title: The Tara Oceans voyage reveals global diversity and distribution patterns of marine planktonic ciliates.
abstract: Illumina reads of the SSU-rDNA-V9 region obtained from the circumglobal Tara Oceans expedition allow the investigation of protistan plankton diversity patterns on a global scale. We analyzed 6,137,350 V9-amplicons from ocean surface waters and the deep chlorophyll maximum, which were taxonomically assigned to the phylum Ciliophora. For open ocean samples global planktonic ciliate diversity is relatively low (ca. 1,300 observed and predicted ciliate OTUs). We found that 17% of all detected ciliate OTUs occurred in all oceanic regions under study. On average, local ciliate OTU richness represented 27% of the global ciliate OTU richness, indicating that a large proportion of ciliates is widely distributed. Yet, more than half of these OTUs shared <90% sequence similarity with reference sequences of described ciliates. While alpha-diversity measures (richness and exp(Shannon H)) are hardly affected by contemporary environmental conditions, species (OTU) turnover and community similarity (β-diversity) across taxonomic groups showed strong correlation to environmental parameters. Logistic regression models predicted significant correlations between the occurrence of specific ciliate genera and individual nutrients, the oceanic carbonate system and temperature. Planktonic ciliates displayed distinct vertical distributions relative to chlorophyll a. In contrast, the Tara Oceans dataset did not reveal any evidence that latitude is structuring ciliate communities.
authors.affiliation: University of Kaiserslautern, Ecology Group, D-67663 Kaiserslautern, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Gimmler
authors.affiliation: University of Kaiserslautern, Financial Mathematics Group, D-67663 Kaiserslautern, Germany.|Fraunhofer Institute for Industrial Mathematics ITWM, D-67663 Kaiserslautern, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Korn
authors.affiliation: CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, F-29680 Roscoff, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, F-29680 Roscoff, France.
authors.forename: Colomban
authors.initials: C
authors.lastname: de Vargas
authors.affiliation: CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, F-29680 Roscoff, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, F-29680 Roscoff, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Audic
authors.affiliation: University of Kaiserslautern, Ecology Group, D-67663 Kaiserslautern, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Stoeck
mesh_terms: D059001:Aquatic Organisms / Q000145:classification / Q000235:genetics / Q000502:physiology*; D044822:Biodiversity; D002734:Chlorophyll / Q000378:metabolism; D014644:Genetic Variation; D005843:Geography; D038622:Internationality; D009792:Oceans and Seas; D010933:Plankton / Q000145:classification / Q000235:genetics / Q000502:physiology*; D018709:Statistics, Nonparametric
chemical_list: D002734:Chlorophyll