A novel Gram-positive bacterium, designated Kis4-28(T), was isolated from the intestinal tract of a fish, and its taxonomic position was investigated by a polyphasic approach. The sample was collected from the coast of Tokyo Bay, Japan. Cells of strain Kis4-28(T) were rod-shaped, non-motile and non-sporulating. The peptidoglycan type of the isolate was A4alpha; lysine was the diagnostic diamino acid. The only menaquinone detected was MK-8(H(4)), and the major fatty acids were anteiso-C(15 : 0) and C(16 : 0). Galactose was detected as a major cell-wall sugar. The polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content was 70.7 mol%. 16S rRNA gene sequence analysis revealed that strain Kis4-28(T) and the type strain of Salana multivorans formed a monophyletic cluster with a 16S rRNA gene sequence similarity of 96.2 %. Strain Kis4-28(T) was clearly distinguishable from the genus Salana in terms of its chemotaxonomic characteristics. On the basis of the genotypic and phenotypic characteristics, a new genus and species is proposed for strain Kis4-28(T), with the name Serinibacter salmoneus gen. nov., sp. nov. The type strain of Serinibacter salmoneus is Kis4-28(T) (=NBRC 104924(T) =DSM 21801(T)). In addition, on the basis of 16S rRNA gene sequence analysis of the genus Serinibacter and related genera, emended descriptions of the families Beutenbergiaceae and Bogoriellaceae are proposed to accommodate the genera Beutenbergia, Salana and Serinibacter, and the genera Bogoriella and Georgenia, respectively.