Earthen ponds and cement ponds are supported by intensive rearing methods of yellow jaw fish fry
Liang Hong et al
1. Materials and methods
1. Preparation of the incubation pool
(1) Bait cultivation pond preparation. The biological bait breeding pond directly uses two ponds of yellow jaw fish commercial fish farming ponds, with a total area of about 8000 meters2, and the water source is used by river water. In early April, when the temperature is stable at about 18 ° C, the disinfection begins, the first water is injected without bottom (10 to 30 cm), the water injection is filtered with a 40 mesh nylon sieve silk mesh, and the whole pond is sprinkled with quicklime 50 kg/mu mixed with pulp, and the fermented pig manure is stacked in the fish pond 200~300 kg/mu for backup.
(2) Cement pool preparation. Yellow jaw fish splash breeding pond area of 20 meters 2, water depth of 100 cm, is a brick cement structure, supporting water injection drainage pipes, aeration pumps, shade nets and other facilities, the water source using hoarding pond filter water. In late April, the cement tank was cleaned and disinfected with trichloroisocyanuric acid, and the seedlings were washed with clean water three days before the seedlings were filtered and injected with water 60 cm deep for later use.
2. Breeding and fishing methods of bait organisms In the Yangtze River Basin area
The rearing season for yellow jaw fry is from April to June. 20 days before the introduction of yellow jaw fry (mid-April), water is injected into the bait biological breeding pond, the water level is maintained at about 60 cm, and the fermented pig manure is dispersed, and urea is supplemented with 2 kg/mu and calcium superphosphate 0.5 kg/mu. The transparency is maintained at about 25 cm. When the branches begin to appear in the water body, start adding water in stages of 10 cm every 5 days until the water level is 100 to 120 cm. Timely topdressing: urea 2 kg / mu, calcium superphosphate 0.5 kg / mu (can be once every 5 days), while sprinkling EM bacteria culture solution 2.5 liters / mu, so that the transparency is maintained 20 ~ 30 cm; after 20 days, the branch horns reach the peak, especially in the morning pond edge branch horn group aggregation density of 2600 / liter; the peak of the branch horn should be fished in time as bait, and the daily harvest rate is about 30%. Yellow jawfish splash prey on rotifers and branch horns, start fishing bait organisms can be fished along the edge of the pool with 100 mesh nylon net, water splash breeding after 3 days using 60 mesh nylon net fishing, branch horns in the morning along the edge of the pond can reduce the workload. When the water transparency of the branch horns is close to 30 cm at the peak period, in addition to applying topdressing and EM bacteria liquid, it is timely sprinkled with soybeans 1.5 kg/mu and sprinkled once a day.
3. Intensive rearing method of yellow jaw fish fry in order to meet the present
The fish species of the commercial yellow jaw fish need to be raised in 5 fish ponds, and 500,000 yellow jaw fish are purchased to enter the water splash, all placed in 5 20 m2 cement ponds, the density is 5000 fish / m2, and the water depth is maintained at 60 cm; before the seedlings are released, the bait organisms (rotifers, branches) are caught with a 100 mesh screen silk net 2 kg; each cement pond is placed 6 inflatable heads to prevent hypoxia, and then every morning from the bait biological breeding pond, the rotifers and branches are fished out of the bait biological breeding pond, and each pond is thrown 2 to 3 kg, and the range of activity of the yellow jaw fry is small. The biological density of the bait is maintained at 2500/L for the fry to feed, and after 3 days the bait organisms are caught using a nylon net of 60 mesh. According to the biological density of the bait in the breeding pond, the bait can be supplemented once in the afternoon, and as the fry grows, the water level gradually deepens to 100 cm, and after 10 days of cultivating yellow jaw fry reaches about 2 cm, divided into 10 cement ponds for cultivation, and the density remains at about 2500 fish/m2. Before the release of seedlings, 2 kg of branch horns are stocked in each breeding pond, and the amount of bait is adjusted every day according to the density of branch horns in the water, and as the feed intake of fry increases, the bait is supplemented once a day in the afternoon. After 18 days of rearing fry reach 3 cm, they are transferred to earthen ponds for commercial fish rearing. A total of 460,000 yellow jaw fish species were produced from the cement pond, and the survival rate of water splash was 92%.
2. Results and analysis
The earthen pond cultivates bait organisms, and the cement pond cultivates yellow jawfish with a splash of 3 cm in 18 days, which is about 5 days earlier than the cultivation time of the earthen pond. 500,000 splash fry obtained 460,000 fingerlings, and the survival rate of fry rearing was 92%, higher than that of earthen ponds; 18,600 m
2 Yellowtail goods
Fish breeding ponds require 200 m of fingerlings
2 cement ponds can be cultivated
Out, the cement pond breeds yellow jaw fish species with neat specifications and strong physique, and the survival rate of commercial fish breeding is high. The ratio of the area of the yellow jawfish cement breeding pond to the bait source pond is calculated to be 1:15. In the process of breeding yellow jaw fry, in order to prevent water pollution and remove feces in time, continuous oxygenation, do a good job of water quality monitoring, timely water change, to ensure that the water quality is clean and the dissolved oxygen is rich.
3. Discussion
1. The superiority of cultivating branches and horns in special ponds Fertilizers use light energy to complete the synthesis and transformation of matter to form bait for branch horns, with short food chain, large biomass and high yield of branch horns; special pond cultivation of branch horns avoids breaking the balance of plankton ecosystems due to fish fry stocking, and improves the yield of branch horns. Through the harvesting, topdressing, water quality regulation and other methods of branch horns, the balance of plankton ecosystems is maintained, the material circulation and transformation are promoted, and the high yield period of branch horns is maintained for more than 20 days, so that livestock and poultry manure can be used and bait costs are saved.
2. Advantages of intensive breeding of fry Yellow jaw fish splash stage individual small, less absolute oxygen consumption, strong sociality, small space demand, suitable for high-density stocking; large bait density, fry feeding uniform, seedling specifications neat, sufficient feeding residue less feeding, high survival rate. Cement pond cultivation of yellow jaw fry, bait, sub-pond operation is convenient, accurate counting, labor saving; with branches and horns as the bait for yellow jaw fish fry, rich in nutrients, fast consumption and absorption speed, high conversion rate, non-polluting water quality, fast growth of fish fry, high survival rate, yellow jaw fish fry cement pond cultivation than traditional earth pond cultivation survival rate increased by about 50%, breeding time shortened by more than 5 days, the advantages are obvious.
IV. Conclusion
The test proves that the survival rate of fish fry is about 50% higher than that of the traditional production mode, and the fish fingerling breeding time is more than 5 days in advance; the fish fingerlings required for 100 acres of yellow jaw fish adult fish breeding pond can be cultivated from 1 mu cement pond (ratio 100:1), and the ratio of bait breeding pond and cement pond is 15:1.
