Vibrios are ubiquitous in the marine environment, some of which are opportunistic pathogens, while several others cause serious pathogenic conditions. They are among the bacterial pathogens that top the list of pathogens which lead to economic loss in aquaculture. Although the occurrence of bacterial diseases in marine aquaria is not well documented, disease conditions characteristic of bacterial pathogens were noticed in the captive fishes maintained in the marine aquarium functioning under Vizhinjam Research Centre of Central Marine Fisheries Research Institute (CMFRI). In view of the importance of supply of healthy organisms for commercial aquarium trade, attempts were made to isolate and identify bacterial pathogens from diseased and moribund fishes of the said aquarium. Three species of Vibrio such as Vibrio furnissi, Vibrio fluvialis and Vibrio mediterranei from the commercially important marine ornamental fishes–Acanthurus sp. (surgeon fish), Amphiprion sebae (sebae clown fish), Heniochus acuminatus (banner fish) and Chaetodon auriga (butterfly fish). Among these, V. mediterranei is a comparatively lesser demonstrated species. Biochemical characterization of these isolates was carried out for  differentiation from other species of Vibrio. Previous reports of occurrence of the species are from corals and associated ecosystems. The usefulness of this species in marine culture systems as a potential probiont needs to be investigated. 

Ornamental fish, Vibrio, bacterial isolate, coral, biochemical characterization, probiont