one. In addition to conventional requirements for stocking types and natural foods, in principle, the natural food biomass in the pond should be fully utilized by the breeding organisms.
1. The percentage of production of phytoplankton, bacteria, and zooplankton in ponds that were not fertilized with fertilization and artificial feeding and fertilization was 98.7, 94.9, and 97.9, respectively.
2. Professor He Zhihui from Dalian Fisheries University determined that 99.8% of the total amount of bait was found in phytoplankton, bacteria, and zooplankton in fish ponds in the aquaculture base of the school. Natural food bioproductivity 4.5g/M2. (1989)
two. The appropriate specification of stocking size and gain multiples for stocking of fish should be based on the climate characteristics of each region and the length of the fish growth period, the fish growth pattern, the specifications of the planned fish out of the stock, the stocking density and the planned yield; Rotation, whether or not to raise large fish species and other factors. Comprehensively consider the weight gain of farmed fish.
1. The weight gain multiples of the year: 100~11398 carp, 753~2126 carp, 213~1950 carp, 25~227 tilapia, 1048~1551 pupae.
2. Weight gain multiples of Erling fish: 25~96 species of carp weighing 15~40 grams; 9~34 species of fish weighing 50~100 grams; 10 species of carp and carp weighing 10~20 grams ~38.5; fingerlings weighing between 75 and 100 grams were 7 to 12.6; fingerlings weighing between 200 and 250 grams were captured between 2.3 and 6.8 in August of that year.
three. Stocking species and pond fish stocks Pond natural food organisms provide fish production such as earthworms and other filter-feeding (water fish) fish, with a high limit of about 400 kg. The significant increase in fish production should be based on increasing the stocking ratio of fish (eat fish), improving feed quality, and strengthening oxygenation measures.
1. Carp: carp storage 300kg/mu or more, the most suitable ratio is 4~5:1;
The stock of carp is more than 200kg/mu, and the optimum proportion of carp is 3:1;
The stock of carp is 100~150kg/mu, and the optimum ratio of carp is 2:1.
2. Mandarin fish, tilapia, and white gizzards: Their polyculture ratio depends on their ability to filter and feed, and their ability to filter foods is stronger than that of tilapia and white gizzards. However, the eel's ability to swallow is less than that of the latter. Therefore, the stocking ratio of tilapia and silver carp should be lower than that of alfalfa, otherwise it will inhibit the growth of carp. The stocking ratio of quail and tilapia and white plover is 2 to 3:1.
3. Grass carp and squid: These two fishes have different diets and habitats. The natural food used in the pond is also different, but the ability of the grass carp to eat more is higher than that of the carp when feeding artificial bait. Therefore, the carp can be kept less in the main grass carp pond in order to make full use of benthic organisms and artificial baits. The main carp pond usually does not contain grass carp. In ponds with aquatic plants, depending on how many acres of aquatic weeds, about 20-50 grass carp weights of about 100 grams are weighed to control aquatic grasses. The main grass carp ponds, depending on the amount of grass adult fish, can stock 50 to 100 tail carp species.
4. Herring and squid: They both inhabit the bottom and have some overlap in their diet. In the pond where the main herring is reared, only a small amount of carp species can be placed, with no more than 50 per mu. The pond that raises the eel generally does not place herring.
5. Squid and mackerel: There is also overlap in the feeding habits of the two fish. They compete for large zooplankton in the same pond. Therefore, less carp is placed in the main carp pond to effectively use small zooplankton and control rotifers. Biomass to avoid causing hypoxia. However, the amount of carp stocks can only be controlled by one-third of the carp, otherwise it will inhibit the growth of carp. Soviet scholars (XAPYPTOHOBa; 1980) pointed out that 50% of artificial diets and 50% of natural diets are the fastest growing. This also shows that the main squid pond should not overstock squid.
four. Stocking species and density In general, stocking density is positively correlated with fish yield in a certain range; it is negatively correlated with the out-of-water specification. When the stocking density exceeds this range, both the fish production and the out-of-water specification decrease.
1. Squid: The stocking density of common carp summer flowers is generally 500 to 600 (mixed yield per mu up to 400 to 500 kg). The stocking density of anchovy springs is about 500 mu per mu (up to 700-800 kg per mu). When the pond conditions are good, the feed quality is high, and the oxygen enrichment equipment is perfect, the stocking capacity of mu can reach 1000 to 1500 tails (up to 1300 to 2000 kg of mixed-breeding yield).
2. Grass carp: The stocking density of grass carp depends on the planned yield, generally adopting large-, medium-, and small-scale polyculture (large grass grass species 500-700 g/tail, medium size 150-250 g/tail, small size 20-50 g/mu. ). For example, a total of 900-1,000 kilograms of mixed crops will be stocked, and 80 to 100 tailstocks of large-scale species of grasses will be stocked; 120 in the medium specification and 200 in the smaller size.
3. The stocking density of eel is about 240 to 350. The proportion of squid depends on the size of the squid. Generally, squid has a larger size and can be put in more suitable. The percentage is controlled from 10% to 15%. However, it should not exceed 20%.
The main carp ponds are mainly fertilized, and carp only feed on natural foods, and their mu yield can reach 113-417 kilograms. More than 300 kilograms or more, most use round catch.
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