Sunlight greenhouse overwintering cultivation method for juvenile coilia ectenes in northern area

Abstract

The invention relates to the field of coilia ectenes fry cultivation, in particular to a sunlight greenhouse overwintering cultivation method for coilia ectenes juvenile fishes in northern areas. The method comprises the key links of coilia ectenes juvenile fish culture before overwintering, sunlight greenhouse soil pond transformation, sinking aquatic plant planting, preparation before fish putting, small shrimp putting, coilia ectenes juvenile fish putting, daily operation management, harvesting and the like. In order to solve the problem of stress of juvenile coilia ectenes and improve the overwintering success rate, a sunlight greenhouse is transformed to improve the pond water temperature in the overwintering period, and a water purification and water pushing system is additionally arranged to improve the circulating culture capacity of a soil pond. An automatic circulating water management mode is adopted, so that the labor cost is reduced, and the influence of human errors on overwintering production is reduced. The overwintering cultivation method is an effective way for solving the overwintering problem of the coilia ectenes under the artificial condition in the northern area, the overwintering cost of the coilia ectenes in the soil pond is greatly reduced, the overwintering risk is reduced, and the overwintering success rate is increased.

Description

Technical Field

[0001] The present invention relates to the field of Coilia nasus fry cultivation, and specifically to a method for overwintering Coilia nasus juvenile fish in a solar greenhouse in northern regions. Background Art

[0002] Coilia nasus (scientific name: Coilia nasus) is a fish of the family Engraulidae and the genus Coilia. Its body is silver-white. The dorsal side has a darker color, being cyan, golden yellow or greenish-yellow. The abdomen is lighter in color. The caudal fin is gray. Because people in Shanghai have the custom of "eating Coilia nasus before the Tomb-Sweeping Festival", and coupled with the extremely small catch amount, Coilia nasus was once known as an extremely expensive fish, a fish worth ten thousand yuan. Due to overfishing by humans, Coilia nasus has also faced population extinction. The population of Coilia nasus in the Yangtze Estuary has been decreasing year by year and was included in the "Red List of Endangered Species of the International Union for Conservation of Nature" in 2017.

[0003] The patent with the publication number CN109548719A proposes a method for mixed overwintering culture of Portunus trituberculatus, Takifugu rubripes and Ruditapes philippinarum. A protective net is used in the Ruditapes philippinarum culture area. On the one hand, the protective net prevents the sand in the culture pond from flowing out with water replacement, and on the other hand, it plays a protective role for Ruditapes philippinarum. It mainly aims at preventing predation in polyculture and does not carry out overwintering cultivation in combination with the habitat habits.

[0004] The patent with the publication number CN212993857U proposes an intelligent temperature reduction system for aquaculture ponds. It realizes temperature reduction in summer through sunshade nets and underwater adjustable oxygen pumps, observes the underwater situation through cameras, timely adjusts the lowering and rising heights of the oxygen pumps, and sets the oxygen pumps to be turned on to realize the underwater ventilation function. However, it does not involve temperature regulation during the overwintering period and lacks solutions to the problems of "low temperature, low dissolved oxygen and water quality deterioration" during the overwintering period in northern regions.

[0005] The patent with the publication number CN221104512U proposes a fishery aquaculture device that can regularly increase oxygen. By using a Roots blower, the oxygen-rich air is sent from the air pipe through an aerator into the oxygen delivery pipe. The oxygen delivery pipe sends the air into the microporous pipe. The microporous pipe is connected to the pipe entering the bottom of the pond. The micropores on the wall of the microporous pipe uniformly release gas in all directions in the water body, directly sending the oxygen-containing air to the bottom of the pond, and at the same time bringing out the harmful gases at the bottom layer. The rotational movement of the water flow diffuses the oxygen-rich water around the microporous pipe outward, realizing uniform oxygenation of the whole pond water. It does not consider the requirements of Coilia nasus for the "microhabitat" during the overwintering period (such as a shelter for avoiding low temperature and a spawning substrate), and the functional zoning is single, not meeting the special habitat requirements of Coilia nasus.

