It was unknown to science until 1950, when it was collected by herpetologist Wilfred T. Neill, who described it as a new species in 1964.

The one-toed amphiuma is considered aquatic, and ranges in coloration from gray-black to purplish-brown.

It is the smallest species in the genus Amphiuma with the average adult size being 8.5 inches (220 mm).

Its habits are similar to those of the other members of its genus, preferring slow moving or stagnant, shallow water with either muddy bottoms or areas with weedy vegetation.

Its breeding habits are largely unknown and eggs and hatchlings have never been observed.