They have a special affinity for the semi-fluid mud deposits that accumulate in the swampy floodplains of rivers and streams or along the edges of coastal spring-fed rivers. Like all amphiumas, one-toed amphiumas eat small, aquatic invertebrates such as crayfish, annelid worms, insect larvae, and occasionally fish or amphibian larvae.
They have a unique attraction to the semi-liquid mud layers that build up in the marshy flood zones of rivers and streams or near the banks of spring-fed coastal rivers. Like all amphiumas, one-toed amphiumas consume small aquatic invertebrates such as crayfish, annelid worms, insect larvae, and occasionally fish or amphibian larvae.