A Red Sea endemic, pale grey with a black mask across the eyes and a black patch around the pectoral fin.
To 30 cm. The mask is the whole identification: a bold black mask covering the eyes and running across the face, and a second dark patch around the base of the pectoral fin and the gill opening, against a pale grey to whitish body that darkens towards the tail. The build is typical of its genus — heavy, rounded, inflatable, blunt-headed, with a fused beak, no pelvic fins and finely prickly skin.
The blackspotted puffer is the fish it is compared with, and the difference is clean: this one has a mask and no black spots, that one is covered in scattered small black spots and comes in grey, yellow and two-tone forms. Geography also settles it, because in the Red Sea this is the only one present.
That last point is also the taxonomic question. WoRMS accepts this as a good species. FishBase notes that some authors treat it as the same species as the blackspotted puffer, in which case it would be the Red Sea form of a much wider Indo-Pacific fish. As things stand it is a valid species and effectively a Red Sea endemic.
It lives on coral-rich fringing reef, shallow, roughly to 30 m; no source consulted gives a firm depth range. It is solitary, slow and approachable, and feeds on coral, sponges and hard-shelled invertebrates. It is poisonous to eat and harmless to touch.
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.