A dark boxfish covered in pale spots, with a pursed mouth it uses to blow jets of water into sand to uncover worms.
To 47 cm, commonly 20, so most seen are well under half the maximum. The body is a rigid roughly triangular bony box, blackish, covered in numerous small white spots. There are no horns above the eyes, which is the structural difference from the cowfishes. The lips and the bases of the fins are blackish, there is usually a pale area around the pectoral base, and the rear edge of the tail is narrowly white with a blackish band inside it. The lips protrude in a pursed pout. It swims by sculling with the dorsal, anal and pectoral fins and hovers nose-down.
The spotted trunkfish is the confusion and the contrast is inverted: larger, more widely spaced dark spots on a pale ground there, small white spots on a dark ground here.
It feeds by blowing jets of water into sand to expose buried worms, crustaceans and molluscs, which is why it is so often seen hovering nose-down over open sand. It is slow, approachable, alone or in pairs, and has been recorded to about 50 m though it is usually on shallow reef.
When excited it releases a skin toxin that kills other fish in an enclosed volume. In open water it is harmless. Some authorities place it in a different genus, Rhinesomus; it is the same fish.
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.