Guide to Shark Identification
Order Hexanchiformes —
Cow & Frilled Sharks
The cow and frilled sharks are generally deep-sea inhabitants. One species, the Broadnose Sevengill Shark (Notorynchus cepedianus) typically inhabits shallow coastal waters, but is only rarely encountered by divers. All hexanchoids share the following characteristics:
- six or seven pairs of gill slits
single dorsal fin, located far posterior on the body- anal fin present
- caudal fin only slightly elevated above axis of body and with a weakly developed lower lobe
- large, teardrop-shaped eyes
Family Hexanchidae — Cow Sharks
Since only one species of cow shark is encountered by divers on a regular basis, for our purposes here, characteristics of the family Hexanchidae can be considered the same as those for the hexanchoid order.
Bluntnose Sixgill Shark (Hexanchus griseus)
What to Look For:
- six pairs of gill slits
- short, blunt snout
- lateral line pale and conspicuous, with odd ‘bump’ at base of caudal fin
- large size
- most often encountered by divers off British Columbia, Canada, during late summer and autumn
Size: average length 8 to 12 feet (2.4 to 3.7 metres); maximum 16 feet (4.8 metres)
Habitat: Intertidal, Rocky Reefs, Coral Reefs (one report), Deep Sea
Distribution: Arctic, Central Pacific, Temperate Eastern Pacific, Tropical Eastern Pacific, Chilean, South Atlantic, Argentinean, Amazonian, Caribbean, Western North Atlantic, Eastern North Atlantic/Mediterranean, West African, Southern African, Madagascaran, Southeast Asian, Western Australian, Northern Australian, Japanese
