Fish Diseases and Management

5.5.2 Ichthyophonus hoferi

This fungus causes an internal infection and is generally chronic and progressive. It is usually detected on necropsy when the characteristic spherical cyst stages are seen microscopically in the smears of granulomatous lesions of the heart, liver, spleen, kidney, skin, and muscle. Preventive measures include removal of infected fish and avoiding feeding raw fish products. Iodophors of varying iodine concentrations are used to prevent mycotic infections of non food-fish eggs, which can be disinfected by a 100 ppm iodine bath for 10-15 min. Formaldehyde up to 2,000 ppm for 15 min, can be used to treat eggs for the control of fungi.