NOVA Online | Island of the Sharks

Order

Family

Species

Hexanchiformes
Sixgill, Sevengill and Frilled Sharks
These sharks sport a single dorsal fin, six or seven pairs of gill openings and an anal fin. They occur in deep water throughout the world's oceans and hatch young from eggs inside the body.

CHLAMYDOSELA
Frilled Sharks
Appearance: Resembling an eel, this slim shark has a snake-like head and a terminal mouth, small teeth in both jaws, and six pairs of gill openings with frilly margins.

Chlamydoselachus anguineus
Frilled Shark

Size: Up to 78.4 in

Habitat: On or near the bottom on outer continental and island shelves and upper slopes at depths between about 400 and 4,200 feet, but occasionally inshore or at the surface.

Distribution: Scattered marine locations worldwide.

Diet: Very little is known, but the remains of a small shark were found in a frilled shark in South Africa.

Shark bite: Frilled sharks reproduce all year round in deep water off Japan.

One Species

HEXANCHIDAE
Sixgill and Sevengill Sharks
Appearance: Big-bodied sharks with high fins and lengthy snouts. Their upper teeth are ideal for impaling prey, while their lower cusps are designed for cutting. Six pair of gill openings in two species, seven in two other species.

Hexanchus griseus
Bluntnose sixgill shark

Size: The smallest of the group is the sharpnose sevengill shark, which does not exceed 4.5 ft. The largest of the group is the giant bluntnose sixgill shark, which grows to almost 16.5 ft.

Habitat: The two sixgills and the sharpnose sevengill occur mostly in deeper water on outer shelves and upper slopes from about 300 to 6,000 feet. The spotted sevengill favors continental shelves and breeds in shallow bays.

Distribution: Wide-ranging in coastal and offshore waters of temperate and tropical seas. None is oceanic.

Diet: Relatively large prey, such as bony fishes, other sharks, rays, chimaeras, squid, crabs, shrimp, and carrion. The bluntnose sixgill and broadnose seven grill feed on all kinds of carrion as well as live prey.

Shark bite: The broadnose sevengill shark may coordinate its movements with the tidal cycle, moving in with a tidal rise and out with its fall.

Four Species