The present data set provides a tab separated text file compressed in a gzip archive. The file includes metadata for each TaraOceans V9 rDNA OTU including the following fields: md5sum = identifier of the representative (most abundant) sequence of the swarm; cid = identifier of the OTU; ctotab = total abundance of barcodes in this OTU; abundance = total abundance of the representative barcode; sequence = nucleic acid sequence of the representative barcode; pid = percentage identity of the representative barcode to the closest reference sequence from V9_PR2; lineage = taxonomic path assigned to the representative barcode; refs = best hit reference sequence(s) with respect to the representative barcode; taxogroup = high-taxonomic level assignation of the representative barcode; TARA_xxx = number of occurrences of barcodes in this OTU in each of the 1046 samples. The file also includes six categories of functional annotations: (1) chloroplast: yes, presence of permanent chloroplast; no, absence of permanent chloroplast; NA, undetermined. (2) symbiont (small partner): parasite, the species is a parasite; commensal, the species is a commensal; mutualist, the species is a mutualist symbiont, most often a microalgal taxon involved in photosymbiosis; no the species is not involved in a symbiosis as small partner; NA, undetermined. (3) symbiont (host): photo, the host species relies on a mutualistic microalgal photosymbiont to survive (obligatory photosymbiosis); photo_falc, same as photo, but facultative relationship; photo_klep, the host species maintains chloroplasts from microalgal prey(s) to survive; photo_klep_falc, same as photo_klep, but facultative; Nfix, the host species must interact with a mutualistic symbiont providing N2 fixation to survive; Nfix_falc, same as Nfix, but facultative; no, the species is not involved in any mutualistic symbioses; NA, undetermined. (4) silicification; yes, the species has a silicified skeleton; no, it does not; NA, undetermined. (5) calcification; yes, the species has a calcified skeleton; no, it does not; NA, undetermined. (6) strontification; yes, the species has a skeleton made of strontium; no, it does not; NA, undetermined. This table has been generated with the same pipeline as for the OTU table in 10.1126/science.1261605 with the following modifications: a more recent version of swarm has been used (v 2.1.1 with fastidious option) vsearch v2.3.1 replace ggsearch36 for the taxonomic assignation with equivalent options An updated version of the reference database has been used (see 10.5281/zenodo.3768951)