TY - JOUR T1 - Culturable diversity of Arctic phytoplankton during pack ice melting JF - bioRxiv DO - 10.1101/642264 SP - 642264 AU - Catherine GĂ©rikas Ribeiro AU - Adriana Lopes dos Santos AU - Priscillia Gourvil AU - Florence Le Gall AU - Dominique Marie AU - Margot Tragin AU - Ian Probert AU - Daniel Vaulot Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/05/20/642264.abstract N2 - Massive phytoplankton blooms develop at the Arctic ice edge, sometimes extending far under the pack ice. An extensive culturing effort was conducted before and during a phytoplankton bloom in Baffin Bay between April and July 2016. Different isolation strategies were applied, including flow cytometry cell sorting, manual single cell pipetting and serial dilution. Although all three techniques yielded the most common organisms, each technique retrieved specific taxa, highlighting the importance of using several methods to maximize the number and diversity of isolated strains. More than 1,000 cultures were obtained, characterized by 18S rRNA sequencing and optical microscopy and de-replicated to a subset of 276 strains presented in this work. Strains grouped into 57 genotypes defined by 100% 18S rRNA sequence similarity. These genotypes spread across five divisions: Heterokontophyta, Chlorophyta, Cryptophyta, Haptophyta and Dinophyta. Diatoms were the most abundant group (193 strains), mostly represented by the genera Chaetoceros and Attheya. The genera Rhodomonas and Pyramimonas were the most abundant non-diatom nanoplankton strains, while Micromonas polaris dominated the picoplankton. Diversity at the class level was higher during the peak of the bloom. Potentially new species were isolated, in particular within the genera Navicula, Nitzschia, Coscinodiscus, Thalassiosira, Pyramimonas, Mantoniella and Isochrysis.Submitted to: Elementa: Science of the Anthropocene Date: May 17, 2019 ER -