A motile, facultative anaerobic, marine bacterial isolate (CAIM 1437T) was obtained from a cultured oyster (Crassostrea gigas) in Sonora, México. The strain was studied by a phylogenetic analysis based on sequences of the 16S rRNA and five housekeeping genes i.e. ftsZ, gapA, pyrH, recA, and topA. Comparison of the almost-complete 16S rRNA gene sequence with those of other type strains of the genus Vibrio showed a close relationship with the type strains of Vibrio orientalis and Vibrio rotiferianus, with similarity values ranging from 98.4 to 98.3%, respectively. MLSA placed this strain within the Orientalis clade. The DNA-DNA hybridization value of strain CAIM 1437T with V. orientalis was 59% and with V. rotiferianus 55%. The DNA G+C content was determined to be 45.6 mol%. Phenotypic characteristics also showed differences with the species analysed. The results presented here support the description of a novel species, for which the name Vibrio crosai sp. nov. is proposed, with CAIM 1437T (=DSM 27145T) as the type strain.