A novel blush-red-pigmented, Gram-stain-negative, gliding, aerobic and rod- or oval-shaped bacterium, designated strain 12N15(T), was isolated from sediment sampled at a marine saltern located in Wendeng, China (36 degrees 59' 56.49 '' N, 122 degrees 1' 38.84 '' E). Growth was observed at 10-40 degrees C (optimum, 28 degrees C), in 1.0-12.0 % NaCl (2.0-5.0 %, w/v) and at pH 6.0-9.5 (pH 7.0). The respiratory quinones were determined to be 0-10 and major fatty acids were C-18:1 omega 7c and C-18:0. The polar lipids profile of strain 12N15(T) included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminolipid, phosphatidylcholine, one lipid and three phospholipids. The genomic DNA G+C content was 69.6 mol%. Phylogenetic analyses based on the 16S rRNA gene showed that the strain 12N15(T)was affiliated within the genus Jannaschia, and was most closely related to Jannaschia seohaensis KCTC 22172(T). The average amino acid identity and percentage of conserved protein values between strain 12N15(T) and the type strain of the type species, Jannaschia helgolandensis DSM 14858(T), were 70.2 % and 64.1 %, respectively. The average nucleotide identity value between strain 12N15(T) and J.annaschia seohaensis KCTC 22172(T)- was 81.9 %. The phenotypic, phylogenetic and genomic analyses supported the hypothesis that strain 12N15(T) represents a novel species of the genus Jannaschia, for which the name Jannaschia formosa sp. nov. is proposed. The type strain is 12N15(T) (=MCCC 1H00325(T) =KCTC 62582(T)).