(see family information on Tree of Life site)
4 species in 2 genera


Elongate small to large (750 mm) aquatic salamanders with external gills. The pelvic girdle and hind limbs are absent in all species but small forelimbs are present. They are distributed in the southern United States and northern Mexico and usually are considered to be the sister group to all other living salamanders. Two genera belong to this family, Siren, and Pseudobranchus. Members of this family are paedomorphic, with adults retaining larval features such as gills, a lateral line system, and suction feeding (although they also possess moving jaws). Some morphological characters for this group include: 1) non-pedicellate teeth; 2) maxillae reduced to tiny-free elements; 3) no pelvic girdle; 4) no premaxillary or maxillary teeth.

Siren intermedia intermedia
Photo by John White
(Click for details)

Genus Pseudobranchus (2 species)
Pseudobranchus axanthus AmphibiaWeb account photos no sound/video
Pseudobranchus striatus AmphibiaWeb account photos no sound/video

Genus Siren (2 species)
Siren intermedia AmphibiaWeb account photos no sound/video
Siren lacertina AmphibiaWeb account photos no sound/video

Citation: AmphibiaWeb: Information on amphibian biology and conservation. [web application]. Berkeley, California: AmphibiaWeb. Available: (Accessed:

AmphibiaWeb's policy on data use.