A Gram-negative, aerobic, motile and slightly curved rod-shaped bacterium (BFLP-8(T)) was isolated from cutaneous mucus of wild long-snouted seahorses (Hippocampus guttulatus) captured in northwest Spain (Toralla, Galicia). Strain BFLP-8(T) grew at 10-35 °C and pH 5-9 (optimally at 25 °C and pH 7.0) and with 1-6 % (w/v) NaCl (optimally with 2 % NaCl). The predominant respiratory quinone (90 %) was ubiquinone with ten isoprene units (Q-10) and the major fatty acids identified were C(18:1) ω7c (54.8 % of the total), C(19:0) cyclo ω8c (11.6 %), C(16:0) (9.5 %), C(18:1) 2-OH (7.1 %) and C(16:1) ω11c (6.7 %). The G+C content of the DNA was 57.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BFLP-8(T) formed a distinct clade within the family Sneathiellaceae but is not specifically associated with any species in the family. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain BFLP-8(T) represents a novel species within a new genus, for which the name Oceanibacterium hippocampi gen. nov., sp. nov. is proposed. The type strain is BFLP-8(T) (=CECT 7691(T) = DSM 23444(T)).