Natural physiologically active substances efficacious against fish diseases and fish feeds containing the same

摘要

The invention intends to provide a natural physiologically active material effective on fish diseases such as virus diseases, bacterial diseases and parasitic diseases when fed to fish by oral administration, and fish food containing the material. The natural physiologically active material of the invention contains at least one of fatty acids having carbon number 6 to 12 and a material having a vitamin C activity, as required, and effectively acts on the fish diseases. The fish diseases are parasitic diseases, bacterial infections and parasitic infections. At least one of the fatty acids having carbon number 6 to 12 is capric acid, caprylic acid or pelargonic acid.