Inhabits streams and lagoons with sandy to muddy bottom. Forages by plunging its protrusible mouth into the sandy or muddy bottom, filling it with sediment, and sorting out food inside the mouth. The bulk of the mouthful is expelled through the opercular openings and the mouth, producing a cloud of sediment (substrate sifting). This feeding mode leaves a series of pits and mounds on the bottom. Feeds on insect larvae, crustaceans, plant debris and loose scales (Ref. 40396). Discourages piranha attacks by watching the predator, a tactic used when 2-5 fish feed in groups and the individuals take turns as the "watchman". Confronts an approaching piranha by charging towards the predator with an open mouth and erect dorsal fin (Ref. 9080).