The one reef shark here that can lie still on the bottom and keep breathing.
To about 2 m, slender and grey-brown with white tips on the first dorsal fin and the upper tail lobe, a broad flattened snout and small oval eyes with prominent skin flaps above them. The blacktip reef shark has black fin tips; the grey reef shark has a black-edged tail and no white dorsal tip.
Most requiem sharks must swim to pass water over the gills; this one can pump water and so spends the day resting in caves, under ledges and on sand in groups of two to a dozen, often returning to the same shelter. It hunts at night, working into crevices after octopus, crabs and reef fish, sometimes several sharks pushing into the same hole. It is not aggressive towards divers and generally moves off a resting spot if approached directly, so photographs come from stopping short. Recorded from about 3 to 45 m; numbers here are much reduced by fishing and it is listed as vulnerable.
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.