A Gram-staining-negative, non-motile, catalase- and oxidasepositive bacterium, designated strain I-15T, was isolated from a crab of the Yellow Sea, Korea. On the basis of a 16S rRNA gene sequence analysis, strain I-15T was shown to belong to Bacteroidetes, related to the genus Aestuariibaculum. Sequence similarity between strain I-15T and the only type strain of the genus Aestuariibaculum, Aestuariibaculum suncheonense SC17T, was 96.7%. Strain I-15T grew at 0.5–6.0% (w/v) NaCl, at 10–42°C and at pH 4.5–8.0. It could hydrolyze starch and Tweens 80. Menaquinone-6 was the only respiratory quinone, and summed features 3 (C16:1 ω7c/C16:1 ω6c) (16.4%), iso-C15:0 (15.6%), and iso-C15:1 G (12.6%) were the major cellular fatty acids. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and two unidentified lipids. The DNA G+C content was 39.0 mol%. Polyphasic data allowed genotypic and phenotypic distinction of strain I-15T from the only validly published Aestuariibaculum species. Therefore, the organism is considered a novel species of the genus Aestuariibaculum, for which the name Aestuariibaculum scopimerae sp. nov. is proposed. The type strain is I-15T (=KCTC 32459T =JCM 19486T).