Broadnose Sevengill Shark

Threat Level: low

The Broadnose Sevengill Shark is also known as bluntnose sevengill
shark, broad snouted sevengill, broadnose sevengill shark,
broad-snout, cowshark, ground shark, Pacific seven-gill shark,
seven-gill cowshark, sevengill shark, seven-gilled shark,
spotted cow shark, spotted seven-gilled shark,
and Tasmanian tiger shark.

BROADNOSE SEVENGILL SHARK

Scientific Name.... Notorynchus Cepedianus
Family Name...... Hexanchidae

General Information: The broadnose sevengill is a large shark that is easily recognized because of its seven pairs of gill slits ( most sharks have five pairs ). It also has another unusual feature and that it has a single, small dorsal fin. It has a wide head with a short, blunt snout and small eyes.

Size: The Broadnose sevengill are large and powerful sharks, that can grow up to 10 feet long, and the maximum reported weight was 234 pounds.

Teeth: The teeth of the broadnose sevengill sharks are very effective for cutting. The teeth of the upper jaw are jagged with cusps, except for a single middle tooth; the teeth on the bottom jaw are comb-shaped.

Color: The color of a sevengill shark is quite variable, which is an adaption that allows the shark to blend in with its environment. The dorsal color is silver-gray to brownish, allowing the shark to blend in with the dark marine waters. The underside is light in color, which blends the shark in with the surface of the water when viewed from below. This coloration pattern is common among many species of predatory sharks. The body and sides are speckled with numerous small dark and white spots.

Feeding Habits: Broadnose sevengill sharks diet consists of other sharks, seals, bony fishes, carrion, and rays. It bites pieces of flesh from other sharks caught in gill nets and hooks. They sneak up on their prey from behind and quickly dashing at the last moment for the capture. One of these most fascinating behaviours observed involves cooperative hunting by groups of these sharks. In these events the prey, which is usually a cetacean or a large shark and is too big for a single sevengill to handle on its own. Groups of theses sharks will form a loose circle around larger prey species and begin to tighten their formation as the prey animal attempts to escape. Ultimately, one or more sharks will rush in and attack the prey animal and this will elicit group feeding. They are also known to be cannibals.

Social Behaviour: The sevengill sharks sometimes hunt in packs, working as a team to capture large prey such as marine mammals and other sharks.

Habitat | Migration | Distribution: The broadnose sevengill sharks are found in temperate regions of the South Atlantic, Pacific, and Indian Oceans. These sharks prefer to live in temperate waters on continental shelves at depths down to 450 feet. It will often come close inshore in shallow bays and inlets. Sevengill sharks prefer rocky bottom habitats although they commonly occur over sandy and muddy substrates.

Life Span: Life expectancy of this species is about 50 years.

Reproduction: Broadnose sevengill sharks are ovoviviiparity bearing live young. Males mature at about 5 feet and females at about 7 feet. The females move into shallow bays to give birth after a 12 month gestation period. This occurs during the spring and summer months. The litter size vary and can be as large as 82 pups. The pups are about 16-18 inches in length when born.

Swimming: The majority of the broadnose sevengill sharks will swim slowly along the bottom while occasionally cruising to the surface.

Broadnose Sevengill Shark Attacks: There are no records of it attacking people ( except for divers in aquariums ), but it will scavenge on human corpses. It is potentially dangerous. In captivity, it is aggressive when attacked, and it will struggles vigorously to escape when captured.

Population Report: Although this species is wide spread, it is not particularly abundant.