Tags: Taxonomy,  Cow Sharks 

Cow Sharks

Order: Hexanchiformes

Cow sharks are little known because they spend most of their lives in deep, cold oceans beyond the reach of divers. However, there are times during the year when some species spend time in shallow waters to feed and give birth. Cow sharks are unusual in that they have six, and in some species, seven pairs of gills. They have wide heads, small eyes, and a heavily-built body.


Photo Gallery

These shy, deepwater sharks are rarely seen by humans

Characteristics of Cow Sharks

# of Species

Body shape
Rounded, stout body. Species range from 4.5 to 15.5 feet.
Mouth position
Anal fin
Dorsal Fin
1, far to the back of the shark
Fin spines
# of Gill slits
6 or 7
Ovoviviparous (eggs develop in the mother’s body and are born alive). Relatively large litters of up to 80 pups born in shallow bays.
Unique qualities
Extra gills, comb-shaped bottom teeth
Deep, often cold marine exclusively marine, in northern, temperate, and tropical zones of the Atlantic, Pacific, and Indian Oceans
Cow sharks are aggressive predators and eat other sharks, rays, bony fish, seals, and scavenged prey

The 4 Species of Cow Shark


Common name

Heptranchias perlo

Sharpnose Sevengill Shark

Hexanchus griseus

Bluntnose Sixgill Shark

Hexanchus nakamurai

Bigeye Sixgill Shark

Notorynchus cepedianus

Broadnose Sevengill Shark

Red indicates inclusion on the IUCN Red List of Endangered Species.