Shark Species - The Great Fiji Shark Count

Whale shark

The whale shark, Rhincodon typus, is a slow-moving filter feeding shark. It is the largest extant fish species. The largest confirmed individual had a length of 12.65 metres (41.50 ft) and a weight of more than 21.5 tonnes (47,000 lb), and there are unconfirmed reports of considerably larger whale sharks. This distinctively-marked fish is the only member of its genus Rhincodon and itsfamily, Rhincodontidae (called Rhinodontes before 1984), which belongs to the subclassElasmobranchii in the class Chondrichthyes. The species originated about 60 million years ago.

The whale shark is found in tropical and warm oceans and lives in the open sea with a lifespan of about 70 years.^[3] Although whale sharks have very large mouths, as filter feeders they feed mainly, though not exclusively, on plankton, which are microscopic plants and animals. However, the BBC program Planet Earth filmed a whale shark feeding on a school of small fish. The same documentary showed footage of a whale shark timing its arrival to coincide with the mass spawning of fish shoals and feeding on the resultant clouds of eggs and sperm.

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Blue shark

The blue shark (Prionace glauca) is a species of requiem shark, family Carcharhinidae, that inhabits deep waters in the world’s temperate and tropical oceans. Preferring cooler waters,^{[clarification needed]} blue sharks migrate long distances, for example from New England toSouth America.

Although generally lethargic, they can move very quickly. Blue sharks areviviparous and are noted for large litters of 25 to over 100 pups. They feed primarily on small fishand squid, although they can take larger prey. Blue sharks often school segregated by sex and size, and this behavior has led to their nickname “wolves of the sea”.

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Silky shark

The silky shark (Carcharhinus falciformis) is a species of requiem shark, 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 a depth of 50 m (164 ft).

The silky shark has a slender, streamlined body and typically grows to a length of 2.5 m (8 ft 2 in). 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-shapedpectoral fins. It is a deep, metallic bronze-gray above and white below.More info here…

Oceanic whitetip shark

The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark inhabiting tropical and warm temperate seas. Its stocky body is most notable for its long, white-tipped, rounded fins.

This aggressive but slow-moving fish dominates feeding frenzies, and is a danger to shipwreck or air crash survivors.^[1] Recent studies show steeply declining populations because its large fins are highly valued as the chief ingredient of shark fin soup and, as with other shark species, the whitetip faces mounting fishing pressure throughout its range.

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Great hammerhead shark

The great hammerhead (Sphyrna mokarran) is the largest species of hammerhead shark, family Sphyrnidae, attaining a maximum length of 6.1 m (20 ft). It is found in tropical and warm temperate waters worldwide, inhabiting coastal areas and the continental shelf.

The great hammerhead can be distinguished from other hammerheads by the shape of its “hammer” (called the “cephalofoil”), which is wide with an almost straight front margin, and by its tall, sickle-shaped first dorsal fin. A solitary, strong-swimming apex predator, the great hammerhead feeds on a wide variety of prey ranging from crustaceans and cephalopods, to bony fishes, to smaller sharks. Observations of this species in the wild suggest that the cephalofoil functions to immobilize stingrays, a favored prey. This species has a viviparous mode of reproduction, bearing litters of up to 55 pups every two years.

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Shortfin mako shark

The shortfin mako shark, Isurus oxyrinchus (“sharp nose”), is a large mackerel shark. Along with the closely related longfin mako (Isurus paucus) it is commonly referred to as a “mako shark“.

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Bronze whaler shark

Bronze whaler sharks, Carcharhinus brachyurus (Günther, 1870), aka narrowtooth shark, bronze, copper shark and bronzys, reach a maximum of 3.25 m in length and weigh a maximum of 305 kg.

They are large sharks with blunt, broad snouts, narrow bent cusps on the upper teeth, and no interdorsal ridges. They are gray to bronze in color on the dorsal side, white on the ventral side.

The fins have similar coloring with the exception of the pelvic fins, which have dusky tips, and the pectoral fins, which have dusky to black tips.More info here…

Leopard shark (Zebra shark)

Stegostoma fasciatum

Description

Zebra sharks get their name from their juvenile appearance: dark bodies with yellowish stipes. As they become adults their coloring changes to a light tan with small dark spots. This adult appearance leads to them often being mistakenly called Leopard sharks. The Zebra shark has a distinctive long tail that is almost as long as the body and prominent ridges that run the length of the body.More info here…

