Newts and salamanders have four similarly sized legs as well as a distinct tail. They are the only vertebrates that have the ability to regenerate body parts, such as legs and tails.

The only salamander in the Newport Aquarium collection at this time is the mudpuppy (Necturus maculosus), a salamander that is found in lakes and streams in the eastern regions of North America. Unlike other salamanders, the mudpuppy only has four toes on each hind foot. The mudpuppy has external gills which easily can be seen. Mudpuppies will feed on amphibians, fish, insects, and mollusks.