14 Taxonomy, Genetics and Biodiversity of Mediterranean Deep-Sea Corals and Cold-Water Corals

Abstract

Within the Mediterranean basin there are 82 species of deep-sea corals belonging to six orders of the phylum Cnidaria (Antipatharia, Scleractinia, Zoantharia, Alcyonacea, Pennatulacea and Anthoathecata), with the Alcyonacea (40) and the Scleractinia (25) being the most speciose. Thirteen species have a pronounced habitat-building ability at depths >200 m. Remarkable sites characterised by rich coral frameworks and gardens have been found in biodiversity surveys during the last years, revealing that some species are more abundant than previously thought. However, in terms of species richness, the Mediterranean deep-sea coral fauna is less diverse when compared with the nearby Atlantic areas. This discrepancy is probably in part due to unfavourable environmental conditions of the deep Mediterranean Sea, and to differences in sampling efforts between both areas. In this respect, considerable efforts have been recently done in terms of deep-sea fauna inventories. Nevertheless, updates made to the Mediterranean inventory of deep-sea corals since the beginning of the twenty-first century are few except for the octocorals. Therefore, ten species were included to the Mediterranean inventory, among which two have been newly described. The species concerned belong to the orders Scleractinia (1), Pennatulacea (1) and Alcyonacea (8).