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

Identification

  • 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

Distribution

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

Habitat

Diet

Molluscs

Crustaceans

Agnathans

Teleost

Chondrichthyans

Marine Mammals

Feeding Behavior

Predators

Ecological Competitors

Sensory Biology

These data suggest that:

Reproduction

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:

Bibligraphy

Backus, R.H. 1957. Notes on Western North Atlantic Sharks. Copeia, 1957(3): 246-248.

Barans-Charles, A., and F. Ulrich-Glenn. 1995. Sixgill Shark, Hexanchus griseus, Aggressive Feeding Behavior on Epibenthic Crabs. J. Elisha Mitchell Sci. Soc., 110(1): 49-52.

Bass, A.J., J.D. D’Aubrey, and N. Kistnasamy. 1975. Sharks of the East Coast of Southern Africa. V. The Families Hexanchidae, Chlamydoselachidae, Heterodontidae, Pristiophoridae and Squatinidae. Oceanogr. Res. Inst. Invest. Rep. 43: 8-9.

Bauchot, Roland, Roland Platel, Jean-Marc Ridet, Monique Diagne, and Cristian Delfini. 1995. Encéphalisation et Adaptations Ecobiologiques ches les Chondrichthyens. Cybium, 19(2): 153-165.

Bigelow, Henry B., and William C. Schroeder. 1948. Fishes of the Western North Atlantic, Part One: Lancelets, Cyclostomes, Sharks. Sears Foundation for Marine Research, New Haven. pp 80-87.

Branstetter, Steven, and John D. McEachran. 1986. A First Record of Odontaspis noronhai (Lamniformes: Odontaspididae) for the Western North Atlantic, with Notes on Two Uncommon Sharks from the Gulf of Mexico. Northeast Gulf Sci., 8(2): 153-160.

Cadenat, J., and J. Blanche. 1981. Requins de Méditerranée et d’ Atlantique (Plus Particuliérement de la Côte Occidentale d’ Afrique). Faune Tropicale XXI. ORSTROM, Paris. pp 20-22.

Carey, Francis G., and Eugenie Clark. 1995. Depth Telemetry From the Sixgill Shark, Hexanchus griseus, at Bermuda. Envir. Biol. Fishes, 42: 7-14.

Castro, José I. 1983. The Sharks of North American Waters. Texas A&M University Press, College Station. p 37.

Clark, Eugenie, and Emory Kristof. 1986. Sharks at 2,000 Feet. Nat. Geogr., 170(5) [November 1986]: 680-691.

Clark, E., and E. Kristof. 1990. Deep Sea Elasmobranchs Observed From Submersibles in Grand Cayman, Bermuda, and Bahamas. NOAA Tech. Rep. NMFS 90: 275-290.

Clark, Eugenie, and Emory Kristof. 1991. How Deep Do Sharks Go? Reflections on Deep Sea Sharks. Bull. Amer. Litt. Soc, 19(4)/20(1): 79-84.

Clemens, W.A., and G.V. Wilby. 1946. Fishes of the Pacific Coast of Canada. Bull. Fish. Res. Bd. Can., 68: 52.

Coad, Brian W. 1995. Encyclopedia of Canadian Fishes. Canadian Museum of Nature, Ottawa. pp 686-687.

Cohen, J. 1985. The Visual System of the Sixgill Shark, Hexanchus griseus. ASIH/AES Abstracts, University of Tennessee, Knoxville.

Compagno, Leonard J.V. 1984. Sharks of the World. FAO Species Catalogue, Vol. 4, Part 1 (Hexanchiformes to Lamniformes). United Nations Development Programme, Rome. pp 19-20.

Costa, M.E., and T.C. Borges. 1998. Shark Discard from the Southern Portuguese Coastal Fisheries. ICES, 15: 1-20.

Crow, Gerald L., Christopher G. Lowe, and Bradley M. Wetherbee. 1996. Shark Records from Longline Fishing Program in Hawai’i with Comments on Pacific Ocean Distributions. Pac. Sci., 50(4): 382-392.

Ebert, David A. 1986. Aspects on the Biology of Hexanchid Sharks along the California Coast. pp 437-449 In T. Uyeno, R. Arai, T. Taniuchi, and K. Matsuura (eds.) Indo-Pacific Fish Biology: Proceedings of the Second International Conference on Indo-Pacific Fishes. Ichthyological Society of Japan, Tokyo.

Ebert, David A. 1986. Biological Aspects of the Sixgill Shark, Hexanchus griseus. Copeia, 1986(1): 131-135.

Ebert, David A. 1994. Diet of the Sixgill Shark Hexanchus griseus off Southern Africa. S. Afr. J. Mar. Sci., 14: 213-218.

Faughnan, Victor R. 1980. The National Shark-O-Pedia. Undersea Resources, Honolulu. pp 47-48.

Hart, J.L. 1973. Pacific Fishes of Canada. Fish. Res. Bd. Can. Bull. 180: 27-28.

