Pathogeny Study on Tail-rot Disease in Marine Cage-cultured Pesudociaena crocea

[Objective] To find out the pathogen of tail-rot disease in marine cage-cultured Pseudosciaena crocea in Zhoushan.[Methods] The pathogen in the fish suffered from tail-rot disease was isolated.Artificial infection and drug sensitivity test were carried out.[Results] Two bacteria strains(S030901 and S030902) were isolated.Artificial infection showed that the S030901 was high pathogenicity with 100% death rate.And S030902 was almost non-pathogenicity.The S030901 was identified as Vibrio harveyi,and the S030902 as Vibrio alginolyticus because of the bacteria shapes and biochemical characteristics.The drug sensitivity test showed that the S030901 was highly sensitive to 17 antibiotics,and was moderately sensitive to 7 drugs(cefradine etc.),but low sensitive to other 16 drugs(pcnicillin G etc.).[Conclusion] Vibrio harveyi is the main pathogen for the tail-rot disease in marine cage-cultured Pseudosciaena crocea in Zhoushan.