Common Disease Prevention and Treatment Methods for Yellow Catfish Farming
The yellow catfish (Pelteobagrus fulvidraco) is commonly known as ga yu, huang gu, huang la ding, and other names, and is quite popular with consumers because its flesh is delicious and nutritious. In recent years, natural water resources of yellow catfish have sharply declined, and artificial farming of yellow catfish has gradually sprung up in various regions, with some diseases also occurring one after another during the farming process. The yellow catfish is a scaleless fish, and drugs are relatively easy to penetrate into the body through the skin, so its sensitivity to drugs is relatively high, and especially copper sulfate and potassium permanganate must be used with caution. The author's methods for diagnosing and treating common yellow catfish diseases over the past few years are introduced as follows:
1. Gill rot disease
Pathogen: Flavobacterium columnare
Symptoms: The diseased fish has a darkened body color and swims alone away from the group. It eats little or stops eating. There are no abnormalities on the body surface, and the gill filaments are rotted and covered with filth.
Prevention and treatment methods:
1. Do a good job of pond clearing, and when stocking fingerlings, soak them in 2% salt water for 5 minutes.
2. Treatment is mainly by external disinfection, using bromochloro hydantoin at 0.3-0.4×10-6g/m3 or an equal amount of trichloroisocyanuric acid sprinkled over the whole pond, and continuous application 2-3 times can cure it.
2. Fulminant hemorrhagic disease
Pathogen: This disease is caused by bacteria.
Symptoms: The fish body surface is yellowish, mucus increases, the skin of the pharynx is damaged and congested, the abdomen is distended, the anus is red and swollen, the fin bases are congested, the fin rays are ulcerated, and there is ascites in the abdominal cavity. This disease breaks out in high-temperature seasons, is fierce in onset, and spreads rapidly.
Prevention and treatment methods:
1. Stock reasonably, with 2500-3000 fingerlings per 0.067 hectares, frequently add fresh water, and when the water quality is too fertile, promptly use ammonia-reducing drugs (such as "Zhongshui" Jiang An Ning) or "Keen" biological water purifying agent to regulate water quality and remove toxic gases from the pond.
2. When the disease occurs, use dibromohydantoin at 0.3-0.4×10-6g/m3 to sprinkle over the whole pond, for 2 consecutive times; for severe cases, it is still necessary to directly broadcast granular bromine and chlorine disinfectant over the whole pond once.
3. Add Ke Bao Ling or Yu Xue Kang to the feed at an inclusion rate of 4‰-5‰, and feed continuously for 3-5 days. If feeding fish paste and fish chunks, add another 1% salt for a better treatment effect.
3. Enteritis disease
Pathogen: Aeromonas punctata.
Symptoms: The fish swims alone, the abdomen is distended, the anus is red and swollen, and when the abdomen is lightly pressed, yellow mucus flows out, and the esophagus and intestines are congested and inflamed.
Prevention and treatment methods:
1. Thoroughly clear the pond, and when the fingerlings are put into the pond, soak them in 2% salt. Do not feed moldy food; soak fresh live animal feed in 2%-3% salt water or add 1% salt to the feed.
2. When the disease occurs, external disinfection is the same as for fulminant hemorrhagic disease. Oral administration: add Chang Jun Ning and allicin to the feed at inclusion rates of 5‰-7‰ and 1‰-2‰ respectively, and feed continuously for 5-7 days.
4. Ichthyophthiriasis
Pathogen: Ichthyophthirius multifiliis.
Symptoms: On the skin, fin rays, and gills of the diseased fish, white small dot-like cysts can be seen with the naked eye. The diseased fish responds slowly or floats on the water surface. Yellow catfish are susceptible to Ichthyophthirius multifiliis, and fulminant death occurs after the disease develops.
Prevention and treatment methods:
1. Thoroughly clear the pond with quicklime, soak the fingerlings in drugs before putting them into the pond, and stock reasonably. During the epidemic period of Ichthyophthirius multifiliis, add 2‰ of oral insecticide Jing II to the feed once every half month, and feed continuously for 3 days.
2. When the disease occurs, sprinkle formalin over the whole pond at 25-30×10-6g/m3, once every other day, with external disinfection more than 3 times. Orally administer Mie Chong Jing II at an inclusion rate of 4‰-5‰, and feed continuously for 5-7 days.
3. Boil chili powder and dried ginger for half an hour and then sprinkle over the whole pond; the amount used is 0.5 kg chili powder and 0.2 kg dried ginger per 0.067 hectares of water 1 m deep.
5. Protozoan diseases
Pathogen: Mainly Chilodonella and Trichodina, which mainly harm fry and fingerlings.
Symptoms: The fin rays and gills of the diseased fish have increased mucus, the fish responds slowly, with the head down and tail up or lying on its side, and in severe infections the diseased fish shows running-horse behavior.
Prevention and treatment methods:
1. Thoroughly clear and disinfect the pond with quicklime.
2. For fry and fingerlings, sprinkle a mixture of 1-2×10-6g/m3 copper sulfate and ferrous sulfate over the whole pond; for severe cases, use it again the next day.
6. Nutritional diseases
Cause: Caused by nutritional imbalance in the feed formula, deterioration of raw materials, or insufficient essential amino acids and energy in the protein, etc.
Symptoms: The liver and gallbladder of the diseased fish are enlarged, the liver is yellow and the gallbladder is black, and the larger individuals die first.
Prevention and treatment methods: Improve the formula, raise feed quality, and make the crude protein content in the feed reach more than 35%. Appropriate amounts of vitamins and trace elements must be added to the feed, and special additives are even better if available. Long-term addition of bioactive substances to the feed can greatly improve the body immunity and growth speed of yellow catfish.
In the process of using drugs to prevent and treat yellow catfish diseases, one must be careful and cautious, strictly control the amount used; generally speaking, the drug concentration used is lower than for other scaled fish, and within 2-3 hours after medication, a specially assigned person is needed to observe, so as to ensure nothing goes wrong