Occurs in coral-rich areas of lagoon and seaward reefs. Graze on algae, usually in groups of 20 individuals (Ref. 5503, 48637). Feeds efficiently on a lower standing crop mat of more dispersed algae (Ref. 28026). Adults usually in small groups and sometimes schooling. Juveniles solitary and usually among corals (Ref. 48637). Its numerous, small pharyngeal teeth may have evolved in response to a shift in diet from macroalgae to filamentous algae (Ref. 33204).