Association of a luminous Vibrio sp., taxonomically related to Vibrio harveyi, with Clytia linearis (Thornely, 1900) (Hydrozoa, Cnidaria)

►We report the association between a luminous Vibrio and the hydrozoan Clytia linearis. ►Luminous bacteria were isolated from the surface of C. linearis. ►The characterization of the isolates was performed by phenotypic-genotypic analyses. ►The luminous bacterium on C. linearis here is referred to as Vibrio sp. CL1. ►The observed association has ecological as well as epidemiological significance.