Grey reef shark

Last updated

Grey reef shark
Grey5b.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Carcharhiniformes
Family: Carcharhinidae
Genus: Carcharhinus
Species:
C. amblyrhynchos
Binomial name
Carcharhinus amblyrhynchos
(Bleeker, 1856)
Cypron-Range Carcharhinus amblyrhynchos.svg
Range of the grey reef shark
Synonyms

Carcharias amblyrhynchosBleeker, 1856
Carcharias menisorrah* Müller & Henle, 1839
Carcharias nesiotesSnyder, 1904
Carcharhinus wheeleriGarrick, 1982
Galeolamna coongoolaWhitley, 1964
*ambiguous synonym

Contents

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.

Taxonomy and phylogeny

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 metres (4.9 ft)-long female from the Java Sea. [4] 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. [2]

In older literature, the scientific name of this species was often given as C. menisorrah. [5] 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. [6] 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). [7] This interpretation was supported by a 1992 allozyme phylogenetic analysis by Lavery. [8]

Description

Identifying features of the grey reef shark include dark edges on all fins except for the first dorsal fin. Grey reef shark2.jpg
Identifying features of the grey reef shark include dark edges on all fins except for the first dorsal fin.

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). [4]

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. [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. [10] Most grey reef sharks are less than 1.9 m (6.2 ft) long. [4] The maximum reported length is 2.6 m (8.5 ft) and the maximum reported weight is 33.7 kg (74 lb). [9]

Distribution and habitat

Coral reef drop-offs are favored habitat for grey reef sharks. Greyreefshark2.JPG
Coral reef drop-offs are favored habitat for grey reef sharks.

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. [4] [9] 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. [1]

Generally a coastal, shallow-water species, grey reef sharks are mostly found in depths less than 60 m (200 ft). [11] However, they have been known to dive to 1,000 m (3,300 ft). [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. They are frequently found near the drop-offs at the outer edges of the reef, particularly near reef channels with strong currents, [12] and less commonly within lagoons. On occasion, this shark may venture several kilometers out into the open ocean. [4] [11]

Biology and ecology

A female grey reef shark off Wake Island - this species is one of the most common sharks on Indo-Pacific reefs. Carcharhinus amblyrhynchos wake.jpg
A female grey reef shark off Wake Island - this species is one of the most common sharks on Indo-Pacific reefs.

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. [3] 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. [4] 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. [11] 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). [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). 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. [14] Rainbow runners (Elagatis bipinnulata) have been observed rubbing against grey reef sharks, using the sharks' rough skin to scrape off parasites. [15]

Grey reef sharks are themselves prey for larger sharks, such as the silvertip shark. [9] At Rangiroa Atoll in French Polynesia, great hammerheads (Sphyrna mokarran) feed opportunistically on grey reef sharks that are exhausted from pursuing mates. [16] Known parasites of this species include the nematode Huffmanela lata and several copepod species that attach to the sharks' skin, [17] [18] and juvenile stages of the isopods Gnathia trimaculata and G. grandilaris that attach to the gill filaments and septa (the dividers between each gill). [19] [20]

Feeding

The lower teeth of the grey reef shark are narrower than upper teeth. Carcharhinus amblyrhynchos JNC1111 Mouth.JPG
The lower teeth of the grey reef shark are narrower than upper teeth.

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. The larger sharks take a greater proportion of cephalopods. [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. [15] Hunting groups of up to 700 grey reef sharks have been observed at Fakarava atoll in French Polynesia. [22] [23] They excel at capturing fish swimming in the open, and they complement hunting whitetip reef sharks, which are more adept at capturing fish inside caves and crevices. [4] Their sense of smell is extremely acute, being capable of detecting one part tuna extract in 10 billion parts of sea water. [14] In the presence of a large quantity of food, grey reef sharks may be roused into a feeding frenzy; in one documented frenzy caused by an underwater explosion that killed several snappers, one of the sharks involved was attacked and consumed by the others. [24]

