A Gram-negative, aerobic bacterium, H1-M8(T), was isolated from seashore sand in Korea and then characterized using a polyphasic approach. Cells were short rods (0.7-1.0 x 1.5-2.0 microm) and were motile (each cell having at least one flagellum). Colonies were light-brown, non-pigmented, circular and convex with clear margins. Growth of the strain was observed at 5-35 degrees C, pH 6.0-9.0 and NaCl concentrations up to 8.4 % (w/v). Phylogenetic analysis of the 16S rRNA gene sequence revealed a clear affiliation between the novel strain and members of the genus Jannaschia. The sequence similarities between H1-M8(T) and type strains of the genus Jannaschia ranged from 97.0 to 97.8 %. However, DNA-DNA hybridizations between the isolate and type strains of other related species produced low values (21-38 %). The major isoprenoid quinone was Q-10 and the predominant cellular fatty acids were 18 : 1omega7c (68.2 %) and 18 : 0 (10.5 %). The G+C content of the DNA was 63.6 mol%. On the basis of physiological, biochemical and chemotaxonomic traits and data from the comparative 16S rRNA sequence analysis, strain H1-M8(T) represents a novel species of the genus Jannaschia, for which the name Jannaschia pohangensis sp. nov. is proposed. The type strain is H1-M8(T) (=KACC 11609(T) =DSM 19073(T)).