Experience of culturing perch in pond

1. Clear the pond and cultivate water

The ponds used for raising perch had better go through dry ponds, desilting and sun exposure, especially the old ponds that have been farmed for many years. Sterilize once half a month before seedling release, apply 50kg quicklime per mu or use 20PPM bleach with appropriate amount of pool water for disinfection. If there is no dry pond exposure, but also use 30 kilograms of tea bran per mu to break and soak the whole pond to thoroughly remove the ferocious miscellaneous fish left behind. Fresh water is added into the disinfected pond through the filter net, and 3 kg compound fertilizer per mu is applied to cultivate plankton, and the water quality is light green or light brown.

2. Seedling density

The number of fish species cultivated in the middle has reached 10 cm, and it is better to release 2500 fish per mu, and the yield per mu can reach 1200 MUE 1500 kg during the 300-day culture period. If the seedling is too dense, the pond is prone to aging and fish disease, so it is difficult to carry out sustainable production. Because there are many baits in high-density culture, and sea bass seldom look for the leftover bait at the bottom of the pond, 100 crucian carp and 30 silver carp and silver carp should be put per mu to reduce water pollution and increase culture efficiency.

3. Overeating of bait bass

Proper control of the amount of feeding is beneficial to reduce the cost, reduce the occurrence of gastrointestinal diseases and water pollution. Bait to achieve timing, fixed point, quantitative, generally feed two meals a day, respectively at 7: 00 in the morning and 4: 6 in the afternoon, daily feeding is about 5% of the weight of the fish. To adhere to the habit of domestication, build a bait bridge in the pond, each time bait hit the bait bridge or splashing pond water, inviting the fish to swim to grab food, which is helpful to observe the eating and health status of the fish, and facilitate the adoption of contingency measures. The sea bass grabs the feed suspended in the water and no longer eats after sinking, so the small miscellaneous fish should be fed patiently and slowly, and the pellet feed should be fed with floating feed.

4. Water quality management

In the high-yield culture of sea bass, that is, high-density culture, it is very important to maintain fresh water quality and sufficient dissolved oxygen. The main methods are as follows: change water frequently, especially in the middle and later stages, the daily water exchange rate should reach more than 30%. In order to increase oxygen frequently, the aerator can be started properly in the fry stage, and the frequency of starting the aerator becomes more and more frequent with the growth of the fish, especially in the high temperature weather and the later stage of culture, part of the aerator can be started at night, and all aerators should be started during the day. keep the dissolved oxygen content of pond water above 5 mg / L With the application of biological agents, high-density culture brings a large number of residual bait and excreta at the bottom of the pond, the decomposition concentration of harmful substances is high, and a large amount of oxygen in the water is consumed, especially in high temperature weather, which is an important cause of fish disease. appropriate application of biological agents to beneficial bacteria to remove ammonia nitrogen and nitrite in the water to maintain good water quality.

Disease prevention and cure

1. Ammonia nitrogen poisoning in high temperature weather, the ammonia nitrogen in the water is high, and even nitrite is produced, resulting in anoxia poisoning and death of perch. Main symptoms: fish swimming restlessly in the whole pond, running up and down, fin hyperemia, Gill dark red. Prevention and control methods: immediately inject new water, release old water, pay attention to use boards to block the water when injecting water, so as not to directly wash up the dirt at the bottom of the pond and accelerate the death of fish; apply fluorite powder (substrate treatment agent) 10kg per mu to neutralize ammonia nitrogen in the water; pay attention to the prevention with biological agents before the disease.

2. Enteritis diseased fish have low appetite, abdominal swelling, red and swollen anus, light pressure and yellow mucus outflow, which can occur all year round. The precaution is not to feed spoiled fish. Treatment: every 100 kg of surimi mixed with 300 grams of furosulfonate mixture, continuous administration of 3 Mel for 5 days.

3. Gill rot disease is easy to break out and has a high mortality. Main symptoms: black body color, especially the head, slow swimming, slow response to external stimuli, dyspnea, loss of appetite, increased Gill mucus, Gill filament swelling, terminal erosion, weight loss, leaving the group, and finally death. Treatment: every 100 kilograms of fish was fed continuously for 3 days with 8 grams of compound sulfamethoxazole and 6 grams of chloramphenicol 4 per day.

4. Rotifer, oblique tube worm and polycondensed disease mostly occur in the body surface and Gill filaments of fish in the middle breeding stage. The symptoms are emaciation, blackening and erosion of the mouth, which occur all the year round. In prevention, a large amount of water exchange is used to improve the water quality. The mixture of 0.7-1ppm cupric sulfate and ferrous sulfate (5:2) can be used to sprinkle evenly throughout the pond, or 20-25ppm formalin can be used to sprinkle the whole pond.

5, red skin disease, canker disease fish fin base hyperemia, redness and swelling, descaling, epidermis rot, muscle exposure. The disease mostly occurs in the high temperature season, prevention can be a large number of replacement of new water, regular release of raw lime 35-40ppm, dry pond exposure in winter. Treatment can be treated with bleach 1ppm sprinkled throughout the pond; oral furosulfonate mixture, 300g per 100kg surimi; intramuscular injection of penicillin, 3000 international units per kilogram of body weight.

6. The diseased carp parasites on the gills, skin and fins of the fish, which makes the Gill filament epithelium proliferate and deform, inflammatory edema, body surface damage, resulting in secondary bacterial infection and death. Treatment: 0.2-0 3ppm of trichlorfon was sprinkled throughout the pond.