Two novel bacterial strains, designated C5(T) and C9 were isolated from a fish cage at Tongyeong, South Korea and were characterized to determine their taxonomic position. The strains were Gram-negative, non-motile, strictly aerobic and short rod shaped. Growth occurred between 20 and 32 A degrees C (optimum 30 A degrees C) and at pH 6.0-9.0 (optimum pH 8.0) and at 0-10 % NaCl (optimum at 2 % NaCl). Based on the 16S rRNA gene sequence analysis, they were identified as a member of the genus Loktanella that belongs to the phylum Proteobacteria. Strains C5(T) and C9 were analyzed by a polyphasic approach, revealing variations in their phenotypic characters but reciprocal DNA-DNA hybridization values confirmed that they belong to the same species. Phylogenetic analysis of the 16S rRNA gene sequences of closely related species indicated their similarities were below 97 %. The predominant isoprenoid quinone is ubiquinone-10 (Q-10). The major cellular fatty acids were C-16:0, and C-18:1 omega 7c. Major polar lipid contained phosphatidylglycerol (PG), phosphatidycholine (PC), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), unidentified amino lipid (AL) and unidentified lipids (L1-3). Based on phylogenetic and phenotypic data, the isolated strains represent a novel species of the genus Loktanella, for which the name Loktanella aquimaris sp. nov. is proposed. The type strains were C5(T) (=KEMB 3-892(T) = JCM 30382(T)), and a second strain is C9 (=KEMB 3-893 = JCM 30383).