Indo-West Pacific: Cocos-Keeling Islands and the South China Sea to the Gilbert Islands, north to the Ryukyu Islands, south to the southern Great Barrier Reef and New Caledonia.

Body yellow-orange above to silvery white below; a prominent blackish bar on head, spotted; iris blackish; opercular area silver; dorsal and anal fin spines and rays yellow, spines with white streak. Spines stout and venomous. Preopercular angle 101°-111°. Cheeks fully covered with strong scales. Midline of thorax scaled; scaled pelvic ridges may interrupt scale row pattern. Low rim of anterior nostril expanded posteriorly into a short, broad triangular flap.

Occurs in shallow, coral-rich areas of clear lagoons and seaward reefs. Individuals up to 7 cm SL forms large schools in shallows, lagoons and outer reef flats, particularly in areas dominated by luxurious growths of Acropora. Adults occur in pairs. Juveniles feed on filamentous algae, adults on algae, tunicates, and sponges.