Three-lined salamanders are found in swampy areas, along the margins of sluggish streams, often in similar habitats as Desmognathus auriculatus . Adults are predominantly terrestrial and may be found just about any time of the year, even if parts of the stream have dried. The dwarf salamander is aptly named, as it is one of the smallest vertebrates in North America. Full-grown adults frequently weigh less than one gram and may be less than 2 inches long from snout to tail tip. One species is bronze-brown colored while the other is yellow.
Larval development is completed in the bays in five to six months.
Males mature at less than one year of age, but females take twice as long to reach first reproduction. All slimy salamanders are morphologically similar, being a deep dark blue to black, usually with whitish spots. The size and number of spots vary both within and among species in the complex. On the SRS, the animals are usually black with medium-sized white spots along the sides and with smaller and more widely spaced flecks on the back. The skin secretions, a defensive mechanism, may become stuck to the skin of collectors, not to mention the mouths of would-be predators, and require strenuous scrubbing to remove.