Taxonomic Investigations on Cladorhizidae (Carnivorous Sponges) of the East Scotia Ridge (Antarctica) with the Description of Three New Species

This study investigates taxonomic characteristics of carnivorous sponges from the Southern Ocean. The specimens were collected in 2010 from deep-sea hydrothermal vents of the East Scotia Ridge during the RRS James Cook Cruise JC42. All the investigated sponges are new to science. They belong to the genera Abyssocladia and Cladorhiza within the family Cladorhizidae. This study provides descriptions and remarks for the three new species Abyssocladia truespacemeni, Abyssocladia hendrixii and Cladorhiza elsaae. Comparative faunistic and ecological aspects of these sponge genera within the Southern Ocean sponge fauna are discussed. The genera Abyssocladia and Cladorhiza are recorded here for the first time from the ecosystem around hydrothermal vents in the Antarctic deep sea. The descriptions of new species contribute to and expand the current knowledge of the Cladorhizidae and consequently support future taxonomic identifications and descriptions of Antarctic deep-sea carnivorous sponges. The appearance of these newly discovered species underlines the hypothesis that Cladorhizidae is the second most species-rich family of Demospongiae in the Southern Ocean, and many new species of this deep-sea sponge family are still to be discovered.