Species Fact Profile: Mudpuppy (Necturus maculosus)

Mudpuppy/Waterdog

Necturus maculosus (Rafinesque, 1818)

Range: Southeastern Canada, Eastern United States
Habitat: Lakes, Rivers, Streams
Diet: Small Fish, Aquatic Invertebrates (Worms, Crayfish, Insects), Small Amphibians
Social Grouping: Solitary
Reproduction:  Sexually mature at about 6 years of age (or at about 20 centimeters in length).  males deposit packets of sperm in the fall on the bottom of streams, which are picked up by females in their reproductive organs until they lay their eggs (average of 60, but anywhere from 20-200) in the spring.  Females watch over the eggs for the approximately 40 day incubation period.  hatchlings are 2-3 centimeters long when they emerge
Lifespan: 10-20 Years
Conservation Status: IUCN Least Concern

• Average body length 33 centimeters.  The body is long and cylindrical with small, flattened limbs and a large flat head with tiny eyes.  The tail is laterally compressed
• Coloration is varied, but ranges from dull grey to a rust-like brown color, often with dark colored spots.  In clear water their skin becomes darker; in dark water it becomes lighter
• Mudpuppies do not undergo mull metamorphosis like many other salamanders, and so retain their external gills, appearing as a set of red feather-like growths behind the head.  Mudpuppies living in stagnant, oxygen-poor water have larger external gills
• Good swimmers, folding their limbs against their bodies and paddling with their tails, but most often walk along the bottom of streams
• Mucous glands on the skin secrete a slime which coats the body; they can also secrete a poison which can be used for defense.  Predators include large fish, water snakes, herons, and snapping turtles
• Active by night, spends the day hiding under rocks or sunken logs, though if the water is very muddy and visibility is poor, they may be active by day
• The name "mudpuppy" is typically used in the northern part of the range; in the southern US, they are more often called "water dogs"
• Three subspecies recognized - the common, Lake Winnebago (N. m. stictus), and Red River (N.  m. louisianensis) mudpuppies.  Throughout the American South, it is sometimes replaced by or lives alongside other similar, closely related species, such as the Alabama waterdog and Gulf Coast waterdog
• Overall common (if seldom seen), though sometimes opportunistically persecuted by fishermen who believe (falsely) that they kill game fish.  They are listed as endangered or threatened in some US states, such as Iowa, Maryland, and North Carolina