Biology of the Bluntnose Sixgill

Adapted from a PowerPoint presentation given by R. Aidan Martin at a Sixgill Shark conference held at the Vancouver Aquarium, Vancouver, Canada, in November 2000


  • heavy body
  • single dorsal fin, located far posterior on body
  • anal fin present
  • caudal fin only slightly elevated above axis of body and with a weakly developed lower lobe
  • six pairs of gill slits
  • short, blunt snout
  • broadly arcuate mouth
  • six series of broad, comb-shaped teeth on each side of lower jaw
  • large, teardrop-shaped eyes
  • lateral line pale and conspicuous, with an odd ‘bump’ at base of the caudal fin
  • caudal peduncle short and stout, distance from rear of dorsal fin to upper caudal fin origin about equal to length of dorsal fin base
  • large size, averaging 8-12 feet (2.4 to 3.7 metres) long
  • one of only 11 sharks that regularly exceed 13 feet (4 metres) in length


The Bluntnose Sixgill may be the most widely distributed of all sharks, rivalled only by the White Shark (Carcharodon carcharias)








Marine Mammals

Feeding Behavior


Ecological Competitors

Sensory Biology

These data suggest that:


Social Behavior

As in other hexanchoids (but not chlamydoselachoids!) strong sexual dimorphism in teeth – male has more erect primary cusps than female, especially noticeable on anteriormost cusp of enlarged lower anterior teeth of male, which is about 50% longer than the secondary cusp that follows it

So What Are They Doing in Shallow Water?

My hypothesis:


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