Hermit Crabs of the Northeastern Atlantic Ocean and Mediterranean Sea

Hermit crabs are usually recognized by their soft, spiral shaped abdomens and are normally concealed within other gastropod shells. There are probably over 800 species world wide and to date 46 of these occur in northeastern Atlantic and Mediterranean waters. Some offshore waters are densely populated with hermit crabs. Although they often form a significant part of the total bottom biomass, their role in the ecology of faunal communities is little understood at present. Hermit crabs have also provided excellent models for studying crustacean agonistic behaviour which is very evident during shell changing phases. Likewise, some species have interesting symbiotic relationships with anthozoans. In any study of hermit crabs, correct identification to species level is of considerable importance. Whereas a number of identification guides to this group have been published during the past 50 years, none can be considered comprehensive enough for identifying all species inhabiting the northeastern Atlantic ocean and Meditteranean sea. The present guide aims to provide taxonomic keys to all known species from these regions. Detailed illustrations, synonyms, taxonomic descriptions and distributions are given for all species belonging to the Diogenidae and Paguridae; these families include the majority of the species. The various specialized terms used in hermit crab taxonomy are fully explained and illustrated and a comprehensive bibliography is provided to papers relevent to the regions.