The grey reef shark is a fast-swimming, agile predator that feeds primarily on free-swimming bony fishes and cephalopods.

Like other members of its family, the grey reef shark is viviparous, meaning the mother nourishes her embryos through a placental connection.

It has been caught in many fisheries and is susceptible to local population depletion due to its low reproduction rate and limited dispersal.

Dutch ichthyologist Pieter Bleeker first described the grey reef shark in 1856 as Carcharias (Prionodon) amblyrhynchos, in the scientific journal Natuurkundig Tijdschrift voor Nederlandsch-Indië.

It was originally distinguished from the grey reef shark by a white tip on the first dorsal fin, a shorter snout, and one fewer upper tooth row on each side.

[8] The grey reef shark has a streamlined, moderately stout body with a long, blunt snout and large, round eyes.

[9] Individuals from the western Indian Ocean have a narrow, white margin at the tip of the first dorsal fin; this trait is usually absent from Pacific populations.

[5] Grey reef sharks that spend time in shallow water eventually darken in color, due to tanning.

In the Indian Ocean, it occurs from South Africa to India, including Madagascar and nearby islands, the Red Sea, and the Maldives.

In the Pacific Ocean, it is found from Southern China to northern Australia and New Zealand, including the Gulf of Thailand, the Philippines, and Indonesia.

[2] They are found over continental and insular shelves, preferring the leeward (away from the direction of the current) sides of coral reefs with clear water and rugged topography.

[13] On the infrequent occasions when they swim in oceanic waters, grey reef sharks often associate with marine mammals or large pelagic fishes, such as sailfish (Istiophorus platypterus).

[9] At Rangiroa Atoll in French Polynesia, great hammerheads (Sphyrna mokarran) feed opportunistically on grey reef sharks that are exhausted from pursuing mates.

[19][20] Grey reef sharks feed mainly on bony fishes, with cephalopods such as squid and octopus being the second-most important food group, and crustaceans such as crabs and lobsters making up the remainder.

[21] These sharks hunt individually or in groups, and have been known to pin schools of fish against the outer walls of coral reefs for feeding.

Females on the Great Barrier Reef mature at 11 years of age, later than at other locations, and at a slightly larger size.

[4] At Rangiroa, groups of around 30 sharks spend the day together in a small part of their collective home range, dispersing at night into shallower water to forage for food.

[26] Little evidence of territoriality is seen in the grey reef shark; individuals tolerate others of their species entering and feeding within their home ranges.

[28] Off Hawaii, individuals may stay around the same part of the reef up to three years,[29] while at Rangiroa, they regularly shift their locations up to 15 km (9.3 mi).

In the northwestern Hawaiian Islands, large numbers of pregnant females have been observed slowly swimming in circles in shallow water, occasionally exposing their dorsal fins or backs.

Near reef drop-offs, loose aggregations of five to 20 sharks form in the morning and grow in number throughout the day before dispersing at night.

The display consists of the shark raising its snout, dropping its pectoral fins, arching its back, and curving its body laterally.

[3] Grey reef sharks are often curious about divers when they first enter the water and may approach quite closely, though they lose interest on repeat dives.

This species will also attack if pursued or cornered, and divers should immediately retreat (slowly and always facing the shark) if it begins to perform a threat display.

[3] Although of modest size, they are capable of inflicting significant damage: during one study of the threat display, a grey reef shark attacked the researchers' submersible multiple times, leaving tooth marks in the plastic windows and biting off one of the propellers.

[30] Although still abundant in pristine sites, grey reef sharks are susceptible to localized depletion due to their slow reproductive rate, specific habitat requirements, and tendency to stay within a certain area.

[32] One possible avenue for conservation is ecotourism, as grey reef sharks are suitable for shark-watching ventures, and profitable diving sites now enjoy protection in many countries, such as the Maldives.