A novel aerobic bacterium, designated strain PIII.02(T), was isolated from a Mediterranean sponge (Axinella polypoides) collected off the Israeli coast near Sdot Yam. The non-motile cells were Gram-staining-negative, oxidase-positive and catalase-positive. The orange pigment of colonies growing on marine agar was neither diffusible nor flexirubin-like. Strain PIII.02(T) grew at 15-35 °C, at pH 6.0-9.0, with 2.0-7.0 % (w/v) NaCl, and with 1.0-8.0 % (w/v) sea salts. The predominant fatty acids were iso-C15 : 0, iso-C16 : 1 H, iso-C16 : 0, C16 : 0, anteiso-C15 : 0 and C16 : 1ω7c. The major respiratory quinone was MK-7. The genomic DNA G+C content of the novel strain was 38.1 mol%. Results from 16S rRNA gene sequence analysis indicated that strain PIII.02(T) was distantly related to established members of the phylum Bacteroidetes. The established species found to be most closely related to the novel strain was Persicobacter diffluens NCIMB 1402(T) (87.6 % 16S rRNA gene sequence similarity). Based on the phenotypic and chemotaxonomic data and the results of the phylogenetic analyses, strain PIII.02(T) represents a novel species of a new genus, for which the name Luteivirga sdotyamensis gen. nov., sp. nov. is proposed. The type strain is PIII.02(T) ( = ATCC BAA-2393(T) = LMG 26723(T)).