Ectosymbiosis is a critical factor in the local benthic biodiversity of the Antarctic deep sea.

• Published in: Marine Ecology Progress Series
• Main Authors: Hétérier, Vincent, DAVID, Bruno, De Ridder, Chantal, Rigaud, Thierry
• Other Authors: Biogéosciences UMR 6282 Dijon (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie marine, Université libre de Bruxelles (ULB), Supported by the Belgian Science Policy (PADDII projects), and by a PhD grant from the Belgian Science Policy.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: Symbiosis; Species diversity; Species abundance; Null models; Cidaroids; Weddell Sea; geo; envir; Antarctic; The Antarctic; Weddell; Antarc*; Antarctica
• Online Access: https://doi.org/10.3354/meps07487; https://hal.archives-ouvertes.fr/hal-00322205

International audience In deep-sea benthic environments, competition for hard substrates is a critical factor in the distribution and diversity of organisms. In this context, the occurrence of biotic substrates in addition to mineral substrates may change the characteristics of sessile fauna. We tested this hypothesis at different localities of the Weddell Sea (Antarctica) by studying the diversity of ectosymbionts living on the spines of cidaroids (echinoids). The presence of cidaroids promoted a higher total specific richness and increased sessile species abundance, but did not change the diversity. Analyses of species distribution suggested that the cidaroids are a favourable habitat for sessile organisms, compared to rocks, but are colonized by relatively specialist sessile species, leaving the unfavourable rock habitat to more generalist species. Therefore, our study highlights the role of some living organisms, such as cidaroids, as key species increasing Antarctic benthic deep-sea species richness through the niche they provide to symbiotic species. 10 pages