Limnoria tripunctata Menzies, 1951



ID Difficulty


Limnoria are small (up to 3-4 mm) but distinctive wood-boring marine isopods. The three species that have been recorded on British and Irish shores can be distinguished by the patterning of raised areas on the fifth pleonite and on the pleotelson, though these can be hard to discern.

L. tripunctata is the least common species. It is distinguishable from L. lignorum and L. quadripunctata by the presence of two tubercles on the fifth pleonite and by three tubercles on the pleotelson.

Distribution and Habitat

L. tripunctata is restricted to south Wales and south-west England (Jones 1963), particularly in areas (e.g. around power stations) where the temperature of the water is artificially heated. When it occurs together with L. lignorum and L. quadripunctata, it occupies the upper zone of wood pilings.


Jones, L. 1963. The geographical and vertical distribution of British Limnoria [Crustacea: Isopoda]. Journal of the Marine Biological Association of the U.K., 43, 589-603.

Naylor, E. & A. Brandt. 2015. Intertidal Marine Isopods. Synopses of the British Fauna (New Series), No. 3. Field Studies Council, for The Linnean Society of London.

BRC code