Sea lamprey (Petromyzon marinus)

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



Lampreys belong to a group of vertebrates known as Agnatha which means 'jawless fish'. Their mouth is a toothed circular sucking disk. They have long elongated eel-like bodies. They can also be recognised by their gills which open directly to each side of the head in the form of a line of seven gill holes behind the eye. The back and sides of Petromyzon marinus have a distinctly mottled colour pattern with a brown-yellow dorsal and lateral colouring. It usually reaches over 50 cm in length.

Recorded distribution in Britain and Ireland

Occurs offshore throughout the UK and Ireland, migrating upstream many British and Irish rivers in August to spawn .

Global distribution



Petromyzon marinus is a demersal and anadromous species found in a wide range of riverine and offshore habitats.

Depth range


Identifying features

  • Long eel-like body over 50 cm in length.
  • Brown-yellow dorsal and lateral colouring with black marblings.
  • Circular sucking disk for a mouth with sharp teeth.
  • Seven conspiculous gill holes in a line behind the eye.
  • Scales, paired fins and gill covers are absent.

Additional information

Relatively easily distinguished from the river lamprey Lampetra fluviatilis and the brook lamprey Lampetra planeri by its considerably larger size and distinctly mottled colour pattern (Igoe et al., 2004).


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  4. Igoe, F., Quigley, D.T.G., Marnell, F., Meskell, E., O'Connor, W. & Byrne, C., 2004. The sea lamprey Petromyzon marinus (L.), river lamprey Lampetra fluviatilis (L.) and brook lamprey Lampetra planeri (Bloch) in Ireland: general biology, ecology, distribution and status with recommendations for conservation. Biology and Environment. Proceedings of the Royal Irish Academy, Section B, 104B-S, 43-56.

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  6. Schreiber, A. & Engelhorn, R., 1998. Population genetics of a cyclostone species pair, river lamprey (Lampetra fluviatilis L.) and brook lamprey (Lampetra planeri, Bloch). Journal of Zoological Systematics and Evolutionary Research, 36, 85-99


  1. Bristol Regional Environmental Records Centre, 2017. BRERC species records within last 15 years. Occurrence dataset: accessed via on 2018-09-25.

  2. Cambridgeshire & Peterborough Environmental Records Centre, 2017. CPERC Combined Dataset. Occurrence dataset: accessed via on 2018-09-25.

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

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

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

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

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

  8. Norfolk Biodiversity Information Service, 2017. NBIS Records to December 2016. Occurrence dataset: accessed via on 2018-10-01.

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

  10. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-06-15

  11. Outer Hebrides Biological Recording, 2018. Vertebrates (except birds, INNS and restricted records), Outer Hebrides. Occurrence dataset: accessed via on 2018-10-01.

  12. Record, 2018. RECORD Freshwater Fish Data. Occurrence dataset accessed via on 2018-10-01

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

  14. Suffolk Biodiversity Information Service., 2017. Suffolk Biodiversity Information Service (SBIS) Dataset. Occurrence dataset: accessed via on 2018-10-02.


This review can be cited as:

Barnes, M.K.S. 2008. Petromyzon marinus Sea lamprey. 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 15-06-2024]. Available from:

Last Updated: 27/03/2008