Known from southern Japan to eastern Philippines. Occurs on rich coral reef slopes, often seen schooling over Acropora fields. Adults move about openly when in large schools and may swim long distances to feed. Where less common, they form pairs that stay near the seabed and are more wary. Juveniles hide amongst coral branches. Readily identified by their bright yellow-orange colour and black and white head. Normally with a distinctive large black blotch on sides, but this is highly variable in size and shape from being absent to very large or double. Often abnormalities are on one side only. Length to 25cm.