[0006] In the natural environment, Coilia nasus feeds on plankton and live fish and shrimps, which causes great difficulties in artificial breeding and fry cultivation. Coilia nasus has a relatively strong stress response and will die soon after being caught from natural waters. Therefore, the stress problem during the cultivation of Coilia nasus is also one of the difficulties in technical research. Under the breeding conditions in the north, Coilia nasus needs to experience a long wintering period, which poses high requirements for the nutritional reserves, wound repair, water quality regulation and bait supply of fry. Due to the above reasons, the breeding and fry cultivation of Coilia nasus have always been difficult to break through. Summary of the Invention

[0007] In view of the above problems, the purpose of the present invention is to provide a method for cultivating juvenile Coilia nasus in a solar greenhouse for wintering in the northern region, which can effectively repair the stress response caused by environmental changes and improve the wintering success rate of Coilia nasus in the northern region.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A method for cultivating juvenile Coilia nasus in a solar greenhouse for wintering in the northern region, the specific process is as follows:

[0010] (1) Cultivation of juvenile Coilia nasus before wintering

[0011] Before the wintering work, the Coilia nasus fry go through the stages of fertilized egg hatching and fry cultivation, with a body length of more than 7 cm, disease-free and injury-free, and feeding on live bait organisms; when the outdoor water temperature is 15 - 17 °C, they are transferred to the solar greenhouse of the cultivation system for wintering cultivation work;

[0012] (2) Transformation of the soil pond in the solar greenhouse

[0013] Select a soil pond with an area of 2 - 4 mu and an aspect ratio of 8 - 10:1, drain the pond water, and dry it for 20 - 40 days; remove the silt at the bottom of the pond, and tamp the bottom ground with tools; backfill part of the original pond bottom mud to restore some functions of the pond bottom and loosen the soil to prepare for planting aquatic plants; divide the functional areas of the breeding area and the purification area, lay microporous aeration discs at the bottom of the breeding area, and arrange filter ponds and water pushing equipment in the purification area. The breeding water from the breeding area is sent back to the breeding area by the water pushing equipment after passing through the filter ponds in the purification area;

[0014] (3) Planting of submerged aquatic plants

[0015] Inject water into the soil pond to a water depth of 0.5 - 0.7 m, and filter the water inlet with a 60 - 80 - mesh sleeve net to prevent wild fish from entering the pond; plant aquatic plants in the soil pond, and the area of aquatic plants accounts for 1 / 3 - 2 / 3 of the total area of the breeding area, with 100% coverage in the purification area;

[0016] (4) Preparation before releasing fish

[0017] Add water to a water depth of 1.0 m, start the water-pushing equipment in the purification area to increase water body fluidity; release small-sized cultured fish in the aquaculture area and feed them three times a day to rapidly enhance the probiotic purification ability of the purification area; adjust the room temperature by ventilation, control the water temperature above 16°C and not exceeding 22°C; patrol the pond twice a day, morning and evening, to monitor water quality indicators. When the water quality indicators are within the safety limit, release small-sized shrimps.

[0018] (5) Release small-sized shrimps

[0019] Set up a dragnet in the aquaculture area and combine it with setting up ground cages to capture small-sized cultured fish, and purchase wild or cultured small-sized shrimps; release the shrimp fry with a body length of 0.8 - 1.2 cm at a stocking density of 8 - 12 kg / mu. After the small-sized shrimps enter the water, they will disperse immediately and hide in the waterweeds.

[0020] (6) Release Coilia nasus larvae

[0021] Coilia nasus larvae that have been cultivated for at least 4 months, with a body length of more than 4 cm, disease-free and injury-free, and strong constitution, are arranged for preparation before winter transportation; according to the preparation of the winter sunlight greenhouse, start the winter transportation process after the winter equipment operates normally; prepare fishing nets, select summer flower nets, and after stopping feeding for 24 hours, place the summer flower net close to the ground, pull the summer flower net to drive the Coilia nasus larvae, and the advancing speed does not exceed 0.05 m / s, and pause for 2 minutes every 10 minutes of pulling the net.

[0022] (7) Daily operation management, including fry management, shrimp management, grass management, purification area management, equipment maintenance, and rain and snow maintenance.

[0023] (8) Harvesting, including Coilia nasus harvesting and small-sized shrimp harvesting.

[0024] In the northern region Coilia nasus larvae winter cultivation method in sunlight greenhouse, in step (1), the cultivation system is composed of a sunlight greenhouse and an earthen pond in the sunlight greenhouse. The support frame of the sunlight greenhouse is divided into a second structural support member on the sunny side and a first structural support member on the shady side. The first structural support member and the second structural support member are inclined to form a "people"-shaped support frame; a sieve net is vertically installed at three-fourths of the area of the earthen pond along the length direction, dividing the earthen pond into two areas, three-fourths is the aquaculture area, and one-fourth is the purification area; among them, microporous aeration discs are laid at the bottom of the aquaculture area, a submerged plant planting area is arranged between adjacent two rows of microporous aeration discs, and the microporous aeration discs are evenly distributed on both sides of the submerged plant planting area at the bottom of the earthen pond; a waterwheel aerator is installed as the water-pushing equipment in the purification area, and the waterwheel aerator is separated by a partition net and is located at a corner of the purification area.

