Since they lack lungs, all plethodontids breathe through their skin and the mucous membrane in the mouth and throat; these surfaces must remain moist at all times in order to absorb oxygen. All lungless salamanders possess a pair of nasolabial grooves, and each groove extends from the upper lip to a nostril.

Do lungless salamanders have gills?

Other land-living salamanders do not have lungs or gills. These are called lungless salamanders. Instead, they "breathe," or exchange gases, through their skin.

Do Plethodontidae have gills?

Amphiumidae contains three species of Amphiuma, which superficially resemble sirens. Amphiuma, however, lack external gills and can reach an adult length of over 1 m.