A marine bacterial strain, KMD 002T, was isolated from an Amur starfish, Asterias amurensis, collected in the East Sea of Korea. Strain KMD 002T was a Gram-negative, beige-pigmented, rod-shaped bacterium. The strain was capable of growth at relatively low temperatures (4-25 degrees C) and over a broad pH range (pH 4.0-10.0). The major fatty acids were C16:1omega7c and/or iso-C15:0 2-OH and C16:0 and the predominant isoprenoid quinone was Q-8. The DNA G+C content of strain KMD 002T was 40.3 mol%. Phylogenetic analysis using 16S rRNA gene sequences revealed that strain KMD 002T belonged to the genus Colwellia. However, various phenotypic properties as well as low 16S rRNA gene sequence similarities to members of the genus Colwellia (94.1-96.7%) suggested that strain KMD 002T is a representative of a novel species, for which the name Colwellia asteriadis sp. nov. is proposed. The type strain is KMD 002T (=KCCM 90077T =JCM 15608T).