[0025] The method for overwintering and culturing juvenile Coilia nasus in solar greenhouses in the northern region, in step (2), when the soil at the bottom of the earthen pond is loose and prone to leakage, the pond bottom should be dug deeper, and the thickness of the water isolation layer should be increased by backfilling with clay; the microporous aeration disk is a coiled nano-aeration pipe with a diameter of 50 - 100 cm. The microporous aeration disk is connected to an air volume regulating valve, and the air volume regulating valve is connected to a Roots blower on the edge of the earthen pond through an air duct to form an aeration device; the aquaculture water from the aquaculture area flows successively into the brush area, biological purification filter area, and aquatic plant purification area of the purification area filter pond, and then is sent back to the aquaculture area by a water pushing device.

[0026] The method for overwintering and culturing juvenile Coilia nasus in solar greenhouses in the northern region, in step (3), the aquatic plants are one or more of Hydrilla verticillata, Elodea nuttallii, and Vallisneria natans.

[0027] The method for overwintering and culturing juvenile Coilia nasus in solar greenhouses in the northern region, in step (4), the small aquaculture fish are one or more of crucian carp, Leuciscus waleckii, and silver carp and bighead carp over one year old; the water quality indicators include water temperature, dissolved oxygen, pH value, ammonia nitrogen, and nitrite nitrogen. When the water temperature is stable at 16 - 22 °C and the contents of ammonia nitrogen and nitrite are within the safety limit, small shrimps are put in.

[0028] The method for overwintering and culturing juvenile Coilia nasus in solar greenhouses in the northern region, in step (5), a fishing net is pulled in the aquaculture area and combined with setting ground cages to capture other fish except silver carp and bighead carp; the small shrimps are one or more of Palaemonetes sinensis, Palaemon modestus, and Caridina serrata; a small amount of surplus should be reserved for the daily feeding amount to meet the feeding needs of small shrimps.

[0029] The method for overwintering and culturing juvenile Coilia nasus in solar greenhouses in the northern region, in step (6), anti-stress drugs should be put into the overwintering earthen pond 1 hour in advance to avoid stress reactions of fish bodies; the water used in the transportation process is modulated from artificial seawater crystals or natural seawater to a salinity of 3 - 10‰. The fry should be transported in a basin when they leave the water, and they should be sent into the transport vehicle with water all the way. Counting is required before entering the overwintering earthen pond, and the cultivation density during the overwintering period should not exceed 40,000 tails per mu.

[0030] The method for overwintering and culturing juvenile Coilia nasus in solar greenhouses in the northern region, in step (7):

[0031] ① Fry management

[0032] After the juvenile Coilia nasus enter the pond, the adaptation period for the fry is half a month. Closely monitor the survival status of the juvenile Coilia nasus and sprinkle anti-stress drugs according to the actual situation to avoid damage to the fish body caused by stress reaction; the floating feeding area is made of PVC plastic pipes with a diameter of φ50mm, a square floating feeding area with a side length of 1m, and good sealing treatment is done to keep the floating feeding area floating on the water surface; set 3 to 4 floating feeding areas around the earthen pond, put frozen cladoceran food, copepod food or frozen mantis shrimp into the floating feeding area and let it float on the water surface to gradually domesticate the juvenile Coilia nasus to feed; after half a month, start to increase the feeding amount of the juvenile Coilia nasus, based on the gradual dispersal of the feeding of the juvenile fish, and keep good feeding records to calculate the daily food intake;

[0033] ② Management of shrimp

[0034] After the small shrimp are put into the pond, they inhabit the waterweeds, pick up the remains of bait organisms and fish feces as food, clean the waterweeds and the waste residues at the bottom of the pond, and promote the secondary utilization of bait organisms; the small shrimp carry eggs and hatch out larvae, and the juvenile Coilia nasus catch the larvae to supplement their own nutrition; when the bait of the small shrimp is insufficient, feed the formulated feed for penaeid shrimp, with the crude protein content in the nutrient components above 42% and the crude fat content 8 - 12% to provide nutrition for the small shrimp.

[0035] ③ Management of grass

[0036] Regularly check the growth of the waterweeds. When the waterweeds grow wildly, they need to be harvested and cleaned in time; fish out the rotten and aging parts of the floating waterweeds and keep the vigorously growing ones; for floating aquatic plants such as duckweed and water hyacinth, tow them to the shore with a floating rope to ensure that the covered water surface area does not exceed 50%; the area of the submerged waterweeds growing and covering the bottom of the pond does not exceed 60%. If they grow to the water surface, they should be cut off in time to avoid occupying the water space, and the harvested waterweeds are towed to the shore.

