Gravier-Bonnet N. auteur aut IRD Boissin E. auteur aut IRD Hoarau L. auteur aut IRD Plantard P. auteur aut IRD Loisil C. auteur aut IRD Ory D. auteur aut IRD Mulochau T. auteur aut IRD Chabanet Pascale auteur aut IRD Adjeroud Mehdi auteur aut IRD Bourmaud C. auteur aut IRD Rouzé H. auteur aut IRD text journalArticle eng text/pdf born digital access This study explored the unknown biodiversity of mesophotic coral ecosystems (MCEs) in Reunion Island, located in the Southwestern Indian Ocean. MCEs are still largely unexplored whereas they are assumed to shelter a rich and unique biodiversity. As they might likely serve as a source for recolonization after disturbances in shallower reefs, their study is urgently needed. This work focused on an understudied large group of structural and functional ecological importance in reef benthic communities, the hydroids. Performing only 8 deep dives with closed-circuit rebreathers, we recorded 74 species between 65 and 93 m among which 11 species and 3 genera are likely new to science. Furthermore, the explorations made in contrasted geographical zones around the island suggest particular eco-physiological traits for some species: specialized vs. widely tolerant. This preliminary report only shows the tip of the iceberg and opens an avenue for exploration and understanding of such extraordinary biodiversity at such depths. specialized Hydrozoan Tropical Low-light environment Species discovery Citizen science Deep dives REUNION OCEAN INDIEN 036 034 52 4 38 [9 p.] 2022 1867-1616 https://www.documentation.ird.fr/hor/fdi:010085878 10.1007/s12526-022-01274-4 1867-1616 [F B010085878] https://www.documentation.ird.fr/hor/fdi:010085878 https://www.documentation.ird.fr/intranet/publi/2022-09/010085878.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2022-09-28 2025-02-24 fdi:010085878 fre