Summary of northern pond culture of golden crucian carp
The fish seed site of Kuandian County is located in the eastern mountainous area of Liaoning Province in northern China, with an existing pond area of 380 mu, concentrated and contiguous, easy to manage, and is the breeding base for cage culture seedlings in the county. In the past two decades, the scope of pond transformation is small, the pond is seriously aging, the bottom mud is too thick, the accumulation of toxic substances is too much, the breeding species is single, and it has always been based on carp, frame mirrors and grass carp, genetic diseases and infectious diseases have continued year after year, and every year there are individual ponds due to disease failure or high mortality rate of main breeding species, which brings major economic losses to farmers and restricts the healthy development of fisheries in the county.
In the absence of conditions for pond transformation, in addition to the regular prevention of fish diseases, breeding varieties should be changed, new varieties with strong disease resistance should be selected to cut off the transmission of genetic diseases and infectious diseases, and control the occurrence of fulminant fish diseases. Golden crucian carp is a new breed of excellent freshwater fish culture bred by the combination of conventional breeding and biotechnology breeding, with the national Tianjin Municipal Replacement Aquatic Breeding Farm with the scattered mirror carp as the mother and the red crucian carp as the father, and has the characteristics of high meat content, high nutritional value, wide temperature range, strong cold resistance and easy breeding. In 2016, the experimental breeding in The Fish Seed Farm in Kuandian County was started, and the breeding situation in the past two years is summarized as follows:
"Yunna" attacked Zhejiang
First, breeding advantages
1. Grow super fast. Since the golden crucian carp is a hybrid species, the gonads are not fully developed, its physiological infertility, no reproductive function, will not be mixed with other fish, will not destroy the breeding and ecological environment, all nutrients are used for growth. Therefore, it grows particularly fast, more than 2 times faster than ordinary crucian carp. After two years of breeding practice, the water splash (fry) stocked in that year can grow about 400g of adult fish by the end of the year, and the stocking of spring flakes can grow commercial fish with a tail weight of more than 800g. Because of its fast growth, short breeding cycle, low breeding cost, high yield and high efficiency, the economic benefits brought to farmers are considerable.
2. Strong adaptability
First, strong disease resistance. Judging from the areas that have been promoted so far, the golden crucian carp is not susceptible to disease and has not occurred large-scale diseases. Pond culture has a high survival rate due to its inability to become ill. The survival rate of water flowers (fry) to summer flowers out of the pond is more than 60%,; the survival rate of the pond from summer flowers to autumn flakes (fingerlings) is more than 80%,; and the survival rate of fish from fish fingerlings to commercial fish out of the pond is more than 90%.
Second, strong resistance to stress. Golden crucian carp is resistant to low oxygen, and when the dissolved oxygen of the aquaculture water is 3 to 4 mg/l, it can still eat and grow normally. It is resistant to low temperatures and can safely overwinter in a pool water environment with a water temperature of 1.5 °C and a water level of 1.2 m under ice. And good transport, no stress response, tight scales, no scales.
Third, the feed conversion rate is high. Golden crucian carp is an omnivorous fish, its feeding and digestion inherit the advantages of both parents, under pond conditions, the digestion and absorption performance of artificially prepared full-price feed is strong, the feed conversion rate is high, and the feed coefficient is low. The feed coefficient is 1.5 at the juvenile stage and only 1.3 from the fingerling to the adult stage.
The precious spiny catfish "swims" in Shangrao, Jiangxi
2. Breeding technology
1. Pond preparation. The adaptability of the golden crucian carp is extremely strong, and the requirements for the pond environment and water quality are not strict. In aquaculture, it is generally appropriate to choose 5 to 10 acres of ponds, pond water sources are sufficient, water retention performance is good, drainage is convenient, there is no pollution, the bottom of the pond is flat, and the silt is best not more than 10 to 15 cm. Each pond is equipped with a bait thrower and an aerator.
15 days before the stocking of fish species, drain the pond water, use quicklime or bleaching powder, carry out thorough pond cleaning treatment, turn the silt at the bottom of the pond with a wooden rake, expose to weathering and decomposition, fill the pond 3-5 days after filling, and filter the water inlet with an 80 mesh sieve silk net when filling the water to prevent the entry of predators such as wild trash fish, and the pond water level is between 0.6 and 2.5 m.
2. Seed stocking. Under normal circumstances, when the water temperature of the pond reaches 17 ~ 20 ° C, from the water splash to the summer flower, 200,000 to 400,000 water flowers can be stocked per mu of effective water surface; the stocking density of the commercial fish from the summer flower in that year is 4000 to 4500 summer flowers of 2-3 cm per mu, and the amount of stocking per mu should be adjusted according to the needs of the market for individual size. The stocking density from fingerling rearing to commercial fish is 2000 to 3000 fingerlings per mu that can be stocked with a size of 60 to 200g, and silver carp fry are also raised. Detailed stocking levels are shown in Table 1:
Table 1 Stocking status table
Seedlings should be selected with robust physique, neat specifications, intact scales, no disease and no injury, seedlings should be soaked in salt water for 5 to 10 minutes before stocking, and the temperature difference during stocking should not exceed 4 ° C.
