Carnivorous sponges from deep-sea coral mounds in the Campos Basin (SW Atlantic), with the description of six new species (Cladorhizidae, Poecilosclerida, Demospongiae)

Abstract

Species of Cladorhizidae are most frequently found associated with hard substrates in the deep sea, close to hydrothermal vents or cold water reefs. Deep sea coral mounds were recently found to occur at Campos Basin, and the ongoing study of these ecosystems has shown that they harbour a diverse sponge fauna. Further results along these lines are reported here, with a (re)description of Asbestopluma (A.) cf. calyx, and six new species from 605 to 1141 m depth: Abyssocladia sp. nov., Asbestopluma (A.) sp. nov. 1–4 and Cladorhiza sp. nov. The fact that all Cladorhizidae come from a relatively small sector of the SE South American slope suggests the diversity of these sponges may still be considerably larger in this area than known so far. The known diversity of cladorhizids in the SW Atlantic ranks intermediate between the richest areas of the NW Pacific (27 species) and the NE Atlantic (23 species), and the poorest ones such as the Mediterranean, the Southeast Atlantic and the whole of the Indian Ocean (1–6 species). Campos Basin yields over 1.5×10⁶ barrels of oil/day, thus generating much concern on the preservation of these ecosystems.

Key words:

• Taxonomy
• Porifera
• azooxanthelate corals
• biodiversity
• distribution
• slope
• Brazil

Acknowledgements

CENPES/PETROBRAS' Research and Development Center is thanked for granting us access to the extraordinary biological samples obtained by the projects OCEANPROF, CAP-BC and ECOPROF. We owe special thanks to Emma Sherlock (The Natural History Museum, London, UK) and Adam Baldinger (Museum of Comparative Zoology, Cambridge, USA) for sending to us important comparative and/or type materials. Prof. Dr. Débora de Oliveira Pires of Museu Nacional/UFRJ is thanked for the identification of scleractinian corals. The authors are also thankful to Elivaldo de Lima and Amanda Garcez da Veiga for SEM operation at the Centre for Scanning Electron Microscopy of Museu Nacional/UFRJ. The establishment of this Centre was made possible by a grant from CENPES/PETROBRAS (Rio de Janeiro, Brazil) and is part of the company's Thematic Network for Marine Environmental Monitoring. CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), CNPQ (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and FAPERJ (Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro) are deeply thanked for the provision of grants and/or fellowships.

Editorial responsibility: Ole S. Tendal