The two-toed amphiuma (Amphiuma means) not only surprises many visitors with its unusual size and shape, but also often mystifies visitors to even its correct species.

Actually a snake-like salamander, the amphiuma is often thought to be an eel or water snake and is commonly, but incorrectly, called a “congo snake,” “lamper eel” or “conger eel.” Its thick, blue-black (or gray-black) body is about 36 inches long in a mature adult, making it the largest amphibian in North America.

They can go years without food and are known to live for as many as 27 years.

The three species of Amphiuma can be distinguished by the number of toes on their tiny limbs: pholeter has one toe, means has two and tridactylum has three. The two-toed is the most common of the three.

The misnomer of eel is well-deserved considering its long, slender bodies and inconspicuous legs.

However, it’s a true amphibian. Four vestigial legs that end in two or three toes are virtually useless. It is the only amphibian that poses a physical (as opposed to chemical) threat to people.

Strong jaws with a double row of razor-sharp teeth can deliver a savage bite.

Among North American herptiles, only snapping turtles (Chelydridae) have a worse bite.

Although primarily aquatic, amphiumas can leave water temporarily, where they dig burrows in muddy bottoms or invade the burrows of other aquatic animals.

They range through the coastal swamps and drainage ditches of southeastern Virginia, through the Carolinas and Georgia, and on throughout coastal Florida to the Louisiana bayous.

Their fossils have been found at one site in Texas.

Strictly carnivorous, their diet consists chiefly of earthworms, crustaceans and other small invertebrates, which they hunt mostly at night.

Fertilization is internal, and the female lays from 50 to 200 eggs in a single clutch, which she guards until they hatch.

As many as 350 eggs might be produced. Average clutch size of 22 females collected in Louisiana was 201.

The eggs resemble a string of beads and are connected by thin constrictions of an outer sheath that covers the eggs.

Egg incubation can take as long as six months. Nests in Florida have been found in the nest mounds of alligators.

Amphiuma larvae have external gills, but after about four months, these external gills disappear and the lungs begin to work.

One pair of gill slits, with fully functioning internal gills, is retained and never disappears.

Hatchlings are slightly more than 2 inches long at birth and already have all four limbs.

Although biologists have found amphiuma nests out of the water, it is generally thought that the females lay their eggs in the water and that the water subsequently recedes, exposing the eggs.

But some eggs have been found so far from the water’s edge that it seems likely that they were initially laid out of water.

Amphiumas are not considered threatened in the wild.

Their primary predators are wading birds and the mud snake (Farancia abacura), which feeds almost exclusively on amphiumas.

Their flesh is edible, but luckily, few people eat them because the skin is difficult to strip from the flesh. Amphiuma red blood cells are the largest known in vertebrates and are often used in physiological studies in labs and classrooms.

Human encroachment has decimated much of the habitat of Amphiuma, but it is one of few species in which this encroachment has, in some cases, increased their habitats by the building of ponds, lakes and waterways.

Interest in amphibians, such as the amphiuma, continues to rise as people become more aware of this fascinating group of animals.

The amphiumas can be viewed daily at the park’s Streamside and Cypress Swamp habitats.



Tom Gillespie lives in Trinity and is a journalist and public affairs specialist at the North Carolina Zoo. For more information on the zoo’s plant and animal collections, special events and education programs, go to their Web site at www.nczoo.org