A heterotrophic marine bacterium, designated strain KTSW-6(T), was isolated from the reef-building coral Stylophora pistillata in Kenting, Taiwan. Cells of strain KTSW-6(T) were Gram-stain-negative, facultatively anaerobic, halophilic, non-motile rods surrounded by a thick glycocalyx-like coat and forming creamy white colonies. Growth occurred at 15-37 �XC (optimum, 25-30 �XC), at pH 7.0-9.0 (optimum, pH 7.5-8.0) and with 0.5-7 % NaCl (optimum, 3-4 %). Polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and three uncharacterized phospholipids (PL1-PL3). The respiratory quinones of strain KTSW-6(T) were Q-8 (62 %) and Q-7 (38 %). Major cellular fatty acids were summed feature 3 (C16 : 1�s7c and/or C16 : 1�s6c, 29.6 %), C18 : 1�s7c (27.6 %) and C16 : 0 (19.5 %). The major cellular hydroxy fatty acid was C10 : 0 3-OH. The DNA G+C content of strain KTSW-6(T) was 48.6 mol%. 16S rRNA gene sequence analysis indicated that strain KTSW-6(T) belongs to the family Oceanospirillaceae of the order Oceanospirillales, class Gammaproteobacteria. Strain KTSW-6(T) shared 92.7 % 16S rRNA gene sequence similarity with Neptuniibacter caesariensis MED92(T) and 92.0 % with Neptunomonas naphthovorans NAG-2N-126(T). On the basis of the genotypic and phenotypic data, strain KTSW-6(T) represents a novel species of a new genus of the Oceanospirillaceae, for which the name Corallomonas stylophorae gen. nov., sp. nov. is proposed. The type strain of Corallomonas stylophorae is KTSW-6(T) (= BCRC 80176(T) = LMG 25553(T)).