Life history

During mating, the male grey reef shark bites at the female's body or fins to hold onto her for copulation. [14] Like other requiem sharks, it is viviparous; once the developing embryos exhaust their supply of yolk, the yolk sac develops into a placental connection that sustains them to term. Each female has a single functional ovary (on the right side) and two functional uteri. One to four pups (six in Hawaii) are born every other year; the number of young increases with female size. Estimates of the gestation period range from 9 to 14 months. Parturition is thought to take place from July to August in the Southern Hemisphere and from March to July in the Northern Hemisphere. However, females with "full-term embryos" have also been reported in the fall off Enewetak. The newborns measure 45–60 cm (18–24 in) long. Sexual maturation occurs around seven years of age, when the males are 1.3–1.5 m (4.3–4.9 ft) long and females are 1.2–1.4 m (3.9–4.6 ft) long. Females on the Great Barrier Reef mature at 11 years of age, later than at other locations, and at a slightly larger size. The lifespan is at least 25 years. [4] [21] [25]

Behavior

Grey reef sharks become more active as night approaches. C. amblyrynchus.JPG
Grey reef sharks become more active as night approaches.

Grey reef sharks are active at all times of the day, with activity levels peaking at night. [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. Their home range is about 0.8 km2 (0.31 sq mi). [26] At Enewetak in the Marshall Islands, grey reef sharks from different parts of the reef exhibit different social and ranging behaviors. Sharks on the outer ocean reefs tend to be nomadic, swimming long distances along the reef, while those around lagoon reefs and underwater pinnacles stay within defined daytime and nighttime home ranges. [27] Where strong tidal currents occur, grey reef sharks move against the water, toward the shore with the ebbing tide and back out to sea with the rising tide. This may allow them to better detect the scent of their prey, or afford them the cover of turbid water in which to hunt. [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). [28] Individual grey reef sharks at Enewetak become highly aggressive at specific locations, suggesting they may exhibit dominant behavior over other sharks in their home areas. [3]

Sociality

Grey reef sharks often group together during the day, such as this aggregation at Kure Atoll in the Hawaiian Islands. Carcharhinus amblyrhynchos kure atoll.jpg
Grey reef sharks often group together during the day, such as this aggregation at Kure Atoll in the Hawaiian Islands.

Social aggregation is well documented in grey reef sharks. 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. These groups last from 11:00 to 15:00, corresponding to peak daylight hours. [29] Similarly, at Sand Island off Johnston Atoll, females form aggregations in shallow water from March to June. The number of sharks per group differs from year to year. Each day, the sharks begin arriving at the aggregation area at 09:00, reaching a peak in numbers during the hottest part of the day in the afternoon, and dispersing by 19:00. Individual sharks return to the aggregation site every one to six days. These female sharks are speculated to be taking advantage of the warmer water to speed their growth or that of their embryos. The shallow waters may also enable them to avoid unwanted attention by males. [10]

Off Enewetak, grey reef sharks exhibit different social behaviors on different parts of the reef. Sharks tend to be solitary on shallower reefs and pinnacles. 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. In level areas, sharks form polarized schools (all swimming in the same direction) of around 30 individuals near the sea bottom, arranging themselves parallel to each other or slowly swimming in circles. Most individuals within polarized schools are females, and the formation of these schools has been theorized to relate to mating or pupping. [26] [27]

Threat display

The posture of a grey reef shark during normal swimming (right) and a threat display (left) - the bottom line shows the shark's swimming pattern. Shark threat display.png
The posture of a grey reef shark during normal swimming (right) and a threat display (left) - the bottom line shows the shark's swimming pattern.

The "hunch" threat display of the grey reef shark is the most pronounced and well-known agonistic display (a display directed toward competitors or threats) of any shark. Investigations of this behavior have been focused on the reaction of sharks to approaching divers, some of which have culminated in attacks. The display consists of the shark raising its snout, dropping its pectoral fins, arching its back, and curving its body laterally. While holding this posture, the shark swims with a stiff, exaggerated side-to-side motion, sometimes combined with rolls or figure-8 loops. The intensity of the display increases if the shark is more closely approached or if obstacles are blocking its escape routes, such as landmarks or other sharks. If the diver persists, the shark may either retreat or launch a rapid, open-mouthed attack, slashing with its upper teeth. [3]

Most observed displays by grey reef sharks have been in response to a diver (or submersible) approaching and following it from a few meters behind and above. They also perform the display toward moray eels, and in one instance toward a much larger great hammerhead (which subsequently withdrew). However, they have never been seen performing threat displays toward each other. This suggests the display is primarily a response to potential threats (i.e. predators) rather than competitors. As grey reef sharks are not territorial, they are thought to be defending a critical volume of "personal space" around themselves. Compared to sharks from French Polynesia or Micronesia, grey reef sharks from the Indian Ocean and western Pacific are not as aggressive and less given to displaying. [3]

