Overview
The Northern Dwarf Siren (Pseudobranchus striatus) is a miniature, eel-like aquatic salamander native to the lush, mossy wetlands of the American Southeast. An evolutionary enigma that possesses only two tiny front legs and completely lacks hind limbs, this permanently aquatic amphibian breathes through bushy external gills and maneuvers like a graceful water snake through dense mats of floating aquatic vegetation.
Biology and Physical Characteristics
Pseudobranchus striatus has a slender, cylindrical, eel-like body colored dark greyish-brown to olive-black, dramatically highlighted by bold yellowish-buff or silvery-white lateral stripes running from its head to its tail. It possesses three pairs of feathery external gills, a tiny mouth with horny beak-like jaws rather than teeth, and tiny three-toed front limbs that it uses to pull itself through tangled aquatic roots.
Behavior and Ecology
A master of survival in ephemeral coastal plain wetlands, the Northern Dwarf Siren spends its life buried within dense submerged root masses of water hyacinth, pickerelweed, and sphagnum moss. When summer droughts cause its wetland home to evaporate completely, it burrows deep into damp organic peat mud and secretes a protective mucus cocoon, remaining dormant for months until rain refits the basin.
Conservation and Human Impact
Classified as Least Concern by the IUCN, the Northern Dwarf Siren is locally abundant throughout healthy coastal plain wetlands in Georgia and Florida. However, it is vulnerable to the ditching and draining of isolated cypress depression wetlands for residential development, pine silviculture, and pesticide runoff.
Interesting Factoid
The Northern Dwarf Siren only has two legs; evolution completely eliminated its hind limbs and pelvic girdle, leaving it with just two tiny front arms and a sleek eel-like body designed for swimming through floating root tangles.