Cultured seabass (Dicentrarchuslabrax L.) and seabream (Sparusaurata L.) are marine species of high economic important especially in Mediterranean aquaculture. Among bacterial diseases of marine cultured and wild fish, vibriosis caused by Vibrio species is one of the most prevalent disease. In the present work, we report the isolation and identification of the V. harveyi and V. alginolyticus, based on biochemical and molecular characterization, from cultured seabass and seabream native to private fish farms at Mathalath-El Diba region, Domitte City at Domitte Governorate, Egypt during summer season. The most prominent clinical signs of diseased fish were hemorrhagic ulceration on the dorsal musculature and caudal peduncle area as well as sever protrusion of the eye outside the orbital cavity. Histological examination of seabass revealed haemorrhages on the liver and nodular formation on different organs |