Monocorophium acherusicum (Amphipoda, Corophiidae), a species commensal to Diogenidae in Arcachon Bay, Bay of Biscay.

Hermit crabs are well-known to shelter many epibiotic, endobiotic or endolithic species in their shell, and examination of shells inhabited by hermit crabs in Arcachon Bay reveals the presence of several such species. Among them is the amphipod Monocorophium acherusicum , a species originally described from European waters and now known to be well distributed throughout the world, but not previously recorded to be commensal with hermit crabs, as reported herein. [ABSTRACT FROM AUTHOR]