Mudpuppy

Geographical Origin and Habitat: A massive, neotenic aquatic salamander native to the glacial lakes, deep rivers, and highly oxygenated gravel streams of eastern North America and Canada. Commonly known as the Common Mudpuppy or Waterdog, it inhabits cold, dark depths, avoiding light and seeking refuge under logs and rocks.

Taxonomy and Genetics: Belonging to the family Proteidae. As a strictly neotenic species, it retains larval characteristics throughout its entire life, including large, feathery red external gills, four short legs, and a laterally compressed paddle-like tail. The skin is extremely smooth and slimy, with a brown, gray, or olive base color heavily mottled with dark spots.

Behavior and Habits: Primarily nocturnal, spending the day hidden under rocks or submerged logs on the riverbed. At night, it becomes an active hunter, walking slowly along the bottom and using vacuum suction to capture prey. It remains active under the ice during cold winter months.

Morphology: Females are generally larger, heavier, and broader than males, especially when carrying eggs. Males are more slender and exhibit a slightly swollen cloaca during the breeding season.

Terrarium Setup: Must be kept in a large, fully aquatic tank (minimum 100-120 cm in length, 200+ liters). Provide a water depth of 30-40 cm. The substrate should consist of fine sand or large, smooth river stones to prevent accidental ingestion and impaction. A tight-fitting lid is mandatory as they can escape. Provide large, dark caves using stones or PVC pipes for shelter.

Lighting and Heating: Adapted to cold, temperate climates. Water temperature must be kept low, between 10 and 18°C. High temperatures are highly dangerous; water exceeding 22°C can cause gill necrosis, respiratory distress, and death, making a water chiller mandatory. Lighting should be very dim, as they are sensitive to bright light.

Humidity and Hydration: Being strictly aquatic, water quality is critical. The water must be clean, well-filtered, and highly oxygenated, with a constant flow. Use dechlorinated water, as chlorine damages their skin and gills. Perform regular water changes of 30-40% weekly, supported by a heavy-duty canister filter to manage waste.

Feeding and Supplementation: A voracious carnivore. Feed on whole items such as nightcrawlers, earthworms, small thawed fish (like silversides), and freshwater shrimp. They strike quickly using suction. Ensure a varied diet to support proper growth and bone density.

Compatibility: Highly territorial and aggressive towards smaller animals, which they will eat. Can be kept with conspecifics of similar size only in very large tanks with multiple separate hides. Otherwise, severe fighting and gill-biting will occur. Best housed individually.

Health and Common Diseases: Extremely sensitive to heat and poor water quality, which lead to ammonia poisoning, bloating, skin ulcers, and saprolegnia fungal infections on the gills. Never handle with bare hands, as human skin acids, soaps, and warmth will damage their sensitive protective slime coat and induce severe stress.