Functional repertoire convergence of distantly related eukaryotic plankton lineages abundant in the sunlit ocean

Marine planktonic eukaryotes play critical roles in global biogeochemical cycles and climate. However, their poor representation in culture collections limits our understanding of the evolutionary history and genomic underpinnings of planktonic ecosystems. Here, we used 280 billion Tara Oceans metagenomic reads from polar, temperate, and tropical sunlit oceans to reconstruct and manually curate more than 700 abundant and widespread eukaryotic environmental genomes ranging from 10 Mbp to 1.3 Gbp. This genomic resource covers a wide range of poorly characterized eukaryotic lineages that complement long-standing contributions from culture collections while better representing plankton in the upper layer of the oceans. We performed the first, to our knowledge, comprehensive genome-wide functional classification of abundant unicellular eukaryotic plankton, revealing four major groups connecting distantly related lineages. Neither trophic modes of plankton nor its vertical evolutionary history could completely explain the functional repertoire convergence of major eukaryotic lineages that coexisted within oceanic currents for millions of years

The 'Pseudorhabdosynochus cupatus group' (Monogenea : Diplectanidae) on Epinephelus fasciatus, E-howlandi, E-rivulatus and E-merra (Perciformes : Serranidae) off New Caledonia, with descriptions of Pseudorhabdosynochus cyathus n. sp and P-calathus n. sp

Pseudorhabdosynochus cupatus (Young, 1969) is characterised by small lamellosquamodiscs made up of central telescopic rings and peripheral rows of rodlets, and a sclerotised vagina in the shape of a thin-walled coiled tube with three accessory chambers. Two new species of Pseudorhabdosynochus are herein described from epinepheline fish off New Caledonia, South Pacific, and are considered part of the 'P. cupatus group'. P. cyathus n. sp. from Epinephelus howlandi has lamellosquamodiscs made up of four telescopic rings and four rows of separate rodlets; there are dorsal tegumental scales. This species was found only in young hosts; older hosts harbour P. venus Hinsinger and Justine, 2006. P. calathus n. sp. from Epinephelus rivulatus has lamellosquamodiscs made up of four telescopic rings and five rows of separate rodlets; the tegument is smooth. The three species, P. cupatus, P. calathus and P. cyathus, are strictly species specific; although morphologically very similar, they can be distinguished by features of the tegumental scales and measurements of the vagina and haptoral hard parts. P. melanesiensis (Laird, 1958) from E. merra is close to the 'P. cupatus group' according to the morphology of its sclerotised vagina but is distinguished by its squamodiscs which lack telescopic rings. Rare specimens found in E.merra are tentatively attributed to P. coioidesis Bu et al., 1999. A paratype of P. coioidesis is figured for comparison. E. merra, E. fasciatus, E. rivulatus and E. howlandi each have a Pseudorhabdosynochus species of the P. cupatus lineage: these are the dominant species in each host. In addition, E. merra, E. fasciatus and E. howlandi harbour a rare species of Pseudorhabdosynochus, respectively P. cf. coioidesis, P. caledonicus Justine, 2005 and P. venus; these rare species are morphologically unrelated to each other and to the 'P. cupatus group'

The Phylogeny and Biogeographic History of Ashes (Fraxinus, Oleaceae) Highlight the Roles of Migration and Vicariance in the Diversification of Temperate Trees

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