Human interactions

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. [4] They can become dangerous in the presence of food, and tend to be more aggressive if encountered in open water rather than on the reef. [14] There have been several known attacks on spearfishers, possibly by mistake, when the shark struck at the speared fish close to the diver. 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. [4] Photographing the display should not be attempted, as the flash from a camera is known to have incited at least one attack. [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. The shark consistently launched its attacks from a distance of 6 m (20 ft), which it was able to cover in a third of a second. [15] As of 2008, the International Shark Attack File listed seven unprovoked and six provoked attacks (none of them fatal) attributable to this species. [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. The IUCN has assessed the grey reef shark as endangered; this shark is taken by multispecies fisheries in many parts of its range and used for various products such as shark fin soup and fishmeal. [2] Another threat is the continuing degradation of coral reefs from human development. There is evidence of substantial declines in some populations. Anderson et al. (1998) reported, in the Chagos Archipelago, grey reef shark numbers in 1996 had fallen to 14% of 1970s levels. [31] Robbins et al. (2006) found grey reef shark populations in Great Barrier Reef fishing zones had declined by 97% compared to no-entry zones (boats are not allowed). In addition, no-take zones (boats are allowed but fishing is prohibited) had the same levels of depletion as fishing zones, illustrating the severe effect of poaching. Projections suggested the shark population would fall to 0.1% of pre-exploitation levels within 20 years without additional conservation measures. [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. [6]

Related Research Articles

<span class="mw-page-title-main">Requiem shark</span> Family of sharks

Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes. They are migratory, live-bearing sharks of warm seas and include such species as the bull shark, lemon shark, blacktip shark, and whitetip reef shark.

<span class="mw-page-title-main">Oceanic whitetip shark</span> Species of requiem shark

The oceanic whitetip shark is a large pelagic requiem shark inhabiting tropical and warm temperate seas. It has a stocky body with long, white-tipped, rounded fins. The species is typically solitary, though they may gather in large numbers at food concentrations. Bony fish and cephalopods are the main components of its diet and females give live birth.

<span class="mw-page-title-main">Silky shark</span> Species of fish

The silky shark, also known by numerous names such as blackspot shark, gray whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the family Carcharhinidae, named for the smooth texture of its skin. It is one of the most abundant sharks in the pelagic zone, and can be found around the world in tropical waters. Highly mobile and migratory, this shark is most often found over the edge of the continental shelf down to 50 m (164 ft). The silky shark has a slender, streamlined body and typically grows to a length of 2.5 m. It can be distinguished from other large requiem sharks by its relatively small first dorsal fin with a curving rear margin, its tiny second dorsal fin with a long free rear tip, and its long, sickle-shaped pectoral fins. It is a deep, metallic bronze-gray above and white below.

<span class="mw-page-title-main">Blacktip reef shark</span> Species of shark

The blacktip reef shark is a species of requiem shark, in the family Carcharhinidae, which can be easily identified by the prominent black tips on its fins. Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters. Its exposed first dorsal fin is a common sight in the region. The blacktip reef shark is usually found over reef ledges and sandy flats, though it has also been known to enter brackish and freshwater environments. It typically attains a length of 1.6 m (5.2 ft). Like other sharks, the females are larger than the males.

<span class="mw-page-title-main">Whitetip reef shark</span> Species of shark

The whitetip reef shark is a species of requiem shark, in the family Carcharhinidae, and the only member of its genus. A small shark that does not usually exceed 1.6 m (5.2 ft) in length, this species is easily recognizable by its slender body and short but broad head, as well as tubular skin flaps beside the nostrils, oval eyes with vertical pupils, and white-tipped dorsal and caudal fins. One of the most common sharks found on Indo-Pacific coral reefs, the whitetip reef shark occurs as far west as South Africa and as far east as Central America. It is typically found on or near the bottom in clear water, at a depth of 8–40 m (26–131 ft).

