This is a classically shaped requiem shark. Like many species in the genus Carcharhinus, it is dark grey on the dorsal surface and paler, almost white on the ventral side. It can be distinguished from other species in the genus by the characteristically dark margin on the entire trailing edge of the caudal fin. In the Western Indian Ocean and Red Sea populations it has a white-edged first dorsal fin. This population has been described by some as a distinct species (Carcharhinus wheeleri). This species is sometimes mistaken for the blacktip reef shark as they life in similar habitats, but the two species have strikingly different colour patterns. Grey reef sharks are social, gathering in groups during the day and hunting alone at night. They are inquisitive and commonly approach divers. They are also believed to be territorial and have been documented to arch their backs and push their pectoral fins downward and swim in an exaggerated pattern as part of a territorial display. They are strong and potentially dangerous but are not likely to attack humans unless threatened.