Sharpnose Sevengill Shark, Heptranchias perlo (Bonnaterre 1788)
A male Sharpnose Sevengill Shark, Heptranchias perlo, photographed on the Tongue of the Ocean, Bahamas, depth 718 m. Source: Fig. 3, in Phillips et al. (2019) First in situ observations of the sharpnose sevengill shark (Heptranchias perlo), from the Tongue of the Ocean, Bahamas. Journal of the Ocean Science Foundation 32: 17–22.. License: CC by Attribution
A wide-ranging, uncommon shark with the following identifying features:
Sharpnose Sevengill Shark, Heptranchias perlo (Bonnaterre 1788)
More Info
Distribution |
Cairns, Queensland, around southern Australia, to north of Darwin, Northern Territory. Usually on the continental shelf and upper slope at depths to 1000 m, although also found inshore. Elsewhere the species is widespread in tropical and temperate waters of the Atlantic, Indian and margins of the Pacific Ocean; usually near the bottom in depths to 1000 m, mostly at 300-600 m.
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Features |
Vertebrae 143-161 (precaudal 89-95) Body elongate, shallow (body depth about 11% TL); no keels or precaudal pits on caudal peduncle. Head moderately large (approx. 17% TL), narrow; snout tapering, length more than 1.5 times internasal distance; nostrils not connected to mouth by groove; eyes oval; spiracles minute; teeth in upper jaw fang-like, with slender oblique cusp, those laterally with one or two smaller cusps on either side of base, teeth in lower jaw comb-like with six to ten cusps, second distinctly longer than others, distinctive median tooth in lower jaw only, rear teeth in both jaws rudimentary; seven gill slits in front of pectoral fin. Single dorsal fin near tail, above region between ventral and anal fins; anal fin small, height about half height of dorsal fin; caudal fin heterocercal, upper lobe long (approx. 30% TL), with distinct sub- terminal notch, lower lobe short. Pectoral fins moderately small, broad, tip narrowly rounded, hind margin weakly concave. |
Size |
Reaches 140 cm TL. |
Colour |
Brownish-grey above, paler below; margins of pectoral, dorsal and upper caudal fins white in adults; juveniles with dark tips to dorsal and upper caudal-fin, and dark blotches on lower sides; fluorescent green when fresh. |
Feeding |
Carnivore - feeds mostly on squid, bony fishes and crustaceans. |
Biology |
Matures at 75 to 85 cm TL (males), 90 to 105 cm TL (females). The species is aplacental viviparous (ovoviviparous) - the young develop in eggs that hatch and inside the mother before they are born. Females produce litters of 6-20 pups, about 25 cm TL at birth. |
Fisheries |
Although not targeted, the species is taken as bycatch in deepwater fisheries throughout its range. Flesh reportedly good eating. |
Species Citation |
Squalus perlo Bonnaterre 1788, Tableau Encyclopédique et Méthodique des trois Règnes de la Nature. Ichthyologie: 10. Type locality: Mediterranean Sea. |
Resources |
Sharpnose Sevengill Shark, Heptranchias perlo (Bonnaterre 1788)
References
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Bass, A.J., A'ubrey, J.D. & Kistnasamy, N. 1975. Sharks of the east coast of southern Africa. V. The families Hexanchidae, Chlamydoselachidae, Heterodontidae, Pristiophoridae and Squatinidae. South African Association for Marine Biological Research, Oceanographic Research Institute Investigational Report No. 43.
Bonnaterre, J.P. 1788. Tableau Encyclopédique et Méthodique des trois Règnes de la Nature. Ichthyologie. Paris. pp. 1-215, 102 pls
Capapé, C. 1980. New description of Heptranchias perlo (Bonnaterre 1788) (Pisces, Pleurotremata, Hexanchidae). Biological reproduction data and diets of some samples of the Tunisia Coasts. Bull. Off. Natl. Peches (Tunisia) 4(2): 231–264.
