Longfin Eels are diadromous, that is, they move from marine to fresh waters as juveniles and return to the sea as adults. These eels live in a variety of freshwater and estuarine environments including coastal lagoons, rivers, creeks, swamps, lakes and farm dams.
Longfin eels prefer riverine habitats.
Longfin eels probably spawn in the Coral Sea waters deeper than 300m, although the exact location of spawning grounds remains unknown. Females produce between 5 and 10 million pelagic eggs. Longfin eels enter estuaries mainly in summer and autumn. This migration takes place during spring and summer, and mainly at night. A number of changes occur as they mature.