Abstract

A trial of using Bafry D50/500 to control saprolegniosis at a dose of 0.75 ml/L (375 ppm) for 10–12 minutes on 3 successive days as a bath gave good results in the treatment of diseased fish in aquaria. The mortality rate reached 16.7%, without any effect on the health status of treated fish and without any effect on the haematology and blood chemistry of fish treated with Bafry D50/500. Histopathological findings of fish treated with Bafry D50/500: the skin showed an increase of M.M.C. and slight sloughing of the most superficial layer of the epidermis, while the gills showed hyperplasia of the epithelial cells covering the primary lamellae. This indicates that the infected fish were treated with Bafry D50/500.

Materials and Methods

1. Materials
2. Naturally infected fish
3. Fish for experiment
4. Media
5. Chemicals used for treatment
6. Stain

Methods

1. Clinical examination
2. Post-mortem examination
3. Bacteriological examination
4. Mycological examination:
   • Isolation of fungi: This was carried out on naturally infected fish. Samples were taken from fish showing lesions of the skin, eyes, fins, gills, mouth, spleen, liver and kidney, inoculated onto SDA medium plates and incubated at 20 ± 2 °C for 3–4 days; subculture on the same medium was done for purification.
   • Identification of the isolates
   • Biochemical analysis
   • Histopathological examination of infected and treated fish

Results

• Clinical examination
• Post-mortem examination
• Mycological examination

• Histopathological Examination

• Histopathological examination of naturally infected fish
• Histopathological examination of treated fish

Conclusion

The most effective method for controlling and preventing saprolegniosis in the fish ecosystem is a combination of good fish management, such as good water quality and avoiding adverse water temperatures, and Bafry D50/500 used for control at a concentration of 0.75 ml/L (375 ppm) as a bath for 10 minutes.