Holopelagic Annelida from the Atlantic sector of the Southern Ocean and adjacent South Atlantic with descriptions of three new species

Pelagic polychaetes were collected in the Bransfield Strait, the Weddell Sea, and near the South Orkney Islands area in the austral summer of 2022 during the 87^th cruise of the R/V Akademik Mstislav Keldysh. The collected material was studied using morphological, taxonomic, and molecular methods; 18S and D1 regions of 28S genes were used as molecular markers. In total, 17 species were recognized in the studied material, including Alciopini (2), Lopadorrhynchidae (4), Iospilidae (1), Typhloscolecidae (6), and Tomopteridae (4). We clarified relationships between Vanadis antarctica McIntosh, 1885, and V. longissima (Levinsen, 1885). One new typhloscolecid Typhloscolex keldyshi sp. nov. and two new species of Lopadorrhynchidae Pelagobia albertych sp. nov. and Pelagobia torquata sp. nov. have been described. Also, we propose to restore Pelagobia viguieri Gravier, 1911, based on molecular data.