Van Soest, R.W.M.; van Duyl, F.C.; Maier, C.; Lavaleye, M.S.S.; Beglinger, E.J.; Tabachnick, K.R. (2007). Mass occurrence of Rossella nodastrella Topsent on bathyal coral reefs of Rockall Bank, W of Ireland (Lyssacinosida, Hexactinellida). pp 645-652 In: Custódio MR, Lôbo-Hajdu G, Hajdu E, Muricy G (eds) Porifera Research. Biodiversity, Innovation and Sustainability. Livros de Museu Nacional 28, Rio de Janeiro.
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Van Soest, R.W.M.; van Duyl, F.C.; Maier, C.; Lavaleye, M.S.S.; Beglinger, E.J.; Tabachnick, K.R.
2007
Mass occurrence of <i>Rossella nodastrella</i> Topsent on bathyal coral reefs of Rockall Bank, W of Ireland (Lyssacinosida, Hexactinellida). pp 645-652 <i>In</i>: Custódio MR, Lôbo-Hajdu G, Hajdu E, Muricy G (eds) Porifera Research. Biodiversity, Innovation and Sustainability. Livros de Museu Nacional 28, Rio de Janeiro
Publication
Proceedings of the 7th International Sponge Conference, Buzios
Available for editors
We report on the mass occurrence of a hexactinellid species, Rossella nodastrella Topsent, 1915 in coldwater coral reefs W of Ireland. The species was until now known only from the holotype, a single small specimen collected off the Azores. In recent boxcore sampling at a reef mound situated in 580 m water at 55.4°N 15.7°W along the south-eastern slope of Rockall Bank numerous specimens of this species were collected, showing a range of morphologies from 1 cm high, spiny urn-shaped individuals to megabenthic cup-shaped forms of 30-40 cm high and wide. We provide an extensive redescription of the species including SEM images of all the microscleres. Underwater video transects showed this species to be densely concentrated, up to approx. 6 specimens per m2, over a distance of more than 1 km. Presence of individuals was negatively correlated with live coral cover. This dense concentration was a local phenomenon, because the species was virtually absent in nearby similar habitats.
