A pale crescent behind the eye that can be switched between yellow and dark brown.
To about 25 cm, grey-brown above and pale below with a curved band running from behind the eye down to the pectoral fin base — the boomerang — which is yellow in some fish and dark brown in others, and which a single fish can change. A second pale band runs from the mouth to below the eye.
It works rubble and sand for urchins, crustaceans and molluscs, blowing water at the substrate to turn small pieces over, and shelters in a crevice it returns to. It is less aggressive than the larger triggerfishes and does not defend a nest against divers in the same way. It is a common fish on rubble slopes across the region. Recorded from about 3 to 45 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.