<span class="mw-page-title-main">Copper shark</span> Species of shark

The copper shark, bronze whaler, or narrowtooth shark is a species of requiem shark found mostly in temperate latitudes. It is distributed in a number of separate populations in the northeastern and southwestern Atlantic, off southern Africa, in the northwestern and eastern Pacific, and around Australia and New Zealand, with scattered reports from equatorial regions. The species can be found from brackish rivers and estuaries to shallow bays and harbors, to offshore waters 100 m (330 ft) deep or more. Females are found apart from males for most of the year, and conduct seasonal migrations. A large species reaching 3.3 m (11 ft) long, the copper shark is difficult to distinguish from other large requiem sharks. It is characterized by its narrow, hook-shaped upper teeth, lack of a prominent ridge between the dorsal fins, and plain bronze coloration.

<span class="mw-page-title-main">Dusky shark</span> Species of shark

The dusky shark is a species of requiem shark, in the family Carcharhinidae, occurring in tropical and warm-temperate continental seas worldwide. A generalist apex predator, the dusky shark can be found from the coast to the outer continental shelf and adjacent pelagic waters, and has been recorded from a depth of 400 m (1,300 ft). Populations migrate seasonally towards the poles in the summer and towards the equator in the winter, traveling hundreds to thousands of kilometers. One of the largest members of its genus, the dusky shark reaches more than 4 m (13 ft) in length and 350 kg (770 lb) in weight. It has a slender, streamlined body and can be identified by its short round snout, long sickle-shaped pectoral fins, ridge between the first and second dorsal fins, and faintly marked fins.

<span class="mw-page-title-main">Silvertip shark</span> Species of shark

The silvertip shark is a large species of requiem shark, in the family Carcharhinidae, with a fragmented distribution throughout the tropical Indian and Pacific Oceans. It is often encountered around offshore islands and coral reefs, and has been known to dive to a depth of 800 m (2,600 ft). The silvertip shark resembles a larger and bulkier grey reef shark, but can be easily identified by the prominent white margins on its fins. It attains a maximum length of 3 m (10 ft).

<span class="mw-page-title-main">Blacktip shark</span> Species of shark

The blacktip shark is a species of requiem shark, and part of the family Carcharhinidae. It is common to coastal tropical and subtropical waters around the world, including brackish habitats. Genetic analyses have revealed substantial variation within this species, with populations from the western Atlantic Ocean isolated and distinct from those in the rest of its range. The blacktip shark has a stout, fusiform body with a pointed snout, long gill slits, and no ridge between the dorsal fins. Most individuals have black tips or edges on the pectoral, dorsal, pelvic, and caudal fins. It usually attains a length of 1.5 m (4.9 ft).

<span class="mw-page-title-main">Caribbean reef shark</span> Species of shark

The Caribbean reef shark is a species of requiem shark, belonging to the family Carcharhinidae. It is found in the tropical waters of the western Atlantic Ocean from Florida to Brazil, and is the most commonly encountered reef shark in the Caribbean Sea. With a robust, streamlined body typical of the requiem sharks, this species is difficult to tell apart from other large members of its family such as the dusky shark and the silky shark. Distinguishing characteristics include dusky-colored fins without prominent markings, a short free rear tip on the second dorsal fin, and tooth shape and number.

<span class="mw-page-title-main">Galapagos shark</span> Species of shark

The Galapagos shark is a species of requiem shark, in the family Carcharhinidae, found worldwide. It favors clear reef environments around oceanic islands, where it is often the most abundant shark species. A large species that often reaches 3.0 m (9.8 ft), the Galapagos reef shark has a typical fusiform "reef shark" shape and is very difficult to distinguish from the dusky shark and the grey reef shark. An identifying character of this species is its tall first dorsal fin, which has a slightly rounded tip and originates over the rear tips of the pectoral fins.

<span class="mw-page-title-main">Blacknose shark</span> Species of shark

The blacknose shark is a species of requiem shark, belonging to the family Carcharhinidae, common in the tropical and subtropical waters of the western Atlantic Ocean. This species generally inhabits coastal seagrass, sand, or rubble habitats, with adults preferring deeper water than juveniles. A small shark typically measuring 1.3 m (4.3 ft) long, the blacknose has a typical streamlined "requiem shark" shape with a long, rounded snout, large eyes, and a small first dorsal fin. Its common name comes from a characteristic black blotch on the tip of its snout, though this may be indistinct in older individuals.

