Widespread Indian Ocean, ranging east to Christmas and Cocos Keeling Islands, and probably Sumatra, but replaced by similar species in Indonesia. Adults usually swim in small to large groups but may congregate in great numbers at times. Usually on shallow reef crests to about 20m depth. Readily identified by the distinctive colouration that is similar from juvenile to adult stages, and distinguishable from similar indonesian species by the white chest, yellow peduncle and black bands in the caudal fin. Length to 20cm.