• This disease occurs in silver carp, big head carp, grass carp, and common carp.
• This disease was seriously threat to fingerling and big fish.
• This disease can also affect young fish in the pond, and they must be removed.
Bacteria disease
• (Pedomonas dermoalba)
• The causative agent is Pedomonas dermoalba, which is 0.8 to 0.4 microns in size.
Characteristics of the disease
• The fish feed less or stops feeding, and under the dorsal fin near the tail have white spots appear and spread all the way to the tail.
• Fish with the disease swim slowly, with their tails stiffening to the body. Sometimes the tails are torn off. The fish remain still, unable to move. They float silently on the water, then sink to the bottom of the pond and die.
• For unscaled fish, such as catfish, blood vessels are observed on the skin.
• White spots or white tail disease often occurs after collecting the fingerling and big fish, and sometimes occurs spontaneously.
Symptoms of the White spots or white tail disease
Prevention
• Do not collect fish with net on very hot days and when the water temperature is high.
• We must collect fish early in the morning or on a cool day. When catching fish, we must not injure or damage the fish, which can lead to disease.
• (Biomycin Streptomycin)
• Before releasing fish back into the pond, soak the fish in a solution of Biomycin Streptomycin at a concentration of 12.5 ppm for 30 minutes to prevent White spots or white tail disease.
• You can use CuSo4/ 0.5 PPm solution to soak in the pond.
Treatment
• According to Chinese documents, this disease can be treated by soaking sick fish in a mixture of liquid.
- No3Hg ឬ CH3-
- No3Hg or CH3- concentration 2 ppm, soak fish for 120-150 minutes
- Ca(Ocl) ppm
- Chlorine powder Ca(Ocl)2, concentration 1 ppm
Principles of prevention
• Fish are aquatic animals, making it difficult to see their swimming and feeding activities, and even more difficult to diagnose and treat diseases.
• When cattle, pigs, chickens, and ducks are sick, they can be treated by giving them medicine orally or by injecting them, etc. However, fish raised in ponds are very difficult to treat with medicine.
• Therefore, disease prevention for fish is of great importance in fish farming.