A Gram-stain-negative, facultatively anaerobic coccobacilli approximately 0.4-0.5×0.5-1.1 µm, non-motile, orange-pigmented bacterial strain, designated am2T, was isolated from the coastal area of Weihai, PR China (121° 57' E, 37° 29' N). The temperature, pH and NaCl ranges for growth were 4-40 °C, pH 6.5-8.5 and 0.0-6.0 % (w/v) NaCl. The results of phylogenetic analyses based on 16S rRNA gene sequences revealed that am2T was phylogenetically related to members of the genus Algoriphagus and was closely related to Algoriphagus boritolerans, Algoriphagus namhaensis and Algoriphagus antarcticus with 96.4, 96.2 and 95.8 % sequence similarities, respectively. The quinone system contained menaquinone MK-7 as the predominant component. The dominant fatty acids were iso-C17 : 1ω9c,iso-C16 : 1H and iso-C15 : 0. The major polar lipids consisted of one phospholipid, phosphatidylethanolamine and six unknown lipids. The DNA G+C content was 40.6 mol%. On the basis of morphological, physiological and molecular properties as well as on phylogenetic distinctiveness, am2T should be placed into the genus Algoriphagus as a novel species, for which the name Algoriphagus marinus sp. nov. is proposed. The type strain is am2T (=KCTC 52549T=MCCC 1H00178T).