A motile, curved to twisted rod-shaped aerobic bacterium, designated strain 04SU4-P(T), was isolated from freshwater collected from the Woopo wetland (Republic of Korea). Cells were observed to be Gram-stain negative, catalase negative and oxidase positive. The major fatty acids (>10 % of the total) were identified as C19:0 ω8c cyclo (24.6 %), C16:0 (24.3 %) and C18:1 ω7c (13.1 %). The DNA G+C content was determined to be 71.5 mol%. The major polar lipids were identified as phosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown aminolipid. The major ubiquinone was determined to be Q-10. A phylogenetic tree based on 16S rRNA gene sequences showed that strain 04SU4-P(T) forms an evolutionary lineage within the genus Dongia and its nearest neighbour is Dongia mobilis LM22(T) (98.0 % sequence similarity). Genomic DNA-DNA hybridization of stain 04SU4-P(T) with D. mobilis LM22(T) showed relatedness of only 34.2 %. The phenotypic characteristics indicate the strain 04SU4-P(T) can be distinguished from the sole member of the genus Dongia. On the basis of the data presented in this study, strain 04SU4-P(T) represents a novel species, for which the name Dongia rigui is proposed. The type strain is 04SU4-P(T) (KCTC 23341(T) = JCM 17521(T)).