Key Technical Points for Pollution-Free Cage Culture of Bass
1. Culture water area
The culture water area generally requires a water depth of 2 m—2.5m. Half a month before stocking fry, quicklime is spread over the surrounding water area for disinfection.
2. Stocking density and disinfection of fry and fingerlings
The stocking size is 0.5 g/fish—0.6 g/fish, and the stocking density is 100 fish/mu—120 fish/sq m. Before stocking, soak them in 0.5%—1% salt for 3—5 minutes; handle the fry and fingerlings carefully during stocking to avoid injury.
3. Feeding management
1. Feeding training: after bass fry are placed in the cage for 2—3 days, put in a small amount of small trash fish every day. When most of the fish come to the water surface to feed, begin feeding small trash fish 2—3 times a day.
2. Feeding is mainly based on locally caught small trash fish, fed 2—3 times a day.
3. Feeding method: adhere to the “four fixed” principles of fixed quality, fixed quantity, fixed time and fixed place.
4. Water quality management
Keep the water clear, change water frequently and add water frequently, and keep the oxygen content in the water not lower than 3 mg/L.
5. Pond patrol
Persist in pond patrol inspections in the morning, at noon and in the evening, keep track of the feeding situation of the bass at all times, and adjust the feeding amount. Observe the activity of the bass, check the water color, and measure the water temperature. When dead fish are found, scoop them out promptly. When diseased fish are found, send them for examination promptly, identify the condition clearly, and carry out prevention and treatment as early as possible. Keep a pond patrol log.
6. Prevention and control of diseases and insect pests of bass
1. Drug prevention. Persist in regular disinfection of the culture water area, feed disinfection and tool disinfection, with prevention as the main approach and prevention valued more than treatment. Carry out preventive measures early. As a preventive measure, the method of hanging bags of crystal trichlorfon around the cage can be used. During treatment, it is best not to use the method of seining and splashing, because the diseased fish are relatively large in size, and seining will aggravate the skin abrasions on the diseased fish while also causing abrasions on the body surface of normal fish, thereby further aggravating the condition.
2. Isolation of diseased fish. During the culture process, strengthen pond patrol inspections. When diseased fish are found, isolate and raise them promptly, and treat them with drugs.
3. Prescribe medicine according to the symptoms. After the pathogen of bass is found, promptly ask technical personnel to inspect and guide, and prescribe medicine according to the symptoms of the bass.