[0037] ④ Management of the purification area

[0038] The water-pushing equipment in the purification area needs to run 24 hours a day, and the aeration equipment always pushes the biological purification filter discs to suspend in the filter pond; the planting area of the filter pond waterweeds in the purification area reaches 100%, but it is necessary to prevent them from growing too high; when they reach the water surface height, they need to be cut off in time to keep the water permeability; measure the water quality indicators entering and leaving the purification area every morning and evening to ensure that the ammonium nitrogen and nitrite nitrogen indicators meet the growth requirements of the cultured organisms.

[0039] ⑤ Maintenance of equipment

[0040] Regularly check the running status of the standby blower and water-pushing equipment to ensure the stable operation of the equipment; ensure the dryness of the thermal insulation layer on the top of the solar greenhouse and the stable operation of the rolling machine, and timely adjust the air supply strength of the aeration facilities in the aquaculture area to avoid stress reaction of the cultured organisms caused by human operation.

[0041] ⑥ Maintenance in rain and snow

[0042] During winter, ensure the structure of the solar greenhouse is intact, clear the snow on the surface of the greenhouse in a timely manner, and operate the rolling curtain machine for heat preservation according to the weather conditions.

[0043] In the method for overwintering and culturing juvenile Coilia nasus in a solar greenhouse in the northern region, in step (8):

[0044] ① Harvest of Coilia nasus

[0045] Turn off the water-pushing equipment in the purification area, take out the microporous aeration disks and floating feeding areas in the breeding area, arrange the floating aquatic plants on the water surface of the breeding area, and arrange workers to prepare for the netting operation; the netting steps are the same as the above-mentioned netting method in the earthen pond, and slowly capture the juvenile Coilia nasus with water at a uniform speed, and transport them with water to the outside.

[0046] ② Harvest of small shrimps

[0047] Adopt the method of capturing with a cage, place bait in the cage to attract small shrimps into the cage.

[0048] The design concept of the present invention is:

[0049] Since juvenile Coilia nasus has strong stress response, especially when changing the living environment (transferring from the outdoor earthen pond to the indoor earthen pond, during transportation), serious stress reactions will occur, resulting in juvenile Coilia nasus constantly hitting the wall and rubbing against the pond wall, causing serious abrasion and ulceration on the body surface and a large number of deaths in a short period. In order to solve the stress problem of juvenile Coilia nasus and improve the overwintering success rate, the present invention improves the water temperature of the pond during the overwintering period by transforming the solar greenhouse, and adds a water quality purification and water-pushing system to improve the circulating aquaculture capacity of the earthen pond. Create a symbiotic effect among various organisms to achieve a sustainable development model of harmonious coexistence of cultured organisms, gradually domesticate and feed frozen cladocerans, copepods, mantis shrimps, etc., improve the aquaculture efficiency, and further reduce the aquaculture cost. Adopt an automated circulating water management method to reduce the labor cost and the impact of human errors on overwintering production.

[0050] The method of the present invention includes multiple key links such as pre-overwintering cultivation, transformation of the earthen pond in the solar greenhouse, planting of aquatic plants, preparation before releasing fish, releasing small shrimps, releasing juvenile Coilia nasus, operation and maintenance, and harvesting. Build a three-dimensional ecological aquaculture model suitable for the overwintering and growth of Coilia nasus under artificial conditions, and utilize the symbiotic relationship among organisms to achieve the purposes of biological water regulation, biological sewage cleaning, biological disease control, etc., so as to support the pressure on the aquaculture environment caused by feeding frozen biological baits during the overwintering period of Coilia nasus, promote the growth and development of Coilia nasus from the aspect of nutritional supply, reduce many disease risks of Coilia nasus, and achieve the purpose of smoothly passing through the overwintering period.

[0051] Before the overwintering work, by transforming the earthen pond in the solar greenhouse, the original earthen pond is divided into two parts: a farming area and a purification area, creating a farming environment with flowing water and self-purification characteristics for Coilia nasus larvae. Effectively utilize the self-purification ability of the earthen pond, combine with the technical characteristics of the artificial purification area, and through electric power propulsion, achieve high-density, high-efficiency, and high-survival-rate overwintering production work.

[0052] Under artificially controllable conditions, submerged aquatic plants are planted in the restricted area of the farming area, and aquatic plants are arranged in the entire purification area. Floating aquatic plants are set on the water surface to provide shelter and spawning conditions for small shrimps; strengthen the absorption of water-soluble nutrients by aquatic plants, reduce the eutrophication degree of the aquaculture water body, and provide buffering capacity for the farming environment.

