Fast-moving and predatory, Cirolana cranchii looks superficially like a large Eurydice, though it typically a tan colour with brownish mottling. One of the most obvious structural differences is that the peduncle of the uopods is extended, forming a point along the inner side of the endopods. Unlike Eurydice, the peduncle of the antenna has five articles. The pleotelson is also rather more triangluar in shape. Adults of the species are between 9 and 19 mm.
Distribution and Habitat
This is a mainly sublittoral species, commonly being found on the bait in crab and lobster pots, though it occasionally turns up intertidally, especially after storms, on south-westerly shores.
Bruce, N. & Ellis, J. 1983. Cirolana cranchii Leach, 1818 (Crustacea: Isopoda: Cirolanidae) redescribed, with notes on its distribution. Bulletin of the British Museum (Natural History) 44(2), 75-84.
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.