Spiny dogfish (Squalus acanthias)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



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).


  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] http://www.fishbase.org, 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. 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.

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


  1. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  2. Environmental Records Information Centre North East, 2018. ERIC NE Combined dataset to 2017. Occurrence dataset: http://www.ericnortheast.org.ukl accessed via NBNAtlas.org on 2018-09-38

  3. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01

  4. Isle of Wight Local Records Centre, 2017. IOW Natural History & Archaeological Society Marine Records. Occurrence dataset: https://doi.org/10.15468/7axhcw accessed via GBIF.org on 2018-09-27.

  5. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  6. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-05-18

  7. Scottish Shark Tagging Programme, 2018. Capture Mark Recapture Data for Scottish Elasmobranchs: 2009-2018. Occurrence dataset: https://doi.org/10.15468/znol4z accessed via GBIF.org on 2018-10-02.


This review can be cited as:

Barnes, M.K.S. 2008. Squalus acanthias Spiny dogfish. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 18-05-2024]. Available from: https://www.marlin.ac.uk/species/detail/68

Last Updated: 25/03/2008