A psychrophilic bacterium, designated strain HJ039(T), was isolated from a marine sponge collected in the East Sea of Korea (also known as the Sea of Japan). Cells were Gram-negative, motile and rod-shaped (1(.)8-3(.)54 mu m x 0(.)27-0(.)73 mu m). Growth was observed between 5 and 26 degrees C (optimum 15 degrees C), at pH 5(.)0-8(.)5 (optimum pH 6(.)0-6(.)5) and in the presence of 0-6(.)0% NaCl (optimum 2.0%). The 16S rRNA gene sequence of strain HJ039T showed high levels of similarity (93(.)7-95(.)4%) with members of the genus Shewanella, especially with Shewanella gaetbuli TF-27(T) (95(.)2%), Shewanella decolorationis S12(T) (94(.)9%), Shewanella putrefaciens LMG 26268(T) (94(.)6%), Shewanella hafniensis p010(T) (94(.)6%), Shewanella algae ATCC 51192 T (94(.)5%) and Shewanella kaireitica c931(T) (94(.)5%). However, phylogenetic analysis revealed that strain HJ039(T) shared a phyletic line with S. algae and Shewanella amazonensis. The major respiratory quinone was Q-8. The DNA G+C content was 52(.)8 mol%. The major fatty acids were i-13:0(8(.)5%), 15:0 (4(.)2%), i-15:0 (23(.)2%), i-15:1 (7(.)9%), 16:0 (8(.)7%), 16:1 omega 7 (21(.)0%) and 17:1 omega 8 (6(.)4%). From this polyphasic taxonomic evidence, strain HJ039T is considered to represent a novel species of the genus Shewanella, for which the name Shewanella spongiae sp. nov. is proposed. The type strain is HJ039(T) (= KCCM 42304(T) = JCM 13830(T)).