This is a small Sphaeromatid isopod with marked sexual dimorphism. Distinguished from other species by having a single uropod ramus, the pleotelson of females is rounded whilst males have a long projection from pereonite 6 which extends to the distal border of the pleotelson. Males grow up to 4.0mm, females up to 3.5mm.
Distribution and Habitat
Restricted to south-western British shores, Campecopea hirsuta is most commonly found in the intertidal lichen Lichina pygmaea ((Lightf.) C. Agardh, 1817), amongst barnacles and in rock crevices on exposed shores between MTL and HWN. It is most easily found by scraping some Lichina pygmaea into a tray of water, where the species may then be seen swimming freely.
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.