Indo-Pacific: Red Sea and East African coast to the Line and Society Islands, north to the Ryukyu and Bonin Islands, south to New Caledonia and Tonga; throughout Micronesia.

Juveniles are brown with a diffuse black blotch with lavender speckles on rear base of the dorsal fin; adults loose the lavender speckles and range from a light grayish brown to black in color. Additionally, adults have bodies with darker scale outlines; blue spot at center of scales on head, body and fin sheaths; mostly pale blue suborbital scales. Indian Ocean specimens with distinct pale-edged black ocellus at the base of last few dorsal rays, extending to the back.

Very broad preorbital-suborbital region, its greatest depth greater than eye diameter in larger than 50 mm specimens. A territorial species commonly found in coral reef areas with dead staghorn corals. Feeds on filamentous algae supported by these dead corals.

Frequently charge human intruders without hesitation, sometimes taking painful nips which are mildly alarming when unexpected. Particularly aggressive during reproductive periods. Emit a clicking noise during aggressive encounters.