Knowledge of pond fish culture

Pond fish culture refers to fish culture in artificial or natural still water ponds, also known as fish culture in inner ponds. The water body of the pond is small, easy to be controlled manually and easy to manage. Comprehensive technical measures can be adopted for intensive culture to increase the yield per unit water area. The production process is divided into four stages, the fry is obtained by artificial propagation, and the fry is cultivated into a commercial fish in the same year or the next year, and some fish continue to be cultivated into parent fish, and they can also be specialized in one of these stages according to their needs. China's pond fish culture area, per unit yield and total yield all rank first in the world. The main countries in the world that raise fish in ponds are India, Southeast Asian countries, Japan, Russia, the United States and so on. The main techniques of pond fish culture include mixed culture and close culture, rotation, daily management and comprehensive management.

Mixed culture and close culture

Mixed culture and reasonable close culture in the same pond have different habits, different feeding habits or the same species with different specifications, which is the core of Chinese pond fish culture technology. Silver carp and bighead carp live in the upper layer of the water, grass carp and blunt snout bream live in the middle and lower layers of the water, and herring, mud carp, common carp, crucian carp and non-crucian carp live in the bottom of the water. When these different kinds of fish are mixed in the same pond, it can not only increase the stocking amount per unit area of the pond, but also make full use of all kinds of bait resources in the pond and produce mutually beneficial relationship because of the different bait needed by all kinds of fish. it also prevents the eutrophication of the water body and improves the production conditions of the pond. The mixed culture of fish of the same species and different specifications can produce large-size fish species while producing edible fish, thus reducing the ponds for cultivating fish species and expanding the breeding area of edible fish. In a reasonable range of density, as long as the water temperature is suitable, the water quality is good, the proportion of mixed fish and the specification of stocking fish species are appropriate, the bait quality is adequate, and the feeding management is meticulous, the yield will be increased.

Capture and release by rotation

That is, to release enough fish at a time, after raising for a period of time, catch some of the adult fish that meet the commercial specifications in batches, and then replenish the fish species appropriately. By using this method, the unit water body of the pond can always maintain a suitable density, so as to increase the fish yield per unit area.

Daily management

Controlling the color of pool water is the main technical measure of daily management. The good water color such as bean green and tea brown is a comprehensive index, which indicates that cryptoplankton, diatoms and other algae are the high quality populations of phytoplankton in the pond water. For example, these algae form blooms, indicating that all kinds of nutrients are abundant and the metabolic intermediates decompose quickly. Dissolved oxygen is in good condition. In order to make the water color good, timely and appropriate amount of fertilization and injection of new water are needed to discharge the pool water. The bait is mainly aquatic grass, dry grass and algae, supplemented with bait, cruller, cereals and bran or field snails, shellfish and so on. Bait should be timely, appropriate and fixed point, in order to check the feeding condition of fish. The purpose of fertilization is to cultivate plankton in the pond, mainly poultry, animal manure and green manure. Because of the high stocking density and large amount of bait fertilizer in the high-yield intensive culture pond, it is easy to lead to the decrease of dissolved oxygen and threaten the survival of fish, so it is necessary to inject new water or oxygen in time to avoid the phenomenon of fish flooding and floating head.

Integrated management

In order to make full use of agricultural natural resources, agricultural and sideline products and their processing wastes, save energy, maintain ecological balance and improve economic benefits, China often focuses on pond fish farming and integrated management with livestock, poultry, sericulture and vegetable cultivation. For example, mulberry base, sugarcane base, fruit base and fish ponds in Guangdong are to cultivate fish such as mulberry, mulberry leaves, silkworm sand and silkworm pupae on the banks of fish ponds, fish manure ponds and pond mud to fertilize mulberry, so that fish, mulberry and silkworms can all grow well. to form a virtuous circle artificial compound ecosystem in which water and land promote each other.