3. Aquaculture management. After the seed is released, daily management is key.
(1) Water quality control. Water quality is one of the important conditions for raising good fish. The water quality of ponds where the golden crucian carp is raised is the same as that of other conventionally eating fish. In order to open food early and regulate the water temperature, the water level should be controlled at 1.0 ~ 1.2m, when the water temperature of the breeding pond reaches more than 20 ° C, the pond water level can be gradually increased, and when the pond water temperature reaches more than 25 ° C in midsummer, the water level of the breeding pond should be increased to the highest point of 2.5m. In the autumn, the water temperature of the breeding pond begins to decline day by day, and in order to make the water temperature of the breeding pond slowly decrease, the water level of the pond should be adjusted accordingly. During the high temperature season, new water should be filled with new water once or replaced with 30% to 40% of the old water at intervals of about 15 days, so that the pond aquaculture water quality should remain fat, live, tender and cool. The control of algae in the water is dominated by single cell algae such as diatoms and green algae, which are preferred by fish, and the water body is oily green and light brown.
(2) Feed feeding. The golden crucian carp feeds longer than other carp crucian carp and feeds almost all year round. When the water temperature of the culture pond rises to 6 °C, feeding should begin on sunny days. In order to enable the golden crucian carp to concentrate on feeding, it should be beaten on the hard object for 3-5 minutes before feeding to make a sound, and the principle of "slow-fast-slow" and "less-more-less" should be mastered when feeding. When the feeding began, the fish have not all arrived, the feeding speed should be slow, the amount of bait is small; after feeding for 2 to 3 minutes, the fish feeding is very strong, the feeding speed should be fast, the area of the thrown material should be enlarged, the fan shape is the best, and the feed amount is also large; after the fish have been fed for a period of time, a small number of fish have been fed and gone, and at this time it is necessary to gradually slow down the feeding and reduce the amount of feeding. The amount of bait should be controlled at 80% of the fish is full.
(3) Disease prevention and control. The golden crucian carp is extremely resistant to disease, and in recent years, it has rarely been infected with diseases in the promotion of breeding in various places, and it has been favored by farmers because it is not easy to get sick. But this does not mean that in any environment, under any circumstances at any stage of growth, there will be absolutely no disease. That is to say, the idea of "prevention as the mainstay, prevention is more important than treatment" can not be relaxed, in the feeding process, in strict accordance with the technical requirements of pollution-free aquatic products, the selection of low toxicity, high efficiency, no residue of green environmental protection fishing drugs for disease prevention and control, in addition to the fish species before the pond is thoroughly cleaned and disinfected, in the breeding every 20 days or so sprinkled with bleaching powder disinfection, the food field and tools should also be disinfected at any time, such as the discovery of abnormal fish, to diagnose early, symptomatic medication, in order to maintain the healthy growth of pond fish.
(4) Pond management. It is necessary to insist on 2 times a day to patrol the pond, once in the morning and once in the evening to observe whether the activity of the pond fish is abnormal, whether there is a lack of oxygen in the pond water, whether there is a precursor to floating head, whether there is a change in water quality, the level of the pool water level, but also to check the feeding situation of the fish, according to the feeding situation in time to increase or decrease the amount of bait, to avoid the waste of feed and pollution of water quality. In the process of breeding, it is also necessary to maintain the environmental hygiene inside and outside the pond, and outside the pond, it is necessary to remove weeds and debris on the shore in time, and in the pond, timely fill new water or change water, and clean up the debris in the pond in time. It is necessary to regularly determine the water quality indicators such as dissolved oxygen, ph value, and ammonia nitrogen of the breeding pond, so that the dissolved oxygen is maintained above 4.5mg/l, and the ph-value is maintained at 7 to 9. In addition, it is necessary to strengthen the night management of cloudy, rainy and high temperature seasons, and solve and deal with abnormalities in a timely manner. Keep records of pond culture.
Third, the efficiency of breeding
In 2017, the Three Groups of Golden Crucian Carp Ponds were stocked in Three Groups of Kuandian County Fish Seed Farm, and on May 3, 70,000 Golden Crucian Spring Flakes fingerlings were stocked in Tianjin For New Aquatic Seed Farm, and about 2,300 fingerlings of about 50-100g per mu of water surface were stocked. From November 5th to 8th, the pond received 28,000 kg of commercial fish weighing more than 400g and sold them for 16 yuan per kilogram, with a total income of 448,000 yuan. The situation of the pond is detailed in Table 2:
Table 2 Table of harvests
Expenses: Fish species cost 53,000 yuan, bait cost 182,000 yuan, water and electricity costs 10,000 yuan, labor costs 20,000 yuan, other 10,000 yuan, a total of 275,000 yuan, a total of 194,300 yuan net profit.
The input-output ratio is: 1:1.71. At present, the golden crucian carp has become one of the main breeding species in the ponds of the county, and has successfully replaced some old varieties with poor cold resistance and weak disease resistance, achieving the goal of promoting a variety and promoting the development of an industry.