<b>Tara Oceans </b><b>V9-</b><b>18S rDNA metabarcodes</b><b> </b>-<b> </b>We used the global metabarcoding data set generated from the biological samples collected from 146 sampling locations during the <i>Tara</i> Oceans expedition. We extracted ribotypes that were assigned to <i>Minidiscus </i>and <i>Minutocellus </i>from the three depths - surface (SRF), deep chlorophyll maximum (DCM) and mesopelagic (MESO)- within the different size class filters (ranging from 0.8 - 2,000 µm, with the smallest fraction being 0.8 to 5 µm). The taxonomic assignations was done using PR2 reference database which has six reference sequences from <i>Minidiscus</i> <i>trioculatus</i>, 2 from <i>Minidiscus</i> sp., and one is environmental sequence. Relative abundance was calculated with respect to total diatom reads and to total phytosynthetic reads, which comprised reads assigned to major phytoplanktonic groups, namely Bacillariophyta, Chlorophyceae, Cryptophyta, Dictyochophyceae, Dinophyceae, Haptophyta, Mamiellophyceae, Pelagophyceae and Raphidophyceae. Exponentiated Shannon-Weiner H’ diversity index was used as the estimates of diversity at each station. All the analyses were conducted using open source R version 3.3.1.<p><br></p
