A marine bacterium, DOKDO 007(T), was isolated from the rhizosphere of the marine alga Ecklonia kurome collected from Dokdo Island, Korea, in October 2004. The strain produced orange-coloured colonies on marine agar 2216. 16S rRNA gene sequence analysis indicated that the novel isolate belonged to the family Flavobacteriaceae and showed relatively high sequence similarities with members of the genus Muricauda (92.0-94.0 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that the novel isolate shared a lineage with members of the genera Muricauda and Costertonia. Cells were aerobic, Gram-negative rods producing non-diffusible carotenoid pigments. In contrast to all other members of the family Flavobacteriaceae, cells of DOKDO 007(T) were motile by means of a polar flagellum. Optimal growth occurred in the presence of 3.5-4 % (w/v) sea salts (corresponding to 2.7-3.1 % NaCl), at pH 8 and at temperatures of 26-29 degrees C. The novel strain required Ca(2+) ions in addition to NaCl for growth. The dominant fatty acids were iso-15 : 0, iso-15 : 1omega10c and 10-methyl-16 : 0. The major respiratory quinone was MK-6. The DNA G+C content was 56.3 mol%, an unusually high value for members of the family Flavobacteriaceae. On the basis of these polyphasic taxonomic data, strain DOKDO 007(T) should be classified as representing a new genus and novel species in the family Flavobacteriaceae, for which the name Flagellimonas eckloniae gen. nov., sp. nov. is proposed. The type strain is DOKDO 007(T) (=KCCM 42307(T)=JCM 13831(T)).