Black curved lines on white-blue; an obligate coral feeder, so it is only where the coral is.
To about 20 cm, pale blue-white with bold black curved lines sweeping across the body, a black bar through the eye, and black margins to the dorsal, anal and tail fins. Nothing else here carries the same pattern of long concentric curves. Juveniles are similar and are found in the same coral.
It feeds exclusively on hard coral polyps, which ties it directly to coral cover: it is absent from reefs that have lost their hard coral and is a species used as an indicator of reef condition for that reason. Adults are usually in pairs on well-developed slopes. It is uncommon at the Indonesian and Philippine muck destinations because the habitat is wrong, and regular in Papua New Guinea. Recorded from about 3 to 30 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.