Two-toed amphiumas are the most prominent in the Amphiumidae family and the longest salamander species in the United States,[4] that can grow from 39 to 1,042 g (1.4 to 36.8 oz) in mass and from 34.8 to 116 cm (13.7 to 45.7 in) in length.

[4] Amphiumas live in areas of shallow, heavily vegetated water in swamps, bayous, lakes, and ponds, as well as wet prairies.

They are primarily found in the littoral zones where fish and crayfish are most abundant and vegetation is floating, on logs, or submerged.

Females lay about 200 eggs in a damp cavity beneath debris, close to standing water, and they remain coiled around them during incubation (which lasts around five months).

[14] In a series of three studies conducted in northern Florida, two-toed amphiuma eggs hatched in response to inundation with water, can stand without feeding for 125 days by using resources from their yolk reserves, and the eggs can retain a period of no growth and still survive after 110 days on a moist substrate.

[15] A study depicted seasonal lipid storage increases in males' testicular region and females' liver.

[16] Their hunting behavior is not thoroughly understood, but they are believed to forage actively for food and to wait under debris and in burrows for prey to approach them.