The Common Mudpuppy is a species of aquatic salamander indigenous to North America. They can be found in rivers in the northeastern United States, and parts of Canada. Mudpuppies prefer shallow water with many places to hide, but have been found at depths of up to 90 feet. The common mudpuppy is nocturnal, but can be active in the day in muddy or weed-choked waters. It is carnivorous and feeds on fish, fish eggs, crayfish, insects, and molluscs. Mudpuppies are neotenous; a form pedomorphosis in which certain organs and organ systems mature at a faster rate than others.