A Gram-negative, rod-shaped, strictly aerobic bacterium, designated strain CL-SK30(T), was isolated from a culture of the marine ciliate Myrionecta rubra. 16S rRNA gene sequence analysis revealed that strain CL-SK30(T) was most closely related to Cucumibacter marinus (92.0 % similarity) and next to the type strains of species of the genus Devosia (89.8-91.3 % similarities) in the family Hyphomicrobiaceae. Phylogenetic analyses of the 16S rRNA gene sequences showed that strain CL-SK30(T) formed a robust clade together with C. marinus, but the sequence divergence value of 8 % between them indicated that the novel bacterium represented a distinct lineage. Strain CL-SK30(T) grew optimally in the presence of 2-5 % sea salts at 30-35 degrees C and pH 7.2-8.0. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, two unidentified glycolipids, an unidentified phospholipid and an unidentified lipid. Ubiquinone 10 was the major quinone. The DNA G+C content was 52.7 mol%. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain CL-SK30(T) represents a novel genus and species of the family Hyphomicrobiaceae, for which the name Maritalea myrionectae gen. nov., sp. nov. is proposed. The type strain is CL-SK30(T) (=KCCM 90060(T)=DSM 19524(T)).