Tosetto E. G. auteur aut IRD Bertrand Arnaud auteur aut IRD Neumann-Leitao S. auteur aut IRD Da Silva A. C. auteur aut IRD Nogueira M. auteur aut IRD text journalArticle eng text/pdf born digital access In marine western boundary systems, strong currents flowing coastward spread oceanic water masses over the continental shelves. Here we propose to test the hypothesis according to which oceanic cnidarian species may dominate western boundary system regions even in coastal waters. For that purpose we use a set of data collected above the shelf, slope and around oceanic seamounts and islands in the Western Tropical South Atlantic. Samples were acquired with a plankton net with 300 mu m mesh size over 34 stations during an oceanographic cruise carried out in October 2015. Results reveal a diverse cnidarian assemblage in the area, extending the known distribution of many species. In addition, the Fernando de Noronha Chain and most of the narrow continental shelf presented a typical oceanic cnidarian community, dominated by holoplanktonic siphonophores. In this western boundary system, this condition was likely driven by the strong currents, which carry the oceanic tropical water and associated planktonic fauna toward the coast. A specific area with reduced influence of oceanic currents presented typical coastal species. The pattern we observed with the dominance of oceanic plankton communities up to coastal areas may be typical in western boundary systems characterized by a narrow continental shelf. specialized medusae siphonophores tropical Atlantic Ocean South Equatorial Current North Brazil Undercurrent Fernando de Noronha chain Northeast Brazil BRESIL ZONE TROPICALE ATLANTIQUE SUD ZONE EQUATORIALE FERNANDO DE NORONHA ARCHIPEL ROCAS ATOLL 034 43 2 270-287 2021 0142-7873 https://www.documentation.ird.fr/hor/fdi:010082083 10.1093/plankt/fbaa066 0142-7873 [F B010082083] https://www.documentation.ird.fr/hor/fdi:010082083 https://www.documentation.ird.fr/intranet/publi/2021-07/010082083.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-07-02 2025-02-24 fdi:010082083 fre