Culture technology of bighead carp

Fish fry culture

Two-stage cultivation method is generally adopted in Shanghai, that is, fry cultivation 15 ~ 20 days to grow into 16.5 ~ 26.4 mm or 30 ~ 6.5 mm summer flowers, and then summer flowers are cultivated into fish species (the cultivation method is the same as herring). In the seedling stage, the secondary culture also needs a single culture, because silver carp moves fast and has strong competition for food, while bighead carp moves slowly and has weak competition for food. For example, if silver carp and bighead carp are mixed, they may not grow well because they cannot get enough food. If mixed, it can only be mixed. Mixed culture of silver carp is not allowed in ponds dominated by bighead carp, even if a small amount of silver carp is raised in ponds, it may have an adverse effect on the growth of bighead carp. In recent years, first-class aquaculture methods have been tried in Jiangsu, such as Suzhou Aquaculture Farm, with 1 ~ 12000 fish per mu and about 1000 fish per mu. The specifications of fish coming out of the pond in winter are all165 ~ 98 mm.

Adult fish culture

Selection and cleaning of the pond: the pond area is 5- 10 mu, the water depth is 1.5-2.5m, the water quality is good, the water source is abundant, the environment is quiet, the sunshine is sufficient, and the wind and the sun are avoided. There is less silt at the bottom of the pond, and the silt in the pond does not exceed 30cm, so it can only slightly penetrate into the pond. The water source requires good water quality, no pollution, and good conditions for pond injection and drainage. Water injection should be strictly filtered to facilitate water injection and drainage. Before the pond is used, it should be cleaned and disinfected. 5-7 days before releasing the fingerlings, 200-300 kilograms of organic fertilizers such as fermented pig manure and duck manure were applied to the water surface per mu 1 m to fertilize the pond, so as to cultivate palatable biological bait for the rapid growth of fingerlings. The water inlet must be equipped with facilities to intercept wild miscellaneous fish, and the bottom of the pond should be flat. 75 to 100 kg of quicklime should be used for each mu of pond, and the pond should be cleaned by dry method when the water depth of the pond is 10 cm, so as to kill pathogens, wild miscellaneous fish and enemy creatures in the pond and provide a good living environment for the growth of fry.

Requirements for release of fry: Fish release requires good body shape, strong activity, strong physique, consistent specifications, no injury, lively swimming, and ensure that they can release enough at one time. Generally speaking, the stocking density time is 700 silver carp per mu, silver carp per mu 100, with a small amount of crucian carp. The stocking time is February-March, the water temperature is 8- 10℃, and the box must be strictly disinfected. Before stocking fry, apply base fertilizer. Organic fertilizers, such as manure and green manure, are mainly applied in winter and spring, and the transparency of water quality is kept at about 30cm. Fresh water should be added frequently in summer and autumn, generally 15 days 1 time, so as to keep the transparency of the pool water at about 20cm, and the water quality is rich, lively, tender and refreshing. The color of water is brown and yellow-green. In summer, you can also use inorganic fertilizer, ecological fertilizer sold in the market and special fertilizer for bighead carp.

Feeding management: Do a good job of "three patrols and four inspections" in the morning, middle and evening, master the climate, fish situation and illness, keep the fish growing rapidly, and inject water regularly to prevent floods and escapes. The bait for raising parent fish must be diversified, and both plant bait and animal bait should be taken into account to meet the needs of fish for various essential amino acids, but the temperature difference between water before and after changing water should not exceed 3℃. Do not inject water when feeding to avoid feeding fry. Bighead carp is a kind of mild filter-feeding fish, which does not compete for food or grab food. When other fish grab food, they just wait and see outside and don't enter the food table to grab food. Therefore, feed-fed bighead carp can only be raised separately, and other herbivorous fish, including silver carp, cannot be mixed. Feeding adheres to the "four determinations" of quality, timing, positioning and quantification, and feeds according to the feeding rhythm of fish species.