Shewanella psychromarinicola sp. nov., a psychrophilic bacterium isolated from pelagic sediment of the Ross Sea (Antarctica), and reclassification of Shewanella arctica Kim et al. 2012 as a later heterotypic synonym of Shewanella frigidimarina Bowman et al. 1997 Hwang, Yeon Ju and Jang, Gwang Il and Cho, Byung Cheol and Lee, Jae Il and Hwang, Chung Yeon,, 69, 2415-2423 (2019), doi = https://doi.org/10.1099/ijsem.0.003490, publicationName = Microbiology Society, issn = 1466-5026, abstract= Two Gram-stain-negative, rod-shaped, facultatively anaerobic, iron-reducing bacterial strains, designated M2T and R106, were isolated from pelagic surface-sediment of the Ross Sea, Antarctica. The 16S rRNA gene sequence analysis revealed that strains M2T and R106 were affiliated to the genus Shewanella and formed a distinct subline in a robust clade encompassing Shewanella vesiculosa , Shewanella livingstonensis , Shewanella arctica and Shewanella frigidimarina with a range of sequence similarities of 98.1–98.9 %. Overall genome relatedness indices indicated that M2T and R106 represented a single genomic species, which was clearly distinguishable from the phylogenetically close relatives with lower values of species delineation thresholds. Cells of M2T grew optimally at 10–15 °C and pH 6.5 in the presence of 3.0–4.0 % (w/v) sea salts. The polar lipids of M2T comprised phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid and an unidentified phospholipid. Quinones were Q-7, Q-8, MK-7 and MMK-7. The major cellular fatty acids (>10 %) were C16 : 1ω7c and/or C16 : 1ω6c, C16 : 0 and C17 : 1ω8c. The DNA G+C content was 42.2 mol%. On the basis of the phenotypic, phylogenetic, genomic and chemotaxonomic features, we propose the name Shewanella psychromarinicola sp. nov. with the type strain M2T (=KCCM 43257T =JCM 32090T) and the reclassification of S. arctica as a later heterotypic synonym of S. frigidimarina ., language=, type=