현장(現場)에 있어서 양식(養殖)넙치의 질병대책(疾病對策)

Control Methods of Diseased of Japanese Flounder, Paralichthys olivaceus, used in Fish Farms, in Japan

The author introduces the preventive and therapeutic methods of diseases in Japanese flounder which have been conducted by the Fish Disease Laboratory, the Mikamewan Fishery Cooperative Union, Ehime Prefecture, since 1982. Prevention 1. Addition of a sand substrate in the culture pond was effective to prevent ulcer disease. 2. Bathing in 0.5ppm of copper ion was effective to prevent some parasites. 3. Low stocking density of the fish reduced an incidence of edwardsiellosis or gliding bacterial disease. 4. Removal of the diseased fish prevented thd spread of lyphoeystis. 5. So-called $\pi$-water was effective to prevent the fry from some diseases. 6. Immersion of the juvenile in a sodium nifrusylate solution during transportation was effective to prevent gliding bacterial disease. Therapy 1. Sodium nifrustylate or oxytetracycline was effective to cure gliding bacterial disease. 2. Bathing in formalin(150ppm) or freshwater was effective to cure scuticociliatidosis. 3. Erythromycin was effective to cure $\beta$-hemolytic Streptococcus sp. infection. 4. Bathing in a hydrogen peroxide solution(1.5%) was effective to cure white spot disease.