Black head, white throat, yellow dorsal fin.
Size : 23 cm
Habitat : Interior and outreefs, 0.5-25 m. Adults usually in groups, sometimes in very large schools which move as a feeding consort usually in low depths above the reef. Grazes on algae. Can crossbreed with A. nigricans. The hybrids have no white throat spot.
Distribution : East Africa to Burma and Andaman Sea, Christmas Islands, Bali and Komodo.