About Necturus maculosus (Rafinesque, 1818)
The common mudpuppy, with the scientific name Necturus maculosus (Rafinesque, 1818), is a species of salamander in the family Proteidae. It lives a fully aquatic life in lakes, rivers, and ponds across parts of North America. This species undergoes paedomorphosis and retains its external gills throughout life. Since gas exchange through skin and lung respiration alone is not enough, common mudpuppies rely on their external gills as their primary method of gas exchange. Their bodies are usually rusty brown, and they reach an average total length (including the tail) of 13 inches (330 mm). Common mudpuppies are nocturnal, and are only active during the day if the water they inhabit is murky. They are generalist feeders, and their diet includes almost any prey they can capture, such as insects, mollusks, earthworms, and other annelids. After a female common mudpuppy reaches sexual maturity at six years of age, she lays an average of 60 eggs. In the wild, the average lifespan of a common mudpuppy is 11 years. The native range of Necturus maculosus covers streams, lakes, and ponds in eastern North America. Their native distribution extends from southern Canada as far south as Georgia, and from the Midwestern United States east to North Carolina. There is also an introduced established population in Maine. Behaviorally, common mudpuppies hide under cover like rocks and logs during the day, and become more active at night. In murky, muddy waters, they may be active during the day, and they can even survive under the ice when lakes freeze over. Common mudpuppies require six years to reach sexual maturity. Mating usually occurs in autumn, but females do not lay eggs until much later. When males are ready to breed, their cloacae swell. Males deposit spermatophores on the environment’s substrate. Females pick up these spermatophores with their cloaca, and store the sperm in a small specialized gland called a spermatheca, until ovulation and internal fertilization occur. Fertilization typically happens just before females lay eggs in the spring. Before egg deposition, male mudpuppies leave the nesting area. When ready, females deposit their eggs in a protected location, most commonly on the underside of a rock or log. Clutch sizes range from 20 to 200 eggs, with an average of 60 eggs per clutch. The eggs are unpigmented, and measure around 5–6 mm (0.20–0.24 in) in diameter. The female remains with her eggs throughout the incubation period, which lasts around 40 days. When they hatch, hatchlings are about 2.5 cm (0.98 in) long, and grow to 3.6 cm (1.4 in) before their yolk sac is fully consumed.
