Grey reef shark (Carcharhinus amblyrhynchos)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Elasmobranchii · Order: Carcharhiniformes · Family: Carcharhinidae · Genus: Carcharhinus.

Accepted name: Carcharhinus amblyrhynchos · Authority: (Bleeker, 1856) · Taxonomic status: accepted · AphiaID: 217337.

Synonyms and superseded combinations recorded for this taxon: Carcharhinus amblyrhinchos (Bleeker, 1856); Carcharhinus amblyrhynchus (Bleeker, 1856); Carcharhinus wheeleri Garrick, 1982; Carcharias amblyrhynchos Bleeker, 1856; Carcharias nesiotes Snyder, 1904; Carcharinus amblyrhynchos (Bleeker, 1856); Carcharinus amblyrhynchus (Bleeker, 1856); Carcharinus amblyrhyncus (Bleeker, 1856); Galeolamna coongoola Whitley, 1964; Galeolamna fowleri Whitley, 1944; Galeolamna tufiensis Whitley, 1949.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=217337 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Carcharhinus amblyrhynchos. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 255 cm · Depth range: 0–1000 m · Habitat zone: reef-associated · Body shape: fusiform / normal · Vulnerability index: 85 of 100 · Fishery importance: minor commercial · Aquarium trade: never/rarely.

FishBase notes: Occurs on continental and insular shelves and oceanic waters adjacent to them (Ref. 244). Common on coral reefs, often in deeper areas near drop-offs to the open sea, in atoll passes, and in shallow lagoons adjacent to areas of strong currents (Ref. 244). Coastal-pelagic near the bottom, near drop-offs at 1-275 m (Ref. 58302). Forms daytime schools or aggregations in favored areas (Ref. 244). Although active during the day, it is more active nocturnally (Ref. 244). Viviparous, with 1-6 pups (Ref. 37816). Feeds on reef fishes, squids, octopi, crabs, lobsters and shrimps (Ref. 244, 5578). Tends to be aggressive under baited conditions (Ref. 6871) and readily enters into a frenzy feeding pattern, at which time it may become quite dangerous. Repeatedly incriminated in human attacks. Utilized for human consumption, fishmeal, and other shark products. Minimum depth from Ref. 6871. Maximum length of female taken from Ref. 5213.

Source: FishBase species summary (SpecCode 861) — https://www.fishbase.se/summary/Carcharhinus-amblyrhynchos.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

219,152 georeferenced occurrence records for Carcharhinus amblyrhynchos are published through GBIF from 54 countries or marine areas. The map above plots 189 distinct locations from a sample of 3,000 records, omitting 10 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Australia (214,971); United States Minor Outlying Islands (1,641); French Polynesia (333); Maldives (297); New Caledonia (265).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2418064) — https://www.gbif.org/occurrence/search?taxon_key=2418064&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=217337 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Carcharhinus amblyrhynchos (Bleeker, 1856) as Endangered (code EN). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 39365) — https://www.iucnredlist.org/species/39365/0; GBIF IUCN Red List category endpoint (taxonKey 2418064) — https://api.gbif.org/v1/species/2418064/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

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. 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.

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. Later authors moved this species to the genus Carcharhinus. The type specimen was a 1.5 m-long female from the Java Sea. Other common names used for this shark around the world include black-vee whaler, bronze whaler, Fowler's whaler shark, graceful shark, graceful whaler shark, grey shark, grey whaler shark, longnose blacktail shark, school shark, and shortnose blacktail shark. Some of these names are also applied to other species.

In older literature, the scientific name of this species was often given as C. menisorrah. The blacktail reef shark (C. wheeleri), native to the western Indian Ocean, is now regarded as the same species as the grey reef shark by most authors. 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. Based on morphological characters, vertebral counts, and tooth shapes, Garrick (1982) concluded the grey reef shark is most closely related to the silvertip shark (C. albimarginatus). This interpretation was supported by a 1992 allozyme phylogenetic analysis by Lavery.

Fossil teeth of the gray reef shark are known from the Late Miocene of Brunei, representing the oldest known record of the species.

The grey reef shark has a streamlined, moderately stout body with a long, blunt snout and large, round eyes. The upper and lower jaws each have 13 or 14 teeth (usually 14 in the upper and 13 in the lower). The upper teeth are triangular with slanted cusps, while the bottom teeth have narrower, erect cusps. The tooth serrations are larger in the upper jaw than in the lower. The first dorsal fin is medium-sized, and no ridge runs between the second dorsal fin and it. The pectoral fins are narrow and falcate (sickle-shaped).

The coloration is grey above, sometimes with a bronze sheen, and white below. The entire rear margin of the caudal fin has a distinctive, broad, black band. Dusky to black tips are on the pectoral, pelvic, second dorsal, and anal fins. 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. Grey reef sharks that spend time in shallow water eventually darken in color, due to tanning. Most grey reef sharks are less than 1.9 m long. The maximum reported length is 2.6 m and the maximum reported weight is 33.7 kg.

The grey reef shark is native to the Indian and Pacific Oceans. 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. This species has also been reported from numerous Pacific islands, including American Samoa, the Chagos Archipelago, Easter Island, Christmas Island, the Cook Islands, the Marquesas Islands, the Tuamotu Archipelago, Guam, Kiribati, the Marshall Islands, Micronesia, Nauru, New Caledonia, the Marianas Islands, Palau, the Pitcairn Islands, Samoa, the Solomon Islands, Tuvalu, the Hawaiian Islands, and Vanuatu.

Generally a coastal, shallow-water species, grey reef sharks are mostly found in depths less than 60 m. However, they have been known to dive to 1000 m. 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. They are frequently found near the drop-offs at the outer edges of the reef, particularly near reef channels with strong currents, and less commonly within lagoons. On occasion, this shark may venture several kilometers out into the open ocean.

Along with the blacktip reef shark (C. melanopterus) and the whitetip reef shark (Triaenodon obesus), the grey reef shark is one of the three most common sharks inhabiting Indo-Pacific reefs. They actively expel most other shark species from favored habitats, even species larger in size. In areas where this species co-exists with the blacktip reef shark, the latter species occupies the shallow flats, while the former stays in deeper water. Areas with a high abundance of grey reef sharks tend to contain few sandbar sharks (C. plumbeus), and vice versa; this may be due to their similar diets causing competitive exclusion. The consumptive influence of grey reef sharks on reef fish communities is likely to vary depending on whether sharks forage within the reef environment, or on pelagic resources (like they have been observed to do at Palmyra Atoll).

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). One account has around 25 grey reef sharks following a large pod of bottlenose dolphins (Tursiops sp.), along with 25 silky sharks (C. falciformis) and a single silvertip shark. Rainbow runners (Elagatis bipinnulata) have been observed rubbing against grey reef sharks, using the sharks' rough skin to scrape off parasites.

Grey reef sharks are themselves prey for larger sharks, such as the silvertip shark. At Rangiroa Atoll in French Polynesia, great hammerheads (Sphyrna mokarran) feed opportunistically on grey reef sharks that are exhausted from pursuing mates. Known parasites of this species include the nematode Huffmanela lata and several copepod species that attach to the sharks' skin, and juvenile stages of the isopods Gnathia trimaculata and G. grandilaris that attach to the gill filaments and septa (the dividers between each gill).

Grey reef sharks feed mainly on bony fishes and cephalopods such as squid and octopuses being the second-most important food group, and crustaceans such a

Source: Wikipedia: Grey reef shark — https://en.wikipedia.org/wiki/Grey_reef_shark (CC BY-SA 4.0). Accessed 2026-09-23.

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