What are the control methods for the main diseases of yellow catfish?
The yellow catfish is an important freshwater economic fish in China. China has a history of more than ten years of farming yellow catfish, and it is deeply favored by consumers for its delicious taste. As market demand continues to grow, its farming area and density are also constantly expanding, but at the same time this has brought about a high incidence and frequent occurrence of diseases, seriously affecting farming output and the economic returns of farmers. So what diseases will yellow catfish suffer from during farming? Let's take a look at the detailed introduction from Qinnong Web below.
1. Saprolegniasis
Saprolegniasis is caused by saprolegnia fungi infecting and parasitizing the fish body. The saprolegnia fungi reproduce in the water body. When the yellow catfish suffers external injuries during farming, the saprolegnia fungi will take the opportunity to invade. They parasitize the external wounds of the fish body and continuously reproduce and grow. At the beginning of parasitism they are invisible to the naked eye. As time goes on, the hyphae begin to continuously grow inward and outward, spreading and diffusing, forming white-gray cotton-like matter. When the disease occurs, the sick fish swim restlessly, behave abnormally, and reduce their food intake, eventually dying from complete loss of appetite and gradual emaciation.
Control method: Before releasing the fry, first use quicklime powder to thoroughly disinfect the pond in time, to reduce pathogens and lower the farming density, prevent the fish from rubbing against each other while swimming and causing external injuries, and also be careful during stocking and harvesting. Disinfect regularly and improve water quality. When the disease occurs, sprinkle Shuimeisuke over the whole pond once a day for three consecutive days to cure it.
2. Enteritis disease
Enteritis disease is a bacterial infectious disease caused by infection with Aeromonas punctata. The main reason is that the feed given is not fresh and has become moldy and spoiled. When the disease occurs, the sick fish has a swollen abdomen and red and swollen anus, and yellow mucus flows out when gently pressed. Dissecting the dead fish will reveal congestion and inflammation in the stomach and intestinal areas; in severe cases the entire intestine is inflamed and light red, with blood and pus filling the intestinal tract. After the disease occurs, the sick fish leave the group and move alone, swim slowly, and weaken in appetite until death.
Control method: Similarly, continue to thoroughly disinfect the pond to reduce pathogenic bacteria. The feed given must be fresh; do not feed spoiled or moldy feed. Live bait should be disinfected before feeding, and leftover bait after feeding should be cleaned up in time. Especially in summer, also pay attention to controlling water temperature, because the epidemic period of this disease is when the water temperature is 25-30 degrees. After the disease occurs, sprinkle dibromohydantoin over the whole pond, then add some table salt to the feed.
3. Hemorrhagic edema disease
Hemorrhagic edema disease is also a bacterial disease and is a common disease during yellow catfish farming. When the disease occurs, the body surface of the sick fish turns yellow, mucus increases, the abdomen swells, and the anus becomes red, swollen and everted. In addition, congestion and edema appear on the chest, fins, and back. When the condition is severe, appetite is completely lost, a large amount of blood water or yellow gelatinous matter accumulates in the abdominal cavity, and there is a large amount of pus in the stomach and intestines, with a high mortality rate.
Control method: Do a good job in water quality management, maintain a good farming environment, pay attention to the dissolved oxygen level of the water body and the farming density, and disinfect regularly. When the disease occurs, first disinfect the water quality, then add an appropriate amount of Fuerkang to the feed and an appropriate amount of table salt to the meat bait for 5-7 consecutive days to cure it.
4. Trichodiniasis
Trichodiniasis is a parasitic disease and is a major parasitic disease during fish farming. After infection, the sick fish become restless, lethargic, and reduce their food intake. In severe cases, they continuously swim along the edge of the farming pond. Under a microscope, a large number of trichodina can be found on the body surface and gills of the sick fish. It mainly occurs in late spring and early autumn when the climate is cool.
Control method: Strengthen water quality management. After the disease occurs, sprinkle a mixture of 0.7 g copper sulfate and ferrous sulfate per cubic meter over the whole pond once every three days for 2-3 consecutive times to recover.
The above are the control methods for the main diseases of yellow catfish brought to you by Qinnong Web. We hope it can help you. To learn more about fish farming knowledge, please stay tuned to Qinnong Web.