<span class="mw-page-title-main">Bignose shark</span> Species of shark

The bignose shark is a species of requiem shark, in the family Carcharhinidae. Distributed worldwide in tropical and subtropical waters, this migratory shark frequents deep waters around the edges of the continental shelf. It is typically found at depths of 90–430 m (300–1,410 ft), though at night it may move towards the surface or into shallower water. The bignose shark is plain-colored and grows to at least 2.7–2.8 m (8.9–9.2 ft) in length. It has a long, broad snout with prominent nasal skin flaps, and tall, triangular upper teeth. Its pectoral fins are long and almost straight, and there is a ridge on its back between the two dorsal fins.

<span class="mw-page-title-main">Creek whaler</span> Species of shark

The creek whaler is a common species of requiem shark, and part of the family Carcharhinidae, endemic to northern Australia. It frequents shallow waters close to shore, including estuaries. This small, stocky shark usually grows to 1.0–1.3 m (3.3–4.3 ft) long and is brownish in color without conspicuous fin markings. It can be identified by its long snout, large, triangular pectoral fins, and large, anteriorly positioned first dorsal fin.

<span class="mw-page-title-main">Spinner shark</span> Species of shark

The spinner shark is a type of requiem shark, in the family Carcharhinidae, named for the spinning leaps it makes as a part of its feeding strategy. This species occurs in tropical and warm temperate waters worldwide, except for in the eastern Pacific Ocean. It is found from coastal to offshore habitats to a depth of 100 m (330 ft), though it prefers shallow water. The spinner shark resembles a larger version of the blacktip shark, with a slender body, long snout, and black-marked fins. This species can be distinguished from the blacktip shark by the first dorsal fin, which has a different shape and is placed further back, and by the black tip on the anal fin. It attains a maximum length of 3 m (9.8 ft).

<span class="mw-page-title-main">Whitecheek shark</span> Species of shark

The whitecheek shark or widemouth blackspot shark is a requiem shark of the family Carcharhinidae, found in the Indo-West Pacific Ocean between latitudes 34°N and 25°S. It can reach a length of 1 m. It feeds mainly on fish, cephalopods, and crustaceans. It is a viviparous species, with the female giving birth to up to four live young.

<span class="mw-page-title-main">Blackspot shark</span> Species of shark

The blackspot shark is a small species of requiem shark in the family Carcharhinidae found in the tropical Indo-West Pacific Ocean between latitudes 24°N and 30°S, from the surface to a depth around 40 m (130 ft). Its length is a little under one meter (yard) and it is not considered to be dangerous to humans. It feeds mainly on fish, crustaceans, and squid. This shark is also caught in small-scale fisheries for human consumption.

<span class="mw-page-title-main">Bluefin trevally</span> Species of fish

The bluefin trevally, also known as the bluefin jack, bluefin kingfish, bluefinned crevalle, blue ulua, omilu, and spotted trevally, is a species of large, widely distributed marine fish classified in the jack family, Carangidae. The bluefin trevally is distributed throughout the tropical waters of the Indian and Pacific Oceans, ranging from Eastern Africa in the west to Central America in the east, including Japan in the north and Australia in the south. The species grows to a maximum known length of 117 centimetres (46 in) and a weight of 43.5 kilograms (96 lb), however is rare above 80 centimetres (31 in). Bluefin trevally are easily recognised by their electric blue fins, tapered snout and numerous blue and black spots on their sides. Juveniles lack these obvious colours, and must be identified by more detailed anatomical features such as fin ray and scute counts. The bluefin trevally inhabits both inshore environments such as bays, lagoons and shallow reefs, as well as deeper offshore reefs, atolls and bomboras. Juveniles prefer shallower, protected waters, even entering estuaries for short periods in some locations.

<span class="mw-page-title-main">Camouflage grouper</span> Species of fish

The camouflage grouper, also known as the blue-tailed cod, camouflage rockcod, small-toothed rockcod, smooth flowery rock-cod, snout-spot grouper or snout-spot rock-cod, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It has a wide Indo-Pacific distribution where it is associated with reefs.

<span class="mw-page-title-main">Coral reef fish</span> Fish which live amongst or in close relation to coral reefs

Coral reef fish are fish which live amongst or in close relation to coral reefs. Coral reefs form complex ecosystems with tremendous biodiversity. Among the myriad inhabitants, the fish stand out as colourful and interesting to watch. Hundreds of species can exist in a small area of a healthy reef, many of them hidden or well camouflaged. Reef fish have developed many ingenious specialisations adapted to survival on the reefs.

