|Ocean plankton. Eukaryotic plankton diversity in the sunlit ocean. |
Auteur(s): De vargas Colomban, Audic Stéphane, Henry Nicolas, Decelle Johan, Mahé Frédéric, Logares Ramiro, Lara Enrique, Berney Cédric, Le bescot Noan, Probert Ian, Carmichael Margaux, Poulain Julie, Romac Sarah, Colin Sébastien, Aury Jean-marc, Bittner Lucie, Chaffron Samuel, Dunthorn Micah, Engelen Stefan, Flegontova Olga, Guidi Lionel, Horák Aleš, Jaillon Olivier, Lima-mendez Gipsi, Lukeš Julius, Malviya Shruti, Morard Raphael, Mulot Matthieu, Scalco Eleonora, Hingamp P.
(Article) Publié: Science, vol. 348 p.1261605 (2015)
Marine plankton support global biological and geochemical processes. Surveys of their biodiversity have hitherto been geographically restricted and have not accounted for the full range of plankton size. We assessed eukaryotic diversity from 334 size-fractionated photic-zone plankton communities collected across tropical and temperate oceans during the circumglobal Tara Oceans expedition. We analyzed 18S ribosomal DNA sequences across the intermediate plankton-size spectrum from the smallest unicellular eukaryotes (protists, >0.8 micrometers) to small animals of a few millimeters. Eukaryotic ribosomal diversity saturated at ~150,000 operational taxonomic units, about one-third of which could not be assigned to known eukaryotic groups. Diversity emerged at all taxonomic levels, both within the groups comprising the ~11,200 cataloged morphospecies of eukaryotic plankton and among twice as many other deep-branching lineages of unappreciated importance in plankton ecology studies. Most eukaryotic plankton biodiversity belonged to heterotrophic protistan groups, particularly those known to be parasites or symbiotic hosts.