Compagno, L.J.V. 1984. FAO Species Catalogue. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Hexanchiformes to Lamniformes. FAO Fisheries Synopsis No. 125. Rome : FAO Vol. 4(1) pp. 1-249.
Compagno, L.J.V., Dando, M. & Fowler, S. 2005. A Field Guide to the Sharks of the World. London : Collins 368 pp.
Compagno, L.J.V. & Niem, V.H. 1998. Hexanchidae, Echinorhinidae, Squalidae. pp. 1208-1232 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 2 687-1396 pp.
Garman, S. 1913. The Plagiostomia (sharks, skates and rays). Memoirs of the Museum of Comparative Zoology, Harvard University 36: 1-528 pls 1-77
Garrick, J.A.F. & Paul, L.J. 1971. Heptranchias dakini Whitley, 1931, a synonym of H. perlo (Bonnaterre, 1788), the sharpnosed sevengill or perlon shark, with notes on sexual dimorphism in this species. Zoology Publications from Victoria University of Wellington (New Zealand) 54: 1–14.
Kemp, N.R. 1978. Detailed comparisons of the dentitions of extant hexanchid sharks and tertiary hexanchid teeth from South Australia and Victoria, Australia (Selachii : Hexanchidae). Memoirs of the National Museum of Victoria, Melbourne 39: 61-83 figs 1-5 pls 12-15
Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs.
Last, P.R. & Stevens, J.D. 1994. Sharks and Rays of Australia. Canberra : CSIRO Australia 513 pp. 84 pls.
Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia 2, 550 pp.
Macbeth, W.G., Vandenberg, M. & Graham, K.J. 2008. Identifying Sharks and Rays; a Guide for Commercial Fishers. Sydney : New South Wales Department of Primary Industry 71 pp.
McCulloch, A.R. 1911. Report on the fishes obtained by the F.I.S. Endeavour on the coasts of New South Wales, Victoria, South Australia and Tasmania. Part 1. Zoological (Biological) Results. Endeavour 1(1): 1-87 figs 1-20 pls 1-16
Paul, L. & Fowler, S. (SSG Australia & Oceania Regional Workshop, March 2003) 2003. Heptranchias perlo. The IUCN Red List of Threatened Species 2003: e.T41823A10572878. http://dx.doi.org/10.2305/IUCN.UK.2003.RLTS.T41823A10572878.en. Downloaded on 03 February 2019.
Phillips, B.T., Shipley, O.N., Halvorson, J., Sternlicht, J.K. & Gallagher, A.J. 2019. First in situ observations of the sharpnose sevengill shark (Heptranchias perlo), from the Tongue of the Ocean, Bahamas. Journal of the Ocean Science Foundation 32: 17-22. https://doi.org/10.5281/zenodo.2539708 Open access
Stead, D.G. 1963. Sharks and Rays of Australian Seas. Sydney : Angus & Robertson 211 pp. 63 figs.
Stewart, A.L. 2002. At sixes and sevens with four cowsharks. Seafood New Zealand 10(7): 65–68.
Stewart, A.L. 2015 21 Family Hexanchidae, pp. 115-118 in Roberts, C.D., Stewart, A.L. & Struthers, C.D. (eds) The Fishes of New Zealand. Wellington : Te Papa Press Vol. 2 pp. 1-576.
Tanaka, S. & Mizue, K. 1977. Studies on sharks. 11. Reproduction in female Heptranchias perlo. Bulletin of the Faculty of Fisheries Nagasaki University No. 42: 1–9.
White, W. 2008. Shark Families Heterodontidae to Pristiophoridae. pp. 32-100 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.
Whitley, G.P. 1931. New names for Australian fishes. The Australian Zoologist 6(4): 310-334 1 fig. pls 25-27 (as Heptranchias dakini)
Whitley, G.P. 1940. The Fishes of Australia. Part 1. The sharks, rays, devil-fish, and other primitive fishes of Australia and New Zealand. Sydney : Roy. Zool. Soc. N.S.W. 280 pp. 303 figs.(as Heptranchias dakini)