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 preference for the semi-liquid mud deposits that accumulate in the swampy flood areas of rivers and streams or along the edges of coastal spring-fed rivers. Similar to all amphiumas, one-toed amphiumas feed on small aquatic invertebrates like crayfish, annelid worms, insect larvae, and sometimes fish or amphibian larvae.