References

  1. 1 2 Simpfendorfer, C.; Fahmi, Bin Ali, A.; , D.; Utzurrum, J.A.T.; Seyha, L.; Maung, A.; Bineesh, K.K.; Yuneni, R.R.; Sianipar, A.; Haque, A.B.; Tanay, D.; Gautama, D.A.; Vo, V.Q. (2020). "Carcharhinus amblyrhynchos". IUCN Red List of Threatened Species . 2020: e.T39365A173433550. doi: 10.2305/IUCN.UK.2020-3.RLTS.T39365A173433550.en . Retrieved 19 November 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. 1 2 3 4 Froese, Rainer; Pauly, Daniel (eds.). "Carcharhinus amblyrhynchos". FishBase . April 2009 version.
  3. 1 2 3 4 5 6 Martin, R.A. (March 2007). "A review of shark agonistic displays: comparison of display features and implications for shark-human interactions". Marine and Freshwater Behaviour and Physiology. 40 (1): 3–34. doi: 10.1080/10236240601154872 .
  4. 1 2 3 4 5 6 7 8 9 10 11 Compagno, L.J.V. (1984). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. pp. 459–461. ISBN   978-92-5-101384-7.
  5. 1 2 Randall, J.E.; Hoover, J.P. (1995). Coastal fishes of Oman. University of Hawaii Press. p. 29. ISBN   978-0-8248-1808-1.
  6. 1 2 Fowler, S.L.; Cavanagh, R.D.; Camhi, M.; Burgess, G.H.; Cailliet, G.M.; Fordham, S.V.; Simpfendorfer, C.A. & Musick, J.A. (2005). Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. International Union for Conservation of Nature and Natural Resources. pp. 106–109, 284–285. ISBN   978-2-8317-0700-6.
  7. ↑ Garrick, J.A.F. (1982). Sharks of the genus Carcharhinus. NOAA Technical Report, NMFS Circ. 445.
  8. ↑ Lavery, S. (1992). "Electrophoretic analysis of phylogenetic relationships among Australian carcharhinid sharks". Australian Journal of Marine and Freshwater Research. 43 (1): 97–108. doi:10.1071/MF9920097.
  9. 1 2 3 4 Bester, C. Biological Profiles: Grey Reef Shark Archived 2008-06-04 at the Wayback Machine . Florida Museum of Natural History Ichthyology Department. Retrieved on April 29, 2009.
  10. 1 2 Economakis, A.E.; Lobel, P.S. (1998). "Aggregation behavior of the grey reef shark, Carcharhinus amblyrhynchos, at Johnston Atoll, Central Pacific Ocean". Environmental Biology of Fishes. 51 (2): 129–139. doi:10.1023/A:1007416813214. S2CID   46066734.
  11. 1 2 3 Papastamatiou, Y.P.; Wetherbee, B.M.; Lowe, C.G. & Crow, G.L. (2006). "Distribution and diet of four species of carcharhinid shark in the Hawaiian Islands: evidence for resource partitioning and competitive exclusion". Marine Ecology Progress Series. 320: 239–251. Bibcode:2006MEPS..320..239P. doi: 10.3354/meps320239 .
  12. ↑ Dianne J. Bray, 2011, Grey Reef Shark, Carcharhinus amblyrhynchos, in Fishes of Australia, accessed 25 August 2014, http://www.fishesofaustralia.net.au/Home/species/2881 Archived 2014-12-15 at the Wayback Machine
  13. ↑ Dunn, Ruth E.; Bradley, Darcy; Heithaus, Michael R.; Caselle, Jennifer E.; Papastamatiou, Yannis P. (2022-01-21). "Conservation implications of forage base requirements of a marine predator population at carrying capacity". iScience. 25 (1): 103646. Bibcode:2022iSci...25j3646D. doi:10.1016/j.isci.2021.103646. ISSN   2589-0042. PMC   8728395 . PMID   35024583. S2CID   245303571.
  14. 1 2 3 4 Stafford-Deitsch, J. (1999). Red Sea Sharks. Trident Press. pp. 19–24, 27–32, 74–75. ISBN   978-1-900724-28-9.
