information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

Spiny dogfish (Squalus acanthias)

Distribution data supplied by the Ocean Biogeographic Information System (OBIS). To interrogate UK data visit the NBN Atlas.
Only coastal and marine records shown



The spiny dogfish or spurdog Squalus acanthias is a small member of the dogfish family reaching up to 1.6 m in length. It has a grey to brown dorsal colouring and a much paler belly. It can easily be distinguished from similar species by conspicuous white spots covering the entire body. It has two dorsal fins each with large spines. The caudal fin outline is smooth.

Recorded distribution in Britain and Ireland

Widely distributed throught the British and Irish coastal waters.

Global distribution



The spiny dogfish is a benthopelagic species occuring both inshore and offshore of the upper continental shelf. Tolerant of a wide range of salinities.

Depth range


Identifying features

  • Small dogfish up to 1.6 m in length.
  • Grey-brown upper body, paler lower body.
  • Entire body covered in white spots.
  • Two dorsal fins each with ungrooved large spines.
  • The first dorsal spine originates behind the pectoral rear tips.
  • Lateral keels on the caudal peduncle and upper precaudal pit.
  • Anal fin and notch on the caudal fin are absent.

Additional information

One of the most abundant shark species in the world, Squalus acanthias is a well studied species and has been the subject of many studies focusing on heavy metal pollution and sensitivity to pollution studies (McMillan & Morse, 1999).

Listed by

Further information sources

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  1. Compagno, L.J.V., 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1 - Hexanchiformes to Lamniformes. FAO Fisheries Synopsies, 125, 1-249

  2. Fahy, E., 1988. Recent developments in the Irish fisheries for spurdog, Squalus acanthias (L.). ICES Council Meeting Papers, C.M.1988/H:6

  3. Froese, R. & Pauly, D., 2007. Fishbase. A global information system on fishes. [On-line], 2008-02-18

  4. Henderson, A.C., Flannery, K. & Dunne, J., 2002. Growth and reproduction in spiny dogfish Squalus acanthias L. (Elasmobranchii: Squalidae), from the west coast of Ireland. Sarsia, 87, 350-361

  5. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  6. McMillan, D.G. & Morse, W.W., 1999. Essential Fish Habitat Source Document: Spiny Dogfish, Squalus acanthias, Life History and Habitat Characteristics. NOAA Technical Memorandum, NMFS-NE-150

  7. National Biodiversity Network (NBN) Atlas website. Available from:  Accessed 01 April 2017

  8. OBIS,  2018. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2018-09-19

  9. Picton, B.E. & Costello, M.J., 1998. BioMar biotope viewer: a guide to marine habitats, fauna and flora of Britain and Ireland. [CD-ROM] Environmental Sciences Unit, Trinity College, Dublin.

  10. Vince, M.R., 1991. Stock identity in spurdog (Squalus acanthias L.) around the British Isles. Fisheries Research, 12, 341-354


This review can be cited as:

Barnes, M.K.S. 2008. Squalus acanthias Spiny dogfish. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 19-09-2018]. Available from:

Last Updated: 25/03/2008