Horse mackerel (or scad) (Trachurus trachurus)

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



The horse mackerel Trachurus trachurus is a slender schooling species that may reach up to 60 cm in length. The leading rays of its dorsal, anal and pelvic fins have conspicuous spines. It has two dorsal fins, the first of which is short and tall. The second dorsal fin, like the anal fin, is prolonged from the end of the first dorsal almost to the tail. The tail itself is strongly forked. It has a bluish dorsal colouring and silvery sides. It has a large head with large eyes. It has a black spot on the trailing edge of the gill cover, between the pectoral fin and the lateral line.

Recorded distribution in Britain and Ireland

The horse mackerel has a south-western distribution and can be found in throughout the English Channel, in the Irish Sea as far north as Lancashire and off the south coast of Ireland.

Global distribution



The horse mackerel is a pelagic coastal species that may be found on continental shelves down to over 200 m in depth.

Depth range


Identifying features

  • Fairly compressed elongate body up to 60 cm in length.
  • Large head.
  • Lower jaw projected.
  • First dorsal fin tall.
  • Second dorsal and anal fins prolonged.
  • Black spot on the trailing edge of the gill cover.

Additional information

The horse mackerel Trachurus trachurus can be easily distinguished from other mackerel by the black spot on the trailing edge of the gill cover (Knijn et al., 1993).


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

  2. 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.]

  3. Knijn, R.J., Boon, T.W., Heesen, H.J.L & Hislop, J.R.G., 1993. Atlas of North Sea Fishes. ICES cooperative research reports. ICES 194., Copenhagen

  4. Macer, C.T., 1977. Some aspects of the biology of the horse mackerel (Trachurus trachurus L.) in waters around Britain. Journal of Fish Biology, 10, 51-62

  5. Moen, F.E. & Svensen, E., 2004. Marine Fish & Invertebrates of Northern Europe. Southend-on-Sea: Aqua Press.

  6. 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.

  7. Whitehead, P.J.P., Bauchot, M.-L., Hureau, J.-C., Nielson, J. & Tortonese, E. 1986. Fishes of the North-eastern Atlantic and the Mediterranean. Vol. I, II & III. Paris: United Nations Educational, Scientific and Cultural Organisation (UNESCO).


  1. Environmental Records Information Centre North East, 2018. ERIC NE Combined dataset to 2017. Occurrence dataset: accessed via on 2018-09-38

  2. Fenwick, 2018. Aphotomarine. Occurrence dataset Accessed via on 2018-10-01

  3. Isle of Wight Local Records Centre, 2017. IOW Natural History & Archaeological Society Marine Records. Occurrence dataset: accessed via on 2018-09-27.

  4. Kent & Medway Biological Records Centre, 2017. Fish: Records for Kent.. Occurrence dataset accessed via on 2018-09-27.

  5. Kent Wildlife Trust, 2018. Kent Wildlife Trust Shoresearch Intertidal Survey 2004 onwards. Occurrence dataset: accessed via on 2018-10-01.

  6. Merseyside BioBank., 2018. Merseyside BioBank (unverified). Occurrence dataset: accessed via on 2018-10-01.

  7. NBN (National Biodiversity Network) Atlas. Available from:

  8. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-07-22


This review can be cited as:

Barnes, M.K.S. 2008. Trachurus trachurus Horse mackerel (or scad). 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 22-07-2024]. Available from:

Last Updated: 22/05/2008