Sponges from bathyal depths (1000–1750 m) in the Western Mediterranean Sea

Abstract

Abstract This note deals with a study of sponge fauna at seven deep stations (1000–1750 m) in the Western Mediterranean Sea. The species found exhibit a broad geographical distribution, mainly centred in the Northern Atlantic Ocean. Trichostemma sarsi and Hyalonema thomsoni are recorded for the first time in the Mediterranean Sea, and the known bathymetric distribution of Polymastia tissieri has been considerably enlarged. Some taxonomic problems involving the genera Trichostemma, Radiella and Polymastia and the species Hyalonema thomsoni and H. infundibulum are discussed, and arguments supporting the reclassification of the species Radiella tissieri under the genus Polymastia are put forward. Keywords : SystematicsDemospongiaeHexactinellidaBathyal depthsWestern Mediterranean