Grey reef shark

Grey reef shark
Conservation status
Endangered  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Subdivision:	Selachimorpha
Order:	Carcharhiniformes
Family:	Carcharhinidae
Genus:	Carcharhinus
Species:	C. amblyrhynchos
Binomial name
Carcharhinus amblyrhynchos (Bleeker, 1856)
Range of the grey reef shark
Synonyms
Carcharias amblyrhynchos Bleeker, 1856 Carcharias menisorrah* Müller & Henle, 1839 Carcharias nesiotes Snyder, 1904 Carcharhinus wheeleri Garrick, 1982 Galeolamna coongoola Whitley, 1964 *ambiguous synonym

The grey reef shark or gray reef shark (Carcharhinus amblyrhynchos, sometimes misspelled amblyrhynchus or amblyrhinchos)^[2] is a species of requiem shark, in the family Carcharhinidae. One of the most common reef sharks in the Indo-Pacific, it is found as far east as Easter Island and as far west as South Africa. This species is most often seen in shallow water near the drop-offs of coral reefs. It has the typical "reef shark" shape, with a broad, round snout and large eyes. It can be distinguished from similar species by the plain or white-tipped first dorsal fin, the dark tips on the other fins, the broad, black rear margin on the tail fin, and the lack of a ridge between the dorsal fins. Most individuals are less than 1.88 m (6.2 ft) long.

The grey reef shark is a fast-swimming, agile predator that feeds primarily on free-swimming bony fishes and cephalopods. Its aggressive demeanor enables it to dominate many other shark species on the reef, despite its moderate size. Many grey reef sharks have a home range on a specific area of the reef, to which they continually return. However, they are social rather than territorial. During the day, these sharks often form groups of five to 20 individuals near coral reef drop-offs, splitting up in the evening as the sharks begin to hunt. Adult females also form groups in very shallow water, where the higher water temperature may accelerate their growth or that of their unborn young. Like other members of its family, the grey reef shark is viviparous, meaning the mother nourishes her embryos through a placental connection. Litters of one to six pups are born every other year.

The grey reef shark was the first shark species known to perform a threat display, a stereotypical behavior warning that it is prepared to attack.^[3] The display involves a "hunched" posture with characteristically dropped pectoral fins, and an exaggerated, side-to-side swimming motion. Grey reef sharks often do so if they are followed or cornered by divers to indicate they perceive a threat. This species has been responsible for a number of attacks on humans, and should be treated with caution, especially if it begins to display. It has been caught in many fisheries and is susceptible to local population depletion due to its low reproduction rate and limited dispersal. As a result, the International Union for Conservation of Nature has assessed this species as endangered.