A Gram-stain-negative, non-flagellated, non-gliding and rod-shaped bacterial strain, designated GM-5 T , was isolated from seawater from near the Korean peninsula. Strain GM-5T was found to grow optimally at pH 7.0-8.0, at 25 C and in the presence of 2 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain GM-5 T falls within the clade comprising the genus Roseivirga, with which it exhibits 94.8-96.8 % sequence similarity. Strain GM-5 T was found to contain MK-7 as the predominant menaquinone and iso-C 15 : 1 G, iso-C 15 : 0 , and iso-C 17 : 0 3-OH as the major fatty acids. The major polar lipids were identified as phosphatidylethanolamine, an unidentified phospholipid and two unidentified lipids. The DNA G+C content of strain GM-5 T was determined to be 42.3 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain GM-5