Chelicerata are a basically terrestrial group of invertebrates, including many clades whose representatives have never found an evolutionary way to aquatic live. An exception is made by the spiders, which include a considerable number of hygrophilous species, and by the highly diverse aquatic mites which in inland water habitats are represented by members of numerous different clades having evolved an aquatic or amphibious lifestyle. For the first time the present taxonomic knowledge about these different groups of invertebrates is brought together in an overview for the Central-European fauna. This volume includes taxonomic keys and ecological information concerning hygrophilous and aquatic spiders, a general introduction to mites, and the treatment of three mite groups generally known from terrestrial habitats. Also, the freshwater-dwelling representatives of the originally marine Halacaridae are treated, and the species-rich true freshwater mites (Hydrachnidia) are represented in ageneral overview.