Herald, Earl S. 1968. Size and Aggressiveness of the Sevengill Shark (Notorynchus maculatus). Copeia, 1968(2): 412-414.

Issacs, John D., and Richard A. Schwartzlose. 1975. Active Animals of the Deep-Sea Floor. Sci. Amer., 233(4) [October 1975]: 85-91.

Kabasakal, H. 1998. The First Record of the Bluntnose Six-Gill Shark [Hexanchus griseus (Bonnaterre, 1788]) in the Sea of marmara. Acta Adriat., 39(1): 67-70.

Kato, Susumu, Stuart Springer, and Mary H. Wagner. 1967. Field Guide to Eastern Pacific and Hawaiian Sharks. US Fish and Wildlife Service, Circular 271. pp 5-6.

Kemp. Noel R. 1978. Detailed Comparisons of the Dentitions of Extant Hexanchid Sharks and Tertiary Hexanchid Teeth from South Australia and Victoria (Selachii: Hexanchidae). Mem. Nat. Mus. Vict., 39: 61-83.

Last, Peter R., and John D. Stevens. 1994. Sharks and Rays of Australia. CSIRO Australia. pp 40-41.

Lineaweaver, Thomas H., III, and Richard H. Backus. 1970. The Natural History of Sharks. J.B. Lippincott Co., Philadelphia. pp 168-170.

Lynch, D.D. 1963. First Australian Record of Hexanchus griseus (Bonnaterre) 1780. The Six-Gilled Shark. Mem. Nat. Mus. Vict., 26: 259-261.

Marliave, Jeff. 1984. Six Gill Shark: a Primeval Visitor From the Abyss. Skin Diver, 33(9) [September 1984]: 40-41.

Martin, R.  1991.  Sixgill Non Sequitur.  DIVER Magazine, Sept. 1991: 45-46.

Martin, R. 1998.  Swimming With Jurassic Shark.  Scuba Diver, November-December 1998: 66-68.

Mayhew, Anne.  1988.  Diving For Deep Teeth.  Beautiful British Columbia, 30(2) [Summer 1988]: 18-23.

Michael, Scott W.  1993.  Reef  Sharks and Rays of the World.  Sea Challengers, Monterey.  p 34.

Miller, Bruce, and David W. Greenfield.  1965.  A Juvenile Six-Gilled Shark (Hexanchus griseus) from the San Juan Islands, Washington.  J. Fish. Res. Bd. Canada, 22(3): 857-859.

Nevell, Len.  1998.  Bluntnose Six-Gilled Shark.  Glaucus, 9(1): 28-29

O’Donoghue, C.H., and L.L. Bolton.  1926.  Note on the Structure of the Lymphoid Organ (Organ of Leydig) and Spleen of Hexanchus corinus.  J. Anat., 61: 40-63.

O’Neil, Grady.  1995.  A Summary of Data Collected During Tagging Cruises For the Sixgill Shark (Hexanchus griseus), May, June, July, and September 1994.  Unpubl. Rep., Dir. Res. (Biol 490) U. of Victoria, Victoria.  48 pp.

Roedel, Phil M., and Wm. Ellis Ripley.  1960.  California Sharks and Rays.  Calif. Dept. Nat. Res. Div. Fish & Game, Fish Bull. No. 75.  p 40.

Springer, Stewart, and Richard A. Waller.  1969.  Hexanchus vitulus, a New Sixgill Shark from the Bahamas.  Bull. Mar. Sci., 19(1): 159-174.

Steel, Rodney.  1985.  Sharks of the World.  Facts on File, New York.  pp 81-83.

Stefanescu, C., D. Lloris, and J. Rucabado.  1992.  Deep-Living Demersal Fishes in the Catalan Sea (Western Mediterranean) Below a Depth of 1000 m.  J. Nat. Hist., 26: 197-213.

Taylor, Leighton.  1993.  Sharks of Hawai’i:  Their Biology and Cultural Significance.  University of Hawaii Press, Honolulu.  p 50.

Tortonese, Enrico.  1985.  Gli Squali Mediterranei del Genere Hexanchus.  Atti. Soc. Ital. Sci. Nat. Museo Civ. Stor. Nat. Milano, 126(3-4): 137-140.

Wallet, Tim.  1983.  Shark Attack and Treatment of Victims in Southern African  Waters.  C. Struik Publishers, Capetown.  pp 121-122.

Went, A.E.J.  1979.  Two Elasmobranchs Scarce in Irish Waters.  Ir. Nat. J., 19(11): 381-383.

Wheeler, Alwyne.  1969.  The Fishes of the British Isles and North-West Europe.  Macmillan, London. 
p 38-39.

Zama, A.  1988.  Southern Distribution of the Sixgill Shark Hexanchus griseus (Bonnaterre, 1788) and the Striped Mullet Mugil cephalus Linnaeus, 1758 in Chile.  Cienc. Technol. Mar. Valparaiso, 12: 137-140.

 

 

ReefQuest Centre for Shark Research
Text and illustrations © R. Aidan Martin
Copyright | Privacy