Completely aquatic and gilled throughout life. The mudpuppy is the largest member of the genus Necturus which also includes waterdogs. All mudpuppies and waterdogshave bushy external gills, two gill slits, a laterally compressed tail, and four toes on front and hind feet. Adult mudpuppies are 20-49 cm total length. Dorsal coloration varies from rusty brown togray or black with bluish black spots or blotches. A dark stripe occurs on the side of the head, passing through the eye and sometimes extending down the side. The venter is white, gray, yellow, orbrown, sometimes with dark spots. Sexually mature males can be distinguished by the swollen cloaca and pair of enlarged cloacal papillae that project posteriorly (Pfingsten and White 1989; Petranka 1998). Hatchlings are 14-15 mm snout to vent length (21-25 mm total length). Juvenile coloration is quite striking, consisting of a dark middorsal stripe bounded by two lightyellow stripes. A dark band occurs below the yellow stripes. Juvenile color pattern becomes more simlilar to adults with age, beginning at 13-15 cm total length (Shoop 1965; Petranka 1998).

Two subspecies are currently recognized which differ in geographic distribution (see below) and coloration. The mudpuppy (N. m. maculosus, sometimes called the common mudpuppy) isrusty brown to grey dorsally, with a gray venter that ranges from unspotted to densely spotted. The Red River mudpuppy (N. m. louisianensis, sometimes called the Louisiana mudpuppy orwaterdog) is light yellowish brown to tan dorsally, sometimes with a dark dorsal stripe bordered by lighter stripes. The back and sides of the belly have large dark spots or blotches, but the midlineof the venter is light colored with no spots (Conant and Collins 1991; Petranka 1998).

A genetic survey found little divergence between populations of mudpuppies from Massachusetts, Minnesota, and North Carolina (Ashton et al. 1980). Necturus beyeri, N.alabamensis, and N. maculosus are relatively closely related (Guttman et al. 1990).

Widely ranging through the eastern United States and into southern portions of Canada. From southeastern Manitoba and southern Quebec to northern Georgia, Alabama,Mississippi, and Louisiana. Primarily west of the Appalachians, extending as far west as eastern Oklahoma, eastern North Dakota, and adjacent areas of Manitoba. The Red River mudpuppy isfound in the Arkansas River drainage and adjacent drainages, from southeastern Kansas and southern Missouri to north-central Louisiana. The rest of the range is occupied by the commonmudpuppy (Conant and Collins 1991; Petranka 1998). Mudpuppies inhabit a variety of permanent aquatic habitats including muddy canals and vegetated bays, large streams withfast-flowing water, sluggish streams, resevoirs, and clear, cool lakes. Animals are found under large rocks, logs, and other cover objects during the day, and they may live as deep as 27 m insome lakes (Petranka 1998).

Mudpuppies are found from southeast Manitoba to southern Quebec, south to south Missouri and northern Georgia.

Biogeographic Regions: nearctic (Native )

Mudpuppies are found from southeast Manitoba to southern Quebec, south to south Missouri and northern Georgia.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)) Southern Manitoba to southern Quebec, south to Oklahoma, northern Louisiana, northern Mississippi, northern Alamaba, and northern Georgia (Conant and Collins 1991). Absent from Coastal Plain. Introduced in New England rivers. See Cochran (1991) for information on distribution in the north-central U.S. in relation to postglacial events.

Mudpuppies are between 20 and 33 cm in length. They are entirely aquatic and have large, maroon colored gills throughout their life. They are gray or rusty brown, to nearly black, marked with black or blue-black spotting or blotching. The pattern ranges from a few random spots to thick stripes. The belly is whitish to grayish, and sometimes has bluish black spots. The head of all mudpuppies is flat, and the tail is short and flattened for swimming. Four toes are found on each of four limbs.  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

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

Length: 43 cm

Mudpuppies live in rivers, weedy ponds, some large lakes, and in lower parts of streams that do not dry up in the summer. 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

• Freshwater

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

Comments: Permanent lakes, ponds, impoundments, streams, and rivers of all sorts. Bottom dweller. Often under rock, debris, bank overhang, etc., during daylight. May move into slack water shallows in late fall and early winter. Eggs are attached to undersides of objects in water. May move upstream to spawn (Green and Pauley 1987).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Upstream movements associated with spawning observed in late winter or early spring in West Virginia (Green and Pauley 1987).

Mudpuppies eat a variety of aquatic organisms. They are opportunistic feeders and will eat whatever they can catch. Cambaridae are a major part of their diet. They also eat Insecta, small fish, fish eggs, aquatic worms, Gastropoda, and other Amphibia 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

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)

Comments: Feeds opportunistically on small aquatic animals.

