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Reasonable stocking fish species
The reasonable stocking of fingerlings for stocking should be based on the requirement of wheel catching and maximizing the productivity of the water body. Under the premise of developing food fish to meet the market specifications, the specifications of stocked fingerlings should be appropriately reduced to facilitate the raising of aquaculture output. benefit. The white pheasant is the main species of the wheel catcher. Large size fish species of 150g-200g/tail are used as the basis for early arrests and their stocking rate is about 15%. When the water temperature is above 18°C, intensive feeding of 60-70 days can reach 550-600 g/tail, that is, it can be harvested and listed at the end of June and early July. Under normal culture conditions, the time to market specification is approximately 90 days. Put 20% of 100g/Wish medium-sized white peony, in the case of fertile water, can reach the market specification after about 80 days. The 50 g/tail fish species was the main body of the arrest and listing at the end of July and August, and the amount was 65%. The squid is mainly eaten by zooplankton, and its growth speed is very fast, but its ability to compete for food is weak. The stocking specification is 100 g/tail. Herring stocking 500g-700g/tailed second-instar fish can eat large snails and aquatic insects in the pond. It can not only control the proliferation of these benthic animals, consume fertilizer and oxygen, but also reduce their host-transmitted diseases. . Grass carp stocking specifications are: 20% for second-instar fish species of 400g-500g/tail; 40% for 300g/tail; 20% for 100g/tail; and 20% for tailstock weight of 30g-50g The grass carp, after one year of raising, can be used as a fish seed that can be used for the second year after it has reached the market specification and has not reached the market specification. The squid has a strong ability to compete for food and has a strong ability to excavate sediment organisms, making the pool water turbid and affecting the growth of other fish. Also damage the pond, stocking specifications should not be too large, generally 30 grams -50 grams / tail can be. The stocking size of C. edulis is 50-75 g/tail, which allows it to develop into a commercial fish for larger individuals. Catfish stocking specifications are around 30 grams/tail, which can save fish species expenditures and also achieve higher fish yields. The suitable density of fingerling stocks for stocking is too small, the yield is low, and the efficiency is poor. If the density is too large and exceeds the bearing capacity of the water, it will cause the dead individuals of dead fish or fish to reach the market specifications. The following describes several technically feasible and economically reasonable stocking modes: 100-120 kg of high-yielding and high-efficiency Muping fish species, 6-7 times the weight gain of fish species, a 30% increase in weight gain rate, and a 10% reduction in production costs - 15% also reduces the onset and pan-pooling and reduces the risk of breeding. Aquaculture production can still reach 600-700 kg/mu. The medium-yield type of this stocking mode is suitable for newly excavated fish culture ponds and underinvested areas. It is characterized by moderate aquaculture production and yields of 300-400 kilograms, but the benefits are very good. 50-60 kilograms of fish are put in the acre. The use of fish species is less, the fish growth is faster, the investment is smaller, the utilization rate of feedstuffs and fertilizers is high, and it is easy to target the advantages of market conditions and obtain higher benefits. This type of stocking type, which is mainly based on nesting, is more suitable for large and medium-sized areas with difficult sources of water and fish. Winter and spring plan to raise the production requirements of the fish species by 30% -40%, summer (in mid-June) nutrition remaining 60% -70% of the species. This not only solves the problem of insufficient fish species, large out-of-order fish species, and low survival rate, but also allows the funds of the purchased fish species to be used for feed and fertilizer input, and implements intensive feeding, so that the nutritious fire fish species can be large that year. Partially meets product specifications. There is no strict regulation on the ratio of stocking and stocking for rational stocking and stocking. From the perspective of most of the good economic efficiency breeding models, taking 400 kg per mu of adult fish as an example, the ratio of stocking and stocking is: 45 white plovers and 35.5 kg; 40 fish tails, 4 kg; grass carp 60-80 tails, 15-20 kg; carp 20 tails, 1 kg; 50 heads of carp head, 2.5 kg; carp 100 tails, 3 kg; herring 6-8 tails, 4 kg . Although the ratio of high-quality fish is not high, the fish stocks have low cost, low investment risk, large individuals that develop high-quality fish, and have a higher weight gain and better efficiency. This model can also be changed to high-quality fish, with the number of grass carp increased to more than 100, the number of head lice increased to more than 150, and the number of white plover to 350-400. This model is characterized by high input and high efficiency.