Cold-water coral associated fauna in the Mediterranean Sea and adjacent areas

Cold-water corals are recognised as a key component of Mediterranean deep-sea ecosystems but the knowledge of their associated biodiversity is still limited. To date, the fauna associated to the Central Mediterranean cold-water coral habitats is the best known (e.g. the cold-water coral provinces of Santa Maria di Leuca, Bari canyon and Strait of Sicily) but such knowledge should be extended to the whole Mediterranean Basin. The combined biodiversity censed so far for Mediterranean cold-water coral habitats and those of adjacent areas (Strait of Gibraltar-Gulf of Cádiz) includes a conspicuous number of species (ca. 520 spp.) with a high representation of sponges (ca. 90 spp.), polychaetes (ca. 90 spp.), cnidarians (ca. 80 spp.), bryozoans (ca. 75 spp.), crustaceans (ca. 60 spp.), molluscs (ca. 50 spp.), fishes (ca. 50 spp.), echinoderms (ca. 20 spp.) and brachiopods (7 spp.). Most species are not univocally linked to cold-water corals, but they benefit from the complex and diverse microhabitats provided by them. There is a clear need to continue the investigation of Mediterranean cold-water coral habitats to fully document the faunistic inventory, biogeographic connections and functions of the many species connected to such emblematic ecoystems of the deep-sea.