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

Fin whale (Balaenoptera physalus)

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



Balaenoptera physalus is a baleen whale and can be recognised as such by the plates of baleen (rather than teeth) suspended from the upper jaw and the two blowholes on the upper body. The fin whale is slender bodied and can reach up to 24 m in length. It is a member of the rorqual family with the characteristic ventral pleats of skin under the eye and the relatively flat and broad jaw. The ventral pleats extend beyond the navel. The small flippers are less than one-fifth of the body length. It has only one prominent ridge on the snout. The head is pointed and V-shaped, the dorsal fin is a moderate size and set less far back on the body, and the head colouration is asymmetrical. The fin whale has a dark dorsal and lateral colouration with light streaks and the belly is white. The left side of the head is grey, while much of the right side is white in colour.

Recorded distribution in Britain and Ireland

Occasionally seen off the coasts of northern and north-western Scotland and southern Ireland.

Global distribution



The fin whale is an open ocean whale, not often seen near the coast in north-west Europe. It can be found at the surface or diving down to over 230 metres in depth.

Depth range


Identifying features

  • Up to 24 m in length.
  • Dark dorsal and lateral colouration with light streaks; the belly is white.
  • Left side of head is grey, right side is white.
  • Broad tail flukes from tip to tip.
  • Medium-sized dorsal fin set two-thirds down the body.
  • Up to 100 ventral pleats ending past the navel.

Additional information

The fin whale can be confused with the blue whale Balaenoptera musculus but can be recognised by the pointed and V-shaped head with an asymmetrical colouration and the moderate sized dorsal fin that is set less far back on the body. Fin whales are often slightly more social than other rorquals and tend to gather in pods of up to 7 or more individuals. It does occassionally breech but when diving, rarely show the tail flukes. Dives may last up to 10 minutes long (Kinze, 2002).

Listed by

Further information sources

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  1. Bruyns, W.F.J.M., 1971. Field guide of whales and dolphins. Amsterdam: Publishing Company Tors.

  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. Jefferson, T.A., Leatherwood, S. & Webber, M.A., 1994. FAO species identification guide. Marine mammals of the world. Rome: United Nations Environment Programme, Food and Agriculture Organization of the United Nations.

  4. Kinze, C. C., 2002. Photographic Guide to the Marine Mammals of the North Atlantic. Oxford: Oxford University Press.

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

  6. Reid. J.B., Evans. P.G.H., Northridge. S.P. (ed.), 2003. Atlas of Cetacean Distribution in North-west European Waters. Peterborough: Joint Nature Conservation Committee.

  7. Smith, T.D. (ed.), 2008. World Whaling Database: Individual Whale Catches, North Atlantic. In: M.G Barnard & J.H Nicholls, HMAP Data Pages., 2008-03-13


This review can be cited as:

Barnes, M.K.S. 2008. Balaenoptera physalus Fin whale. 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: 24/06/2008