Abstract: After cultivation at 25℃ in 2216E agar medium, a strain of preponderant bacteria was isolated from the body of Pseudosciaena crocea affected by epidemic septicemia. The Pseudosciaena crocea were collected from Ningdeng City, Fujian Province in July 2000.Artificial infection proved that the bacterium isolated was the pathogen of the disease, the LD₅₀ was 1.0×10⁷ cfu·ml^-1.The isolate was tested for 43 items of morphological, physiological and biochemical characteristics and classified as Vibrio parahaemolyticus.The bacteria were gram negative, curved rods, zymolysis type, with single polar flagellum.Oxidase, indole, lysine and ornithine decarboxylase tests were positive, and negative for arginine dihydrolase, urease, Voges-Proskauer, Kanagawa Phenomenon test. Some of the other characteristics, such as utilization of glucose and mannitol, negative for inositol and sucrose, utilization and production of hydrogen sulfide, sensitivity to 0/129, were also proved.

Key words: Pseudosciaena crocea(Richardson), Vibrio parahaemolyticus, Pathogenicity