  15. 1 2 3 Bright, M. (2000). The Private Life of Sharks: The Truth Behind the Myth. Stackpole Books. pp. 74–76. ISBN   978-0-8117-2875-1.
  16. ↑ Whitty, J. (2007). The Fragile Edge: Diving and Other Adventures in the South Pacific . Houghton Mifflin Harcourt. p.  9. ISBN   978-0-618-19716-3.
  17. ↑ Justine, J. (July 2005). "Huffmanela lata n. sp. (Nematoda: Trichosomoididae: Huffmanelinae) from the shark Carcharhinus amblyrhynchos (Elasmobranchii: Carcharhinidae) off New Caledonia". Systematic Parasitology. 61 (3): 181–184. doi:10.1007/s11230-005-3160-8. PMID   16025207. S2CID   915034.
  18. ↑ Newbound, D.R.; Knott, B. (1999). "Parasitic copepods from pelagic sharks in Western Australia". Bulletin of Marine Science. 65 (3): 715–724.
  19. ↑ Coetzee, M.L.; Smit, N.J.; Grutter, A.S. & Davies, A.J. (February 2009). "Gnathia trimaculata n. sp. (Crustacea: Isopoda: Gnathiidae), an ectoparasite found parasitising requiem sharks from off Lizard Island, Great Barrier Reef, Australia". Systematic Parasitology. 72 (2): 97–112. doi:10.1007/s11230-008-9158-2. PMID   19115084. S2CID   8645018.
  20. ↑ Coetzee, M.L.; Smit, N.J.; Grutter, A.S. & Davies, A.J. (2008). "A New Gnathiid (Crustacea: Isopoda) Parasitizing Two Species of Requiem Sharks from Lizard Island, Great Barrier Reef, Australia". Journal of Parasitology. 94 (3): 608–615. doi:10.1645/ge-1391r.1. PMID   18605791.
  21. 1 2 Wetherbee, B.M.; Crow, C.G. & Lowe, C.G. (1997). "Distribution, reproduction, and diet of the gray reef shark Carcharhinus amblyrhychos in Hawaii". Marine Ecology Progress Series. 151: 181–189. Bibcode:1997MEPS..151..181W. doi: 10.3354/meps151181 .
  22. ↑ "Gombessa IV expedition". Archived from the original on 2020-06-11. Retrieved 2018-10-12.
  23. ↑ Gombessa IV on arte.tv (archive.org)
  24. ↑ Halstead, B.W.; Auerbach, Paul S. & Campbell, D.R. (1990). A Color Atlas of Dangerous Marine Animals. CRC Press. p. 11. ISBN   978-0-8493-7139-4.
  25. ↑ Robbins, W.D. (2006). Abundance, demography and population structure of the grey reef shark (Carcharhinus amblyrhynchos) and the white tip reef shark (Triaenodon obesus) (Fam. Charcharhinidae). PhD thesis, James Cook University.
  26. 1 2 3 Martin, R.A. Coral Reefs: Grey Reef Shark. ReefQuest Centre for Shark Research. Retrieved on April 30, 2009.
  27. 1 2 McKibben J.N.; Nelson, D.R. (1986). "Pattern of movement and grouping of gray reef sharks, Carcharhinus amblyrhyncos, at Enewetak, Marshall Islands". Bulletin of Marine Science. 38: 89–110.
  28. 1 2 Nelson, D.R. (1981). "Aggression in sharks: is the grey reef shark different?". Oceanus. 24: 45–56.
  29. 1 2 Taylor, L.R. (1993). Sharks of Hawaii: Their Biology and Cultural Significance. University of Hawaii Press. pp. 21–24. ISBN   978-0-8248-1562-2.
  30. ↑ ISAF Statistics on Attacking Species of Shark. International Shark Attack File, Florida Museum of Natural History, University of Florida. Retrieved on May 1, 2009.
  31. ↑ Anderson, R.C.; Sheppard, C.; Spalding, M. & Crosby, R. (1998). "Shortage of sharks at Chagos". Shark News. 10: 1–3.
  32. ↑ Robbins, W.D.; Hisano, M.; Connolly, S.R. & Choat, J.H. (2006). "Ongoing collapse of coral reef shark populations". Current Biology. 16 (23): 2314–2319. doi: 10.1016/j.cub.2006.09.044 . PMID   17141612.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.