Fauna Europaea: Annelida - Hirudinea, incl. Acanthobdellea and Branchiobdellea.

Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Hirudinea is a fairly small group of Annelida, with about 680 described species, most of which live in freshwater habitats, but several species are (sub)terrestrial or marine. In the Fauna Europaea database the taxon is represented by 87 species in 6 families. Two closely related groups, currently treated as distinct lineages within the Annelida, are the Acanthobdellea (2 species worldwide, of which 1 in Europe) and the Branchiobdellea (about 140 species worldwide, of which 10 in Europe). This paper includes a complete list of European taxa belonging to the Hirudinea, Acanthobdellea and Branchiobdellea. Recent research on a limited number of taxa suggests that our current appreciation of species diversity of Hirudinea in Europe is still provisional: on the one hand, cryptic, unrecognised taxa are expected to emerge; on the other, the status of some taxa currently treated as distinct species deserves revisiting.