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

Haddock (Melanogrammus aeglefinus)

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



The common haddock Melanogrammus aeglefinus is a member of the cod-like fish family. Members have an elongate, tapering body and usually long dorsal and anal fins. Haddock have three dorsal fins and two anal fins. They are easily recognised by the first dorsal fin which is considerably higher than the others, more triangular in outline and has a slightly concave trailing margin. The lateral line is dark in colouration. The haddock has a short and rounded nose, big eyes and a small mouth. It is grey in colouration with dusky brown blotches.

Recorded distribution in Britain and Ireland

Found throughout British and Irish waters but more common off the north-eastern Scotland, north-east England, south-western England and the Irish sea.

Global distribution



The common haddock is a demersal species and shoals in colder waters at depths of 40-300 m. It can be found over rock, sand, gravel or shells.

Depth range


Identifying features

  • Dark uninterrupted lateral line.
  • Three dorsal fins, two anal fins.
  • Dark spot below first dorsal fins.
  • First dorsal fin is high, triangular and has a concave trailing margin.
  • Short and rounded nose and big eyes.
  • Small mouth, not gaping back to below the eye.

Additional information

Melanogrammus aeglefinus is a valuable species that is exploited commercially in mixed trawl and seine fisheries, along with cod (Gadus morhua) and whiting (Merlangius merlangus), and is a bycatch in Norway lobster (Nephrops norvegicus) fisheries (Hedger et al., 2004). Spawning takes place from March to May, at depths of 100-150 m (Alekseeva & Tormosova, 1979). The easiest ways to tell a haddock from a cod (Gadus morhua) are by the dark colouring of the lateral line and the presence of a dusky blotch just below either of the first dorsal fins.

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Further information sources

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  1. Alekseeva, E.I. & Tormosova, I.D., 1979. Maturation, spawning and fecundity of the North Sea haddock, Melanogrammus aeglefinus. Journal of Ichthyology, 19, 56-64

  2. Cargnelli, L.M., Griesbach, S.J., Berrien, P.L., Morse, W.W. & Johnson, D.L., 1999. Essential fish habitat source document: Haddock, Melanogrammus aeglefinus, life history and habitat characteristics. NOAA Technical Memorandum, NMFS-NE-128

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

  4. Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.

  5. Hedger, R., McKenzie, E., Heath, M., Wright, P., Scott, B., Gallego, A., & Andrews, J., 2004. Analysis of the spatial distributions of mature cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) abundance in the North Sea (1980-1999) using generalised additive models. Fisheries Research, 70, 17-25

  6. 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.]

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

  6. North East Scotland Biological Records Centre, 2017. NE Scotland fish records 1800-2010. Occurrence dataset: accessed via on 2018-10-01.

  7. OBIS (Ocean Biogeographic Information System),  2021. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2021-10-28


This review can be cited as:

Barnes, M.K.S. 2008. Melanogrammus aeglefinus Haddock. 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 28-10-2021]. Available from:

Last Updated: 22/05/2008