Bryozoan diversity in the Mediterranean Sea

Abstract

This paper provides a current view of the bryozoan diversity of theMediterranean Sea updating the checklist by Rosso (2003). Bryozoanspresently living in the Mediterranean increase to 556 species, 212genera and 93 families. Cheilostomes largely prevail (424 species, 159genera and 64 families) followed by cyclostomes (75 species, 26 generaand 11 families) and ctenostomes (57 species, 27 genera and 18families). Few families and genera make the bulk of this biodiversitywhereas one third of families are monospecific. The number ofspecies-rank taxa has increased by 81 in the last dozen years but mostof these additions relate to the revision of material from oldcollections and to the introduction of non-indigenous species. Most ofthe bryozoan diversity is distributed in the coralligenous and dark andsemi-dark cave biocoenoses followed by detritic bottoms. Diversitylowers in shallow-water vegetated bottoms and in bathyal habitats. Afurther increase in diversity is expected from investigation of stillpoorly known areas and habitats and the need for rapid assessment isremarked on in view of the management of Mediterranean habitats throughthe EU Marine Strategy Directive.