Broadnose Sevengill Shark
Notorynchus cepedianus

Physical Description

• A medium-sized shark, it can be up to 10 feet long.
• It has seven gills on each side, as its name suggests (most sharks only have 5).
• Its back and sides are silvery-gray, reddish brown, or olive brown in coloration, with small black spots; undersides are whitish in coloration.
• It has a wide head with small eyes and a blunt nose.
• It only has one dorsal (back) fin, while most sharks have two.

Range

• Found in all oceans with the exception of the North Atlantic and the Mediterranean.
• Atlantic: from southern Brazil to northern Argentina; Namibia to South Africa.
• Pacific: Japan to New Zealand and Australia; British Columbia to Chile.
• May be found off of India as well.

Habitat

• Found in the open ocean.
• Prefers shallow, inshore waters.
• Use bays and estuaries as nurseries for their pups.

Reproduction

• Like all cow sharks, sevengills’ embryos develop inside egg casings inside the mother.
• The mother then gives birth to live young, up to 82-95 pups per litter.
• Gestation lasts 12 months.
• Female sevengills move into shallow bays to give birth in the late spring and early summer.
• The young pups are 15-17 inches when they are born and they stay in the shallow water for the first few years of their life before moving into deeper waters.

Diet

• Other sharks, bat rays, harbor seals, crabs, carrion, octopuses, bony fishes.
• They will hunt in packs for seals.

Predators

• White sharks, large predatory sharks, even other broadnose sevengill sharks.

Interesting Facts

• The bottom teeth of a sevengill are comb-shaped, and are used for anchoring into their prey; their upper teeth are sharp and jagged and are used for sawing off pieces of their prey.
• Sevengill sharks can go days or weeks without eating. They may eat as little as 6% of their body weight per month! 

Sources: Monterey Bay Aquarium; Florida Museum; MarineBio.org

Photo: Howard Hill