Atlantic halibut (Hippoglossus hippoglossus)

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



Highly sought after commercially, the Atlantic halibut is the largest flatfish in the world reaching up to 2.5 m in length. It is a right-handed flatfish. The visible upper side of its laterally compressed body is usually dark brown to dark olive green in colour. The underside is a dirty white. Younger specimens may appear paler in colour and show a mottled pattern. Both eyes are positioned close together on its right side. It has a gaping mouth which extends back as far as the eyes.

Recorded distribution in Britain and Ireland

Historically found throughout British and Irish waters although the current distribution is relatively unknown.

Global distribution



Hippoglossus hippoglossus is a predominantly benthic and demersal species or more infrequently pelagic. They are usually found on sand, gravel, or clay substrates and not on soft mud or on a rocky seabed.

Depth range


Identifying features

  • Large, right-eyed flatfish up to 2.5 m in length.
  • Uniform dark brown to dark olive colouring on the upper surface, often paler and more mottled in younger fish.
  • Continuous dorsal fin which has longer rays in the centre.
  • The rear edge of its tail fin is concave, not rounded.
  • The two ventral fins are alike.
  • The lateral line is strongly curved above the pectoral fin unlike Reinhardtius hippoglossoides.

Additional information

Atlantic halibut feed mainly on other fish (cod, haddock, pogge, sand-eels, herring, capelin) but also targets cephalopods, large crustaceans and other bottom-living animals. Due to slow growth rates and late onset of sexual maturity, Hippoglossus hippoglossus populations can be seriously affected by overfishing (Muus & Nielsen, 1999).


  1. Cargnelli, L.M., Griesbach, S.J. & Morse, W.W., 1999. Essential Fish Habitat Document: Atlantic halibut, Hippoglossus hippoglossus, Life history and habitat characteristics. National Oceanic and Atmospheric Administration (NOAA) Technical Memorandum, NMFS-NE-125.

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

  3. Haug, T., 1990. Biology of the Atlantic halibut, Hippoglossus hippoglossus (L., 1758). Advances in Marine Biology, 26, 1-70

  4. 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.]

  5. Muus, B.J. & Nielsen, J.G. 1999. Sea Fish. Scandinavian Fishing Year Book. Hedehusene: Denmark

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

  3. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-05-25


This review can be cited as:

Barnes, M.K.S. 2008. Hippoglossus hippoglossus Atlantic halibut. 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 25-05-2024]. Available from:

Last Updated: 25/03/2008