A novel strictly aerobic, heterotrophic, pink-pigmented, non-motile, Gram-negative, oxidase-, catalase-, beta-galactosidase- and alkaline phosphatase-positive marine bacterium, designated strain KMM 6058(T), was isolated from the sea urchin Strongylocentrotus intermedius and studied using a polyphasic taxonomic approach. The G+C content of the DNA of the isolate was 41.3 mol%. The predominant fatty acids were i15:1, i15:0, a15:0 and i17:0 3-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 6058(T) formed a monophyletic clade with Roseivirga ehrenbergii, with 99% similarity. On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, the novel bacterium should be assigned to the genus Roseivirga as Roseivirga echinicomitans sp. nov. The type strain is KMM 6058(T) (=KCTC 12370(T)=LMG 22587(T)).