Asian Diver (English)

Diving by Numbers

- By: Shark Business

GEOGRAPHIC­AL DISTRIBUTI­ON

This species is wide-ranging in the Indo-Pacific, occurring along the east coast of Africa from South Africa to the Red Sea, Indian Ocean islands, northern Indian Ocean, including India, Sri Lanka, Myanmar, Vietnam, the Philippine­s, Australia, New Guinea and Polynesia, Melanesia, Micronesia to the Hawaiian Islands and Pitcairn group. The species is also found in the eastern Pacific, Cocos Islands, Galápagos and Panama to Costa Rica

BUCCAL PUMPING

One of only a few requiem sharks that does not have to continuous­ly swim in order to breathe, the whitetip reef shark uses a method known as buccal pumping to pump water into its mouth and over its gills, enabling it to spend long periods of time resting in caves or on the seabed

SITE FIDELITY

Individual­s of this species maintain a small home range for months or even years at a time and often return to the same place day after day to rest

HABITAT

Commonly found resting along the bottom in clear, shallow water surroundin­g coral reefs, where it is capable of lying motionless for long periods of time. Will often form groups and rest on sandy patches, under ledges or in caves during the daytime, but at night transforms into an active and efficient hunter that patrols the reef and rubble areas in search of prey. Most common at depths between 8–40 metres but has been recorded at 330 metres. Rarely seen at the surface

TOURISM

A common sight on dives in the Pacific, where individual­s are normally easy to spot resting on open sandy areas at depths around 20–30 metres. Divers attempting to get close to them must move slowly, as they do not like to be approached and will normally move away when disturbed. To see this species at its most active, divers must visit Cocos Island in Costa Rica, where the sharks have learnt to utilise divers’ torches to help them locate their prey, and can be seen in large numbers at night hunting on the reef

REPRODUCTI­ON

Like other members of its family, the whitetip reef shark is viviparous, meaning the embryos are nourished via a placenta-like like attachment after exhausting their initial yolk supply. After a gestation period of approximat­ely 5 months, 1–5 pups are born measuring 52–60cm in length. Mating has been observed in the wild and in captivity and the reproducti­ve cycle is biennial

WHITE TIP

The whitetip reef shark earns its name from its distinctiv­e white tips on its first dorsal and upper caudal fins. These markings sometimes cause the species to be mistaken for the silvertip shark, although on close inspection the species are visually quite different

DIET

This shark is a specialist at catching benthic prey hiding in caves and crevices at night. Its slender body enables it to wriggle into tight spaces that are inaccessib­le to other reef sharks where it targets bony fishes, octopuses, lobsters and crabs

PREDATORS

Potential predators include large sharks such as the tiger shark and Galápagos shark, while smaller individual­s and juveniles have also been found inside the stomach of other large fish such as the giant grouper (Epinephelu­s lanceolatu­s)

SNOUT, JAWS AND TEETH

The head is flattened with a broadly rounded and blunt snout. The mouth has a distinct downward slant and the jaws contain 42–50 rows of teeth in the upper jaw and 42–48 rows in the lower jaw. Each tooth has a single narrow, smooth-edged cusp at the centre, flanked by a pair of much smaller cusplets

 ??  ?? Atlantic OceanPacif­ic Ocean52–60 centimetre­sNewborn pups measure aroundMout­hSpiracleG­illWater FlowGill SlitArea of distributi­on
Atlantic OceanPacif­ic Ocean52–60 centimetre­sNewborn pups measure aroundMout­hSpiracleG­illWater FlowGill SlitArea of distributi­on
 ??  ?? Bony FishCrabSi­lvertip SharkOctop­usLobsterG­iant GrouperTig­er SharkGaláp­agos Shark
Bony FishCrabSi­lvertip SharkOctop­usLobsterG­iant GrouperTig­er SharkGaláp­agos Shark

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