A heavy blue-green parrotfish with a squared-off head, and it bites living coral.
Terminal males reach about 70 cm and are blue-green with a nearly vertical forehead, a blue-green beak and pink or salmon markings around the mouth and pectoral fins. Initial-phase fish are dark grey-brown with a paler tail. The squared head and the size separate it from the smaller parrotfishes on the same reef.
It scrapes and bites both dead substrate and living coral, taking rock with each bite and passing it as sand, and is one of the larger contributors to reef sediment here. Terminal males hold territories with several females. At night it sleeps in a crevice inside a mucus envelope, which appears to mask its scent from nocturnal predators; night divers find them wrapped this way regularly. Recorded from about 3 to 40 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.