A review of carnivorous sponges (Porifera: Cladorhizidae) from the Boreal North Atlantic and Arctic
Hestetun, Jon Thomassen;
Rapp, Hans Tore
Family Cladorhizidae, comprising the carnivorous sponges, represents a unique innovation within the phylum Porifera. Rather than filter feeding, carnivorous sponges have developed the ability to passively capture small invertebrates such as crustaceans using filaments or other appendages, coupled with an adhesive surface and the ability of sponge cells to migrate to and envelop prey items. Cladorhizids are most commonly deep-sea species and are found worldwide, with around 150 species currently described. The boreal Atlantic and neighbouring Arctic areas have a species-rich cladorhizid fauna, including many of the first cladorhizids described from early marine biological investigations. While a number of records exist for parts of these areas, other areas, such as the North-west Atlantic, are less well known, and species descriptions are scattered and in many cases lacking necessary information. Using a large set of specimens from newly collected material and multiple museum collections, and integrating this with previously published records from the area, we provide an overview of the cladorhizid fauna of the boreal Atlantic and adjoining Arctic Oceans. In all, we provide updated descriptions of 25 species, of which four, Asbestopluma (Asbestopluma) ruetzlerisp. nov.,Cladorhiza kenchingtonaesp. nov.,Lycopodina novangliaesp. nov. and L. tendalisp. nov., are previously undescribed. We also provide an overview of the known distribution and depth ranges of each species as well as a key for identification to species level. Finally, we provide some general discussion on the boreo-Atlantic and Arctic cladorhizid fauna and its relationship to neighbouring areas.
Numerous people have helped us for different parts of this study: We are greatly indebted to Ole S. Tendal for his help in providing access to the large number of cladorhizids found in the zoological collections at the Natural History Museum of Denmark. We would like to thank Megan Best for collecting SEM images of DFO specimens, and Ellen Kenchington and Tim Siferd for providing access to DFO specimens and data. We would like to thank Elena Gerasimova for help and training in making thin sections for species descriptions, and Lindsay Beazley and Lynne Anstey for providing records from benthic imagery and assisting with barcoding of specimens, respectively. We would like to thank Emma Sherlock at the Museum of Natural History (London), Eric Lazo-Wasem at the Yale Peabody Museum, Klaus Rützler and William Moser from the Smithsonian Institution Museum of Natural History, Torkild Bakken from the NTNU University Museum, Anne Helene Tandberg and Jon Anders Kongsrud at the University Museum of Bergen and the MAREANO program, and Rob van Soest and Elly Beglinger at the Naturalis Biodiversity Center for assistance in borrowing samples from their respective collections. We would also like to thank Javier Cristobo, Pilar Ríos, Jean Vacelet, Nicole Boury-Esnault and Michelle Kelly for sending additional samples or subsamples for study or comparison, and Saskia Brix (Senckenberg Naturmuseum Frankfurt) for inviting us to take part in the IceAge project. We would like to thank Nataliya Budaeva and Alexander Plotkin for help in obtaining and translating Russian sources. Finally, we would like to thank Javier Murillo for proofreading and providing input on the manuscript.
This study was supported by the Norwegian Biodiversity Information Centre (grant to HTR, project number 70184219), the Norwegian Academy of Science and Letters (grant to HTR) and the Research Council of Norway (through contract number 179560). This work has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 679849 (the SponGES project). The project was supported by an NSERC Visiting Fellowship to Gabrielle Tompkins MacDonald and Intergovernmental Strategy (IGS) funding.