Allis shad (Alosa alosa)

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



Alosa alosa is a herring-like, planktivorous fish with silvery white sides and a deep blue colouration on its back. It is most commonly recorded at a size between 30 -50 cm but has been reported to reach 70 cm. Like other shads its upper jaw is distinctly notched in the mid line and the gill cover has distinct radiating ridges.

Recorded distribution in Britain and Ireland

A coastal species recorded from many areas around the British Isles. Known spawning populations exist in the River Tamar with other possible spawning sites in the English and Bristol Channels and the Solway Firth.

Global distribution

Atlantic Coasts, from Northern Africa to Scandinavia and western parts of the Mediterranean


Coastal waters returning to freshwater to spawn above gravel substrates. Alosa alosa has been reported in depths ranging from 10 -150 m.

Depth range


Identifying features

  • Dorsal profile of the allis shad is curved and the tail fins are forked.
  • Body flattened side to side with strong spines along the belly.
  • Deep bodied with silvery scales.
  • Back deep blue in colour with silvery white sides.
  • Dark spot behind the gill cover (sometimes absent).
  • Grows up to 70 cm length.

Additional information

The allis shad is distinguished from the other European shad, the twaite shad (Alosa fallax), by having between 80-130 gill rakers on the first gill arch while Alosa fallax has between 40-60. The allis shad is 'anadromous' in that it spends its life in the ocean but enters rivers in April and May to spawn before returning to the sea. Juveniles remain in the rivers for up to 24 months.


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  2. FishBase, 2000. FishBase. A global information system on fishes. [On-line], 2001-05-03

  3. Henderson, P.A., 2003. Background information on species of shad and lamprey. Countryside Council for Wales, Bangor. (CCW Marine Monitoring Report No.7).

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  7. Sewell, J. & Hiscock, K., 2005. Effects of fishing within UK European Marine Sites: guidance for nature conservation agencies. Report to the Countryside Council for Wales, English Nature and Scottish Natural Heritage from the Marine Biological Association. Plymouth, Marine Biological Association. [CCW Contract FC 73-03-214A].

  8. Wheeler, A., 1969. The fishes of the British Isles and north-west Europe. London: Macmillan.

  9. 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. Cofnod – North Wales Environmental Information Service, 2018. Miscellaneous records held on the Cofnod database. Occurrence dataset: accessed via on 2018-09-25.

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

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

  4. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-07-14

  5. South East Wales Biodiversity Records Centre, 2018. SEWBReC Fish (South East Wales). Occurrence dataset: accessed via on 2018-10-02.


This review can be cited as:

Reeve, A. 2005. Alosa alosa Allis shad. 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 14-07-2024]. Available from:

Last Updated: 30/06/2005