NOVA Online | Island of the Sharks

Order

Family

Species

Lamniformes
Mackerel Sharks
Most mackerel sharks have long snouts and mouths that stretch behind the eyes. They also feature two dorsal fins and an anal fin. These species range from intertidal areas to open ocean at depths of nearly 4,000 ft. Embryos of these sharks dine on their younger siblings and fertilized eggs in the womb.

ODONTASPIDIDAE
Sand Tiger Sharks
Appearance: Large, heavy-bodied sharks with fairly long, flattened or conical, pointed snouts, small to fairly large eyes, protrusible jaws with large, slender-cusped teeth. The gill openings are short and there are precaudal pits but no lateral caudal keels.

Carcharias taurus
Sand tiger or Grey nurse shark

Size: All species are large and reach a maximum size of 12 ft.

Habitat: These sharks are associated with continental or insular landmasses; none is oceanic. They reach depths of 630 to nearly 4,000 ft.

Distribution: Found in all warm temperature and tropical seas, though distribution of individual species may be patchy.

Diet: Bony fishes, small sharks and rays, cephalopods, and large crustaceans.

Shark bite: The sand tiger shark is denser than water but it swallows airs at the surface and holds it in its stomach to maintain approximately neutral buoyancy.

Four species

PSEUDOCARCHARIIDAE
Crocodile Sharks
Appearance: Named for its prominent, narrow-cusped teeth, the crocodile shark is a small, spindle-shaped oceanic shark with huge eyes, a long, conical snout, protrusible jaws and fairly long gill openings. It has precaudal pits, low lateral caudal keels, and a short asymmetrical caudal fin with a moderately long ventral lobe.

Pseudocarcharias kamoharai
Crocodile Shark

Size: Maximum length is about 3.5 ft.

Habitat: Mainly in the open ocean and continental waters.

Distribution: A spotty distribution in the eastern Atlantic, western Indian Ocean, western north Pacific, and the eastern and central Pacific.

Diet: Midwater bony fishes, squid, and crustaceans.

Shark bite: The large eyes of the crocodile shark suggest nocturnal or deepwater activity, and possibly a habit of moving toward the surface at night and away from it in the day.

One species

MITSUKURINIDAE
Goblin Sharks
Appearance: The goblin shark has a long, flat, daggerlike snout, tiny eyes, a soft flabby body, long protrusible jaws with large, slender, needlelike teeth, and a long low caudal fin without a ventral lobe or precaudal pits.

Mitsukurina owstoni
Goblin shark

Size: Reaches a length of almost 12 ft.

Habitat: This bottom-dwelling shark occurs mainly on the continental shelves and outer slopes in depths down to at least 2,400 ft. Sometimes it is found close inshore.

Distribution: Spans most oceans, including the western and eastern Atlantic and the western Pacific.

Diet: Probably includes small, soft-bodied prey including fishes, shrimps, and squids.

Shark bite: The largest goblin shark ever caught weighed 466 pounds.

One species

MEGACHASMIDAE
Megamouth Sharks
Appearance: A large, heavy-bodied, flabby, cylindrical oceanic shark with small eyes, short, bluntly rounded snout, huge mouth, and protrusible jaws with very small but numerous hook-shaped teeth. It has short gill openings, precaudal pits but no caudal keels, and a long asymmetrical caudal fin with a moderately long ventral lobe.

Megachasma pelagios
Megamouth shark

Size: About 15 ft long.

Habitat: At least ten have been found, in the open ocean and over the upper continental slope.

Distribution: The central and eastern Pacific.

Diet: A filter-feeder of small euphausiid shrimps, copepods, and pelagic jellyfish.

Shark bite: The megamouth shark has over 100 rows of shiny teeth which may attract the plankton, jellyfish, and squid that it sieves from deep waters.

One species

Family

Species

ALOPIIDAE
Thresher Sharks
Appearance: Large, stout-bodied, cylindrical sharks with moderately large to huge eyes, short conical snouts, small mouths with slightly protrusible jaws, and small bladelike teeth. They have short gill openings, precaudal pits but no caudal keels. Their gigantic scythe-shaped caudal fins are about as long as the rest of the shark.

Alopias pelagicus
Pelagic thresher shark<

Size: Maximum length about 20 ft.

Habitat: In oceanic and coastal waters, and near the bottom down to at least 1,650 ft.

Distribution: All temperate and tropical seas.

Diet: Small pelagic and bottom schooling fishes and squid, octopuses, and crustaceans.

Shark bite: Thresher sharks use their tail fins to stun and frighten fish into a group so that they can be fed upon more easily (this is called "threshing").

Three species

CETORHINIDAE
Basking Sharks
Appearance: A gigantic, heavy-bodied, spindle-shaped shark with minute eyes, a moderately long hooked or conical snout, a large mouth with only slightly protrusible jaws and minute hooked teeth. It has enormous gill openings that virtually encircle the head.

Cetorhinus maximus
Basking shark

Size: Second only to the whale shark in size. Individuals of between 40 and 50 ft have been reported, but most do no exceed 32 ft.

Habitat: Most abundant in cold temperate coastal continental waters. In shelf waters they occur well offshore but range right up to the surf-line and into enclosed bays.

Distribution: The north and south Atlantic and the north and the south Pacific.

Diet: A filter-feeder that traps minute planktonic crustaceans, principally copepods, on rows of unique gill-raker denticles.

Shark bite: Most of the basking sharks that have been caught are female (30 females caught to every one male), which indicates a possible separation of the sexes, either by time or location.

One species

LAMNIDAE
Mackerel Sharks
Appearance: Large, heavy-bodied, spindle-shaped sharks with small to moderately large eyes, long conical snouts, large mouths and only slightly protrusible jaws with large, bladelike teeth. The large gill openings do not encircle the head.

Carcharodon carcharias
Great white shark

Size: The great white, the largest species in this family, reaches a maximum length of about 20 ft.

Habitat: Oceanic and coastal waters, from the surface, intertidal, surfline and enclosed bays down to depths of 4,200 ft.

Distribution: Found in all cold temperature tropical seas.

Diet: Small to large bony fishes, squid, other sharks and, in the case of the great whites, sea turtles, seabirds, seals, sea lions, porpoises, and carrion, including dead whales and other mammals.

Shark bite: Mako shark fetuses are intra-uteral cannibals: they consume their less developed siblings.

Five species