Dwarf siren

Dwarf sirens are eel-like salamanders of the genus Pseudobranchus. Dwarf sirens possess external gills throughout adulthood and lack hind legs, and can be distinguished from members of the genus Siren in that dwarf sirens have three toes on each foot rather than four. Whereas sirens has three gill slits, dwarf sirens keeps just a single slit. Like sirens, dwarf sirens are restricted to the Southeastern United States.

Species
The genus Pseudobranchus consists of the following extant species:


 * Southern dwarf siren (P. axanthus)
 * Narrow-striped dwarf siren (P. a. axanthus)
 * Everglades dwarf siren (P. a. belli)
 * Northern dwarf siren (P. striatus)
 * Broad-striped dwarf siren (P. s. striatus)
 * Gulf Hammock dwarf siren (P. s. lustricolus)
 * Slender dwarf siren (P. s. spheniscus)

There are also two extinct species known from fossil evidence:


 * †Pseudobranchus vetustus (Miocene to Pliocene of Florida)
 * †Pseudobranchus robustus (Pleistocene of Florida)