Adults inhabit shallow coral reef flats. Found in rivers (Ref. 12792, 48637). Occurs in small schools (usually less than 10 individuals). Juveniles gather in larger numbers in corals with algae-grown at their bases (Ref. 48637). Initially, they browse on fine textured, e.g. filamentous algae, switching to coarser algae with increasing size. Both adults and juveniles are diurnal feeders (Ref. 4666). Fry are marketed fresh, pickled in brine or made into fish paste (Ref. 9813). Can inflict painful stings (Ref. 4690).