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.

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:

• water snakes (Nerodia)
• large, predatory fish (Actinopterygii)
• herons (Ardeidae)

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.

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:

• water snakes (Nerodia)
• large, predatory fish (Actinopterygii)
• herons (Ardeidae)

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 - 300

Comments: Represented by many and/or large occurrences throughout most of the range.

10,000 - 1,000,000 individuals

Comments: Total adult population size is unknown but surely exceeds 10,000. Still abundant in many northern lakes and rivers (Petranka 1998).

Mudpuppies have sense organs in their skin that help them detect water movement and pressure changes. These sense organs help them avoid predators. They have small eyes that they use to see with and a good sense of smell, which they use to locate some prey.

Perception Channels: visual ; tactile ; vibrations ; chemical

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

Comments: Nocturnal in clear water, also diurnal in muddy water and in winter.

Mudpuppy eggs take 1 to 2 months to develop, depending on the water temperature. Mudpuppies, like other Proteidae, stay in their larval form for their entire lives.

Development - Life Cycle: neotenic/paedomorphic; metamorphosis

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 been known to live upwards of 20 years.

Average lifespan

Status: captivity: 20 years.

Mudpuppies have been known to live upwards of 20 years.

Average lifespan

Status: captivity: 20 years.

Mudpuppy males join females in sheltered areas under rocks or logs in shallow water during the fall. Males swim and crawl around the females and eventually deposit a small plug of sperm on the substrate. Females pick up the sperm plug and store it inside themselves until it is used to fertilize their eggs in the spring.

Mating System: monogamous ; polygynous

Courtship and mating are in the fall, but some southern populations breed in winter. In spring, females excavate underwater nests and hang 18 to 180 eggs from the nest ceiling. Nests are made in areas with rocks, logs, or other debris for shelter and in water that is 10 cm to 3 m deep. Once hatched, larvae are 20 to 25 mm in length. It takes 4 to 6 years for a mudpuppy to reach sexual maturity.

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)

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)

Lays clutch of about 20-200 eggs in spring or early summer. Eggs hatch in 5-9 weeks. Female may attend eggs until hatching. Attains sexual maturity in 4-6 years. Paedomorphic.

Mudpuppies are locally common throughout their range, although populations are in decline in some areas. They can be found in a variety of aquatic habitats. Habitat destruction from polluted water and loss of ponds and lakes through 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 threaten populations of game fish. Mudpuppies are listed as endangered in Iowa and special concern in Maryland and North Carolina.

IUCN Red List of Threatened Species: least concern

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

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

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread in eastern North America; still abundant in many areas.

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.

Mating usually occurs in autumn or winter, but can extend through April. Precise timing varies with location. Courtship has not been described in detail. Oviposition takes placein May or June (Shoop 1965; Petranka 1998). Nests are excavated by females under rocks, logs, boards, and other submerged cover, and eggs are attached single to the undersides ofthese objects. Reported clutch size range from 30 to 140. Hatching occurs 1-2 months after laying, depending on water temperature. Females apparently attend the eggs during development,protecting them from predation (Shoop 1965; Pfingsten and White 1989; Petranka 1998).

Animals foraging on the bottom at night and retreat to burrows and cover during the day. Mudpuppies are active during winter months. Diet includes a range of aquatic invertebrates andvertebrates, including crayfish, annelids, snails, amphibians, fish, beetle and chironomid larvae, mayflies and caddisflies. Predators are poorly documented, but include water snakes (Nerodia).Humans are another source of mortality as fishers frequently discard mudpuppies on land when they are hooked (Pfingsten and White 1989; Petranka 1998)

Global Short Term Trend: Relatively stable (=10% change)

Although many populations seem to be doing well, pollution and siltation are problems for these animals. Populations in Ohio are apparently declining due to these factors (Pfingsten and White 1989; Petranka 1998).

Comments: Despite widespread pollution and siltation of streams in eastern North America, this species appears to be in minimal need of protection (Petranka 1998).

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 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 and waterdogs are often seen in the pet trade.

Comments: Genetically most closely related to N. beyeri and N. alabamensis (Guttman et al. 1990). Some authors have included in this species certain populations in the Black Warrior River drainage; those populations apparently comprise two species, N. alabamensis and an undescribed species (e.g., see Guttman et al. 1990). Subspecies louisianensis was proposed as a distinct species by Collins (1991, 1997), but supporting data are lacking. Petranka (1998) and Crother et al. (2000) treated louisianensis as a subspecies. See Maxson et al. (1988) for information on Necturus phylogeny based on albumin analysis.