proteidae, are neotenic, retaining their larval form throughout life.
Development - Life Cycle: neotenic/paedomorphic; metamorphosis
Mudpuppies have no negative impact on humans. Some people believe that they eat the eggs of game fish and kill them, but there is no evidence that mudpuppies impact game fish populations. People are also sometimes frightened by the strange appearance of mudpuppies, but they are completely harmless.
Mudpuppies have little economic importance. They are sometimes collected and used in research and education. They are important members of native aquatic ecosystems.
Positive Impacts: research and education
Mudpuppies are important predators of aquatic invertebrates and small fish in their native aquatic ecosystems. They also are eaten by larger aquatic predators, like large fish, herons, and water snakes.
Mudpuppies eat a variety of aquatic organisms. They are opportunistic feeders and will eat whatever they can catch. Crayfish are a major part of their diet. They also eat insect larvae, small fish, fish eggs, aquatic worms, snails, and other amphibians are also eaten. They will also eat carrion and are often caught in traps that are baited with dead fish.
Animal Foods: amphibians; fish; eggs; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic crustaceans
Primary Diet: carnivore (Eats non-insect arthropods)
Mudpuppies are found from southeast Manitoba to southern Quebec, south to south Missouri and northern Georgia.
Biogeographic Regions: nearctic (Native )
Mudpuppies live in rivers, weedy ponds, some large lakes, and in perennial streams. Mudpuppies need water that has an abundance of shelter. They reside under logs, rocks, or weeds during the day. They are rarely seen, but may be found under rocks in shallow water. Mudpuppies can be found in either shallow or deep water, depending on the season. They have been reported in water as deep as 30 meters.
Range depth: 30 (high) m.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams
Mudpuppies have been known to live upwards of 20 years.
Average lifespan
Status: captivity: 20 years.
Mudpuppies are between 20 and 33 cm in length. They are neotenic (permanent larvae) and retain large, maroon colored external gills throughout their life. Mudpuppies that live in cold water with high oxygen concentrations have shorter gills than those living in oxygen depleted waters. They have a general coloration of gray or rusty brown, to nearly black. They are marked with black or blue-black spotting or blotching. The spotting pattern ranges from a few spots, to many spots, or spots merging to form stripes. The belly is whitish to grayish, and sometimes has bluish black spots. There are two generally recognized subspecies. Necturus m. maculosus individuals have rusty brown to gray dorsa with conspicuous spotting. The underside is gray, and may or may not be spotted. Louisiana waterdogs (N. m. louisianensis) have light yellowish brown to tan dorsa. The dorsal side is marked with large spots and sometimes a dorsal stripe. The belly is light colored with no spots.
The head of all mudpuppies is flat and the tail is short and laterally compressed for swimming. Four toes are present on each of four well-developed limbs. Males and females look very similar. However, male cloacae have two prominent papillae directed backward. In the breeding season, males have swollen cloacae. Female cloacae are slit-like and usually surrounded by light coloration. Young mudpuppies are black with longitudinal yellow stripes.
Range length: 20 to 33 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Large fish, water snakes, and wading birds, such as herons, prey on mudpuppies. Mudpuppies avoid predators by hiding under logs, rocks, or thick vegetation.
Known Predators:
Mudpuppies form mating aggregations in the fall in shallow water. Males join females in sheltered areas under rocks or logs in shallow water. Males swim and crawl around the females and eventually deposit a 1 cm spermatophore. Females pick up the spermatophores in their cloaca, where it is stored until spring.
Mating System: monogamous ; polygynous
Courtship and mating take place in the fall, but some southern populations breed primarily in winter. Fertilization is internal, with the female taking up the male's spermatophore in her cloaca and storing it there until fertilization in the spring. In spring, females excavate nest cavities and suspend from 18 to 180 eggs from the nest cavity ceiling. Nest cavities are constructed in areas with rocks, logs, or other debris for shelter and in water that is 10 cm to 3 m in depth. Eggs are between 5 and 11 mm in diameter. Once hatched, larvae are 20 to 25 mm in length. It takes 4 to 6 years for a mudpuppy to reach sexual maturity, at a body length of about 20 cm.
Breeding interval: Mudpuppies breed once a year.
Breeding season: Courtship and breeding occurs in the fall, or during winter in southern populations. Fertilization and development occur in the spring.
Range number of offspring: 18 to 180.
Range time to hatching: 1 to 2 months.
Range age at sexual or reproductive maturity (female): 4 to 6 years.
Range age at sexual or reproductive maturity (male): 4 to 6 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous ; sperm-storing
Female mudpuppies lay their eggs in nest cavities that they dig in sheltered areas beneath rocks and logs. Nest openings usually face downstream. The eggs are attached to the roof of the nest and the females remains with them until they hatch - between 1 and 2 months.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Female)
