Porbeagle, Lamna nasus (Bonnaterre 1788)


Other Names: Mackerel Shark

A Porbeagle, Lamna nasus. Source: E. Hoffmayer, S. Iglésias & R. McAuley / NMFS_NOAA. License: Public Domain

Summary:

A large powerful shark with a robust spindle-shaped body, a long conical snout, a crescent-shaped tail. The Porbeagle is dark bluish-grey above, whitish below with a distinct white patch on the rear edge of the first dorsal fin. The species has a short secondary keel on the base of the tail below the large keel on the caudal peduncle, and smooth teeth with small lateral cusps.

Filming and tagging Porbeagle Sharks off the Cornwall coast, NE Atlantic.

Video of a Porbeagle Shark in the North Sea.

A Porbeagle Shark in St. Margaret's Bay, Nova Scotia

The ARKive site has lots of images of Porbeagle sharks.


Cite this page as:
Dianne J. Bray, Lamna nasus in Fishes of Australia, accessed 15 Nov 2018, http://fishesofaustralia.net.au/home/species/1848

Porbeagle, Lamna nasus (Bonnaterre 1788)

More Info


Distribution

Widespread in southern Australia from the Sydney region (New South Wales) to north of Perth (Western Australia), Elsewhere, the species occurs in the North Atlantic, and is circumglobal in the Southern Hemisphere (30–60°S).

Porbeagle sharks undertake daily vertical migrations to feed on mesopelagic fishes and squid. They regularly dive to 600 m with a maximum recorded depth of 1024 m during the day. At night, they spend most of their time at depths of 200–600 m in the open ocean (Francis et al. 2015).

Features

Vertebrae 150-162 (precaudal 84-91); Jaw teeth (upper) 30-31; Jaw teeth (lower) 27-29.

Body robust, spindle-shaped, snout long, pointed; first dorsal fin large, triangular; second dorsal fin small, above the small anal fin; pectoral fins large, positioned behind the long gill slits; caudal fin crescent-shaped with a short second keel below the larger keel on the tail base; teeth moderately large, smooth, blade-like, with small lateral cusps.

Size

  • Maximum length 3.65 m; Maximum weight 350 kg
  • Colour

    Dark bluish-grey to bluish-black above, white below, with a white patch on the trailing edge of the first dorsal fin.

    Feeding

    Carnivore - feed mostly on mesopelagic fishes and squid, foraging in the vertically migrating deep scattering layer. 

    Biology

    Reproduction aplacental viviparous. The developing embryos are first nourished by yolk sac, and then feed on fertilised yolk-filled eggs within the uterus (oophagy). The embryos use special fang-like teeth to open the egg capsules. Litters of up to 5 pups are born after a gestation period of 8-9 months.

    Like other sharks in the family Lamnidae, these active predators are warm-blooded. Porbeagles can maintain their body temperatures 3-8ºC above the temperature of the surrounding water. They have a specialised heat-exchange system that enables them to retain the heat produced by their metabolism. This adaptation enables the Porbeagle to be a fast-swimming predator in cold-temperate waters.

    Fisheries

    The Porbeagle shark meat and fins are in high demand, and the species is heavily fished in parts of its range. Porbeagle sharks are taken both in target fisheries and as bycatch, in longline, gillnet, driftnet, pelagic and bottom trawl fisheries.

    Finning bans are in place for most international waters, and Australian legislation prohibits the possession of shark fins separate from the carcass in longline fisheries.

    Conservation

  • IUCN Red List : Vulnerable (Globally)
  • CITES Listed : Appendix II
  • Porbeagle sharks are threatened by overfishing. They grow slowly, take a long time to mature (8-13 years), and produce few young (1-5 pups per litter) after a long gestation period (8-9 months). The species is protected in parts of its range.

    Remarks

    Although not considered particularly dangerous, rare attacks on humans have been reported.

    Similar Species

    The Porbeagle differs from the White Shark (Carcharodon carcharias) in having smooth, spindle-shaped teeth (vs serrated triangular teeth) and in the second dorsal fin positioned above the anal fin. Unlike the Shortfin Mako (Isurus oxyrinchus), the Porbeagle has small teeth with lateral cusps and a secondary caudal-fin keel.

    Species Citation

    Squalus nasus Bonnaterre, 1788. Tableau Encyclopédique. Ichthyologie: 10, pl. 85(350). Type locality: unknown, probably British waters.

    Author

    Dianne J. Bray

    Porbeagle, Lamna nasus (Bonnaterre 1788)

    References


    Bigelow, H.B. & Schroeder, W.C. 1953. Sawfishes, guitarfishes, skates and rays. pp. 1-514, figs 1-117 in Parr, A.E. (ed.) Fishes of the western North Atlantic. Memoir. Sears Foundation of Marine Research 1(2): 1-599

    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. 2001. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). Rome : FAO, FAO Species Catalogue for Fisheries Purposes No. 1 Vol. 2 269 pp. 

    Compagno, L.J.V., Dando, M. & Fowler, S. 2005. A Field Guide to the Sharks of the World. London : Collins 368 pp.

    Francis, M.P. & Duffy, C. 2005. Length at maturity in three pelagic sharks (Lamna nasus, Isurus oxyrinchus and Prionace glauca) from New Zealand. Fishery Bulletin 103: 489–500.

    Francis, M.P., J.C. Holdsworth & B.A. Block. 2015. Life in the open ocean: seasonal migration and diel diving behaviour of Southern Hemisphere porbeagle sharks (Lamna nasus). Marine Biology 162(11): 2305-2323. Abstract

    Francis, M.P., L.J. Natanson & S.E. Campana. 2008. Porbeagle (Lamna nasus). In E.K. Pikitch & M. Camhi (eds). Sharks of the open ocean. Blackwell Scientific.

    Francis, M.P. & J.D. Stevens. 2000. Reproduction, embryonic development and growth of the porbeagle shark, Lamna nasus, in the South-west Pacific Ocean. Fishery Bulletin 98: 41-63.

    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.

    Pepperell, J. 2010. Fishes of the Open Ocean a Natural History & Illustrated Guide. Sydney : University of New South Wales Press Ltd 266 pp.

    Stevens, J. 2005. Porbeagle shark Lamna nasus. In: S.L. Fowler, R.D. Cavanagh, M. Camhi, G.H. Burgess, G. Cailliet, S.V. Fordham, C.A. Simpfendorfer J.A. Musick (eds). Sharks, rays and chimaeras: the status of the chondrichthyan fishes. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK.

    Stevens, J.D., Dunning, M.C. & Machida, S. 1983. Occurrence of the porbeagle shark Lamna nasus, in the Tasman Sea. Japanese Journal of Ichthyology 30(3): 301-307 figs 1-2

    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. 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 (p. 124, as Lamna whitleyi)

    Quick Facts


    CAAB Code:37010004

    Conservation:IUCN Vulnerable; CITES Listed

    Danger:Potentially dangerous

    Depth:1-1024 m

    Habitat:Pelagic, mesopelagic

    Max Size:3.65m TL; 350 kg

    Species Image Gallery

    Species Maps

    CAAB distribution map