A Gram-negative, short-rod-shaped and non-motile bacterium, strain 12C11(T), was isolated from an oil-degrading consortium, enriched from the Fugong mangrove sediment, Fujian Province of China. Optimum growth was observed at 25 °C, at pH 7.5 and with 4 % (w/v) NaCl. Comparative 16S rRNA gene sequence analysis demonstrated that it shared highest similarity with members of the genus Algoriphagus (97.5-93.4 %), exhibiting 97.5 % sequence similarity to Algoriphagus ornithinivorans IMSNU 14014(T), followed by Algoriphagus vanfongensis KMM 6241(T) (97.2 %); it shared <96.0 % sequence similarity with other members of the genus. Levels of nucleotide sequence similarity between gyrB (DNA gyrase subunit B) genes of strain 12C11(T) and A. vanfongensis KMM 6241(T), A. ornithinivorans IMSNU 14014(T), Algoriphagus marincola SW-2(T) and Algoriphagus hitonicola 7-UAH(T) were 78.8, 78.6, 75.6 and 77.4 %, respectively. Phylogenetic trees based on these housekeeping genes showed that strain 12C11(T) and other Algoriphagus strains formed a distinct lineage. The dominant fatty acids were iso-C15 : 0 (32.1 %), C16 : 1ω7c/C16 : 1ω6c (11.6 %), iso-C17 : 1 I/anteiso-C17 : 1 B (10.1 %), iso-C17 : 0 3-OH (9.2 %) and iso-C17 : 1ω9c/C16 : 0 10-methyl (7.1 %), which accounted for 70.0 % of the total fatty acids. DNA-DNA hybridization showed that strain 12C11(T) shared low DNA-DNA relatedness with A. vanfongensis KMM 6241(T) and A. ornithinivorans IMSNU 14014(T) (30.7±0.9 and 30.5±1.8 %, respectively). The G+C content of the chromosomal DNA of strain 12C11(T) was 38.4 mol%. The major respiratory quinones were MK-7 (96.0 %) and MK-6 (4.0 %). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, the novel strain most appropriately belongs to the genus Algoriphagus, but can readily be distinguished from known Algoriphagus species. The name Algoriphagus zhangzhouensis sp. nov. is proposed (type strain 12C11(T) = CGMCC 1.11027(T) = MCCC 1F01099(T) = DSM 25035(T)).