Marine Isopods of Britain and Ireland

Submitted by Warren Maguire on


This checklist is mostly (though with various additions and updates) based on Naylor & Brandt (2015) Intertidal Marine Isopods, which itself is an update of Naylor (1972). Ernst Naylor also contributed the section on marine isopods in Hayward & Ryland (2017) Handbook of the Marine Fauna of North-west Europe, which includes information on a number of other north-east Atlantic species that have subsequently been found in British waters. A useful, non-technical introduction to finding and identifying the more common and obvious marine isopods can be found in Hatcher & Trewhella (2019) The Essential Guide to Rockpooling.

In addition to intertidal species, the list includes a number of sublittoral isopods that may sometimes be encountered in the intertidal zone or in inshore waters, but it excludes strictly offshore species. Nomenclature follows the current World List of Marine, Freshwater and Terrestrial Isopod Crustaceans (

Click on a species name to access its brief species account, outlining identification, distribution and habitats preferences.

  • Hatcher J. & S. Trewhella. 2019. The Essential Guide to Rockpooling, Wild Nature Press.
  • Hayward, P. & J. Ryland. 2017. Handbook of the Marine Fauna of North-west Europe (2nd Edition). Oxford: Oxford University Press.
  • Naylor E. 1972. British Marine Isopods. The Linnean Society of London. London & New York: Academic Press.
  • Naylor E. & A. Brandt. 2015. Intertidal Marine Isopods, Synopsis of the British Fauna (New Series), No. 3. The Linnean Society of London: FSC.


Intertidal Marine Isopods of Britain and Ireland: systematic check list

Order: Isopoda
Suborder: Cymothoida
Superfamily: Cymothooidea
Family: Gnathiidae
Family: Cymothoidae
Superfamily: Cirolanoidea
Family: Cirolanidae
Superfamily: Cryptoniscoidea
Family: Cabiropidae
Family: Cryptoniscidae
Family: Hemioniscidae
Superfamily: Anthuroidea
Family: Anthuridae
Superfamily: Bopyroidea
Family: Bopyridae
Family: Entoniscidae
Family: Dajidae
Suborder: Sphaeromatidea
Superfamily: Sphaeromatoidea
Family: Sphaeromatidae
Suborder: Limnoriidea
Superfamily: Limnorioidea
Family: Limnoriidae
Suborder: Valvifera
Family: Idoteidae
Family: Holognathidae
Family: Arcturidae
Suborder: Asellota
Superfamily: Janiroidea
Family: Janiridae
Family: Munnidae
Family: Joeropsididae
Suborder: Oniscidea
Family: Ligiidae