Scalloped hammerhead shark

Sphyrna lewini

Biology

Scalloped Hammerhead Sharks (Sphyrna lewini) are probably the most commonly found species of hammerheads located in coastal regions, appearing in very shallow waters such as estuaries and inlets. Their distribution in the water reaches from the surface down to a depth of approx. 275 m. The young, however, remain mostly in shallow waters along the shore to avoid the danger of falling into the mouths of predators. At certain times of the year and places, and during certain phases of their lives, scalloped hammerheads form very large schools, sometimes counting hundreds of individuals, but they also swim the oceans alone. Some populations remain stationary, others clearly wander, migrating in the direction of the poles in summer. Some sexually-related migrations have also been observed, e.g. females who undertake migrations during particular periods of their sexual development.More info here…

Bull shark

Carcharhinus Leucas

Sharp nose, plain grey dorsal fin (back fin), pectoral fins (side fins), tail and smaller fins, thick bodied
Large; largest around 3.4 metres long
Found on deeper reefs, shallow estuaries, river mouths in cloudy water
Feed on many species including other sharks, dolphins, rays, reef and midwater fish such as walu, tuna, snappers, jacks and tuna, seabirds
Give birth to 1 to 13 live babies, often many kilometres up river
The only shark to be found in completely fresh water

More info here…

Tiger shark

Galeocerdo cuvier

Fijian: Qio Taika/ Qio Oria

ral fins (side fins), tail and smaller fins, thick bodied. Younger sharks show dark grey bars on sides
Very large; largest around 6 metres long, unconfirmed sightings up to 9 metres.
Found in deeper ocean and steep reef areas
Spend days in deeper water
Feeds at night in shallower water on many species, Has been seen to consume other sharks, dolphins, seals, turtles, sea snakes, rays, fish, seabirds, dead and live land animals, and even non-edible items such as metal, wood, and plastic.
Give birth to 10 to 80+ live babies

More info here…

Silvertip shark

Simple ID points:

Sharp nose, white tips to dorsal fin (back fin), pectoral fins (side fins), tail and smaller fins
Large; largest around 3 metres long
Found in deep water inshore and offshore, often seen in deeper reef passages
Feed on midwater and bottom fish, tuna, wahoo, eagle rays, octopus
Give birth to 1 to 11 live babies

More info here…

Sickle-fin lemon shark

A large elongated shark that can reach lengths of up to 3 meters, Sicklefin Lemons are identified by their tan color (hence the name), two rather large and nearly equal sickle-shaped dorsal fins, sickle-shaped pectoral fins, small eyes and a distinctive black spot on the tip of their snout. On Shark Reef, they are frequently confused with the Tawny Nurse Sharks from which they however differ by their continuously open, tooth-studded mouth and by having a proper “sharky” tail.

Like the Silvertips with whom they share an undeserved bad reputation, Lemons appear completely unfazed by divers which they will approach closely.

The best time to encounter Lemon Sharks is between October and December in Fiji.More info here…

Tawny nurse shark

The tawny nurse shark (Nebrius ferrugineus) is a species of carpet shark in the family Ginglymostomatidae, and the only extant member of the genus Nebrius. It is found widely along coastlines in the Indian and Pacific Oceans, preferring reefs,sandy flats, and seagrass beds from very shallow water to a depth of 70 m (230 ft). With a cylindrical body and a broad, flattened head, the tawny nurse shark is quite similar in appearance to the nurse shark (Ginglymostoma cirratum) of theAmericas, from which it can be distinguished by its pointed-tipped dorsal fins and narrow, sickle-shaped pectoral fins. The maximum recorded length is 3.2 m (10.5 ft).More info here…

Blacktip reef shark

The Blacktips are small sharks that hunt fish in very shallow water and are thus rarely encountered by divers. The juveniles however often aggregate in mere centimeters of water within sandy lagoons and are thus frequently encountered by swimmers, snorkelers and beachcombers who spot the black tips of their dorsal fins sticking out of the water.

This is a beautiful small shark of about 1.5 meters in length that can be easily identified by the brilliant black tips with a bright white highlight on both dorsal fins, black tips on the lower lobe of its tail and the anal fin and its tan color with a striking white dash extending from the tail into its flanks.More info here…

Whitetip reef shark

The whitetip reef shark (Triaenodon obesus) is a species of requiem shark, family Carcharhinidae, and the only member of its genus. A small shark usually not exceeding 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 (26–130 ft).

Simple identification points:

Rounded nose, white tip on dorsal fin (back fin) and tail fin
Small; largest around 2 metres long
Found on or near shallow coral reefs
In daytime rests on sandy slopes and caves, sitting motionless
At night feed on crabs, lobster, octopus and fish sleeping in holes in the reef
Give birth to 1 – 5 live babies
Stay within a few kilometers of their home range

More info here…

Grey reef shark

The grey reef shark (Carcharhinus amblyrhynchos, sometimes misspelled amblyrhynchus or amblyrhinchos)^[2] is a species of requiem shark, 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. The grey reef shark has the typical “reef shark” shape, with a broad, round snout and large eyes. This species 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 1.9 m (6.2 ft) long.More info here…