Indo-Pacific: East Africa, including the Mascarene Islands to the Tuamoto Islands, north to southern Japan, south to Lord Howe and Rapa islands.

Dark brown (body in life with fine pale blue-green longitudinal lines following scale rows, becoming dots anteriorly on body and on head).

Occurs in coral-rich areas of lagoon and seaward reefs. Graze on algae, usually in groups of 20 individuals. Adults usually in small groups and sometimes schooling. Juveniles solitary and usually among corals. Its numerous, small pharyngeal teeth may have evolved in response to a shift in diet from macroalgae to filamentous algae