Twenty-two isolates originating from the gut of healthy cultured turbot larvae in Norway were investigated using a polyphasic approach. Amplified fragment length polymorphism fingerprinting analysis showed that the isolates have typical patterns and form two main groups. Phylogenetic analysis revealed that the isolates belong to the gamma-Proteobacteria, with Vibrio hollisae as their closest neighbour. DNA-DNA hybridization, chemotaxonomic and phenotypic analyses further proved that these isolates represent a tight novel taxon that differs from currently described species in the family Vibrionaceae. It is proposed that these novel isolates be accommodated in a new genus, Enterovibrio gen. nov., with Enterovibrio norvegicus sp. nov. as the type species. Isolates were motile by a polar flagellum, positive for oxidase, catalase, arginine dihydrolase and beta-galactosidase, but negative for the Voges-Proskauer reaction. They produced indole, did not reduce nitrate and were resistant to the vibriostatic agent O/129. The DNA G+C content of E. norvegicus was 47.1-47.9 mol%. The type strain is E. norvegicus LMG 19839(T) (= CAIM 430(T)).