The family Proteidae is a group of aquatic salamanders found today in the Balkan Peninsula and North America.

The range of the genus Necturus (commonly known as waterdogs or mudpuppies) runs from southern central Canada, through the midwestern United States, east to North Carolina and south to Georgia and Mississippi.

The fossil record of the family extends back to the Late Cretaceous, with Paranecturus being known from the Maastrichtian of North America, and Bishara from the Santonian-Campanian of Central Asia.

The bright red exposed gills are often found closed against the body in cool, highly oxygenated water.

Necturus salamanders such as "mudpuppies" also absorb oxygen through their skin and by occasionally breathing air at the surface.