A Gram-stain-negative, strictly aerobic, non-motile, non-gliding, oxidase-positive, catalase-positive, rod-shaped bacterium, designated strain sw153T, was isolated from surface seawater of the South Pacific Gyre (39° 19' S 139° 48' W) during Integrated Ocean Drilling Program Expedition 329. Growth occurred at 10-42 °C (optimum 28 °C), in the presence of 1-8 % (w/v) NaCl (optimum 2 %) and at pH 6.0-10.0 (optimum pH 7.5-8.5). The major fatty acids (>10 %) were iso-C15:0 and summed feature 3 (C16:1ω6c and/or C16:1ω7c). The major polar lipids comprised phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, phosphatidylglycerol, an unidentified polar lipid and an unidentified phospholipid. The major respiratory quinone was ubiquinone-8 (Q-8). The DNA G+C content of strain sw153T was 44.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed strain sw153T within the genus Marinicella, class Gammaproteobacteria. The most closely related species was Marinicella litoralis KMM 3900T (96.6 % 16S rRNA gene sequence similarity). Based on the polyphasic analyses in this study, strain sw153T is considered to represent a novel species of the genus Marinicella, for which the name Marinicella pacifica sp. nov. is proposed. The type strain is sw153T (=JCM 18208T=CGMCC 1.12181T).