[0053] Construct an ecological cycle farming model integrating fish, grass, and shrimp. Feeding artificial frozen bait can greatly reduce the farming cost. Coilia nasus larvae feed on biological bait, enhancing the physical fitness of the cultured organisms and improving disease resistance; small shrimps pick up the feces and residual bait produced by Coilia nasus larvae, avoiding the damage to the water environment caused by large particles such as feces and residual bait. By improving the nutritional status of small shrimps, the egg-carrying ability of shrimps is improved, and the produced larvae can be used as bait for Coilia nasus; aquatic plants provide shelter and spawning places for small shrimps, and at the same time absorb the eutrophic substances in the water, greatly reducing the farming risk.

[0054] After the traditional earthen pond is transformed and combined with the solar greenhouse, the usage method of the traditional solar greenhouse is changed, greatly improving the snow removal and heat preservation effects. Before the wind and snow come, the traditional solar greenhouse usually covers the heat preservation layer to avoid the indoor temperature from dropping. In the present invention, before the wind and snow come, the heat preservation layer needs to be opened, and then put down again on the night after the snow stops. The snow on the top of the greenhouse will smoothly slide to the ground due to the plastic film and its own slope, which greatly facilitates the workers to clean. At the same time, due to the huge water body in the indoor earthen pond, the specific heat of water is much larger than that of air, and the water temperature usually drops by about 1°C, which does not affect the survival of the cultured organisms. Therefore, the accident of the solar greenhouse collapsing due to too thick snow accumulation is avoided.

[0055] Using the solar greenhouse for overwintering, when the outdoor temperature is -10°C, the indoor water temperature still reaches above 20°C, which fully meets the growth requirements of Coilia nasus larvae, small shrimps, and aquatic plants, is conducive to the reproduction of water body probiotics, and ensures the normal operation of the self-purification function of the entire system.

[0056] The present invention has the following advantages and beneficial effects:

[0057] 1. The present invention is suitable for fish species such as Coilia nasus that have the habit of migrating for wintering in the northern regions of China, and provides a complete wintering solution for them. In the northern regions of China, the wintering period is long. Taking the eastern part of Liaoning as an example, the ice-covered period of ponds usually exceeds 5 months; the temperature is low, and the lowest temperature can reach -20°C. Experiments have proved that artificially cultivated Coilia nasus cannot survive using the traditional method of wintering under the ice in earthen ponds. The present invention provides a new solution for the wintering of juvenile Coilia nasus under artificial conditions in the northern regions.

[0058] 2. The present invention combines a solar greenhouse and an earthen pond. By greatly adjusting the operation method of the traditional solar greenhouse, the risk of structural damage to the solar greenhouse caused by snow accumulation is significantly reduced, while not affecting the reproduction and growth of overwintering organisms such as Coilia nasus, and improving the survival rate of cultured organisms during wintering.

[0059] 3. The present invention combines a solar greenhouse with a traditional earthen pond, transforms the earthen pond into a cultivation area and a purification area, retains the self-purification ability of the traditional earthen pond, and uses the method of electric water pushing to significantly improve the purification ability of the entire cultivation system; cultivates probiotics, and uses the biological film technology to timely degrade soluble harmful substances such as ammonium nitrogen and nitrite nitrogen in the water, reducing the risk of poisoning to cultured organisms.

[0060] 4. The present invention constructs a trinity ecological cultivation model of fish, grass, and shrimp, and uses the coexistence and symbiosis relationship between organisms to improve the buffering of the cultivation system. Feeding artificial frozen bait significantly reduces the cultivation cost. Juvenile Coilia nasus feed on biological bait, enhancing the physique of cultured organisms and improving disease resistance; small shrimp pick up the feces and residual bait produced by juvenile Coilia nasus, avoiding the damage to the water environment caused by large particles such as feces and residual bait. By improving the nutritional status of small shrimp, the egg-carrying ability of shrimp is improved, and the produced larvae can be used as bait for Coilia nasus; aquatic plants provide a hiding place and a spawning place for small shrimp, and at the same time absorb the eutrophic substances in the water, significantly reducing the cultivation risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a side view of the appearance of the cultivation system dedicated for Coilia nasus during the wintering period of the present invention. In the figure, 1. Roller blind machine, 2. First structural support member (shady side), 3. Roots blower, 4. Ladder, 5. Exhaust fan, 6. Second structural support member (sunny side), 7. Door, 17. Solar greenhouse.

[0062] Figure 2 It is a top view of the internal earthen pond of the cultivation system dedicated for Coilia nasus during the wintering period of the present invention. In the figure, 8. Micro-pore aeration disk, 9