A Gram-negative, strictly aerobic, slightly curved rod-shaped bacterial strain, designated CL-UU02(T), was isolated from coastal seawater off the east coast of Korea. 16S rRNA gene sequence analysis revealed a clear affiliation of this novel strain with the family Rhodospirillaceae. Strain CL-UU02(T) formed a robust cluster with the type strains of species of the genus Rhodovibrio at 16S rRNA gene sequence similarity levels of 89.9-90.4 %. Strain CL-UU02(T) shared no more than 89 % 16S rRNA gene sequence similarity with the type strains of other species in the family Rhodospirillaceae. Strain CL-UU02(T) was able to grow in the presence of 2-6 % sea salts, and grew optimally at 28-30 degrees C and pH 7-8. The DNA G+C content of strain CL-UU02(T) was 66.3 mol%. On the basis of phylogenetic analyses and chemotaxonomic and physiological data, strain CL-UU02(T) is considered to represent a novel species of a new genus in the family Rhodospirillaceae, for which the name Pelagibius litoralis gen. nov., sp. nov. is proposed. The type strain of Pelagibius litoralis is CL-UU02(T) (=KCCM 42323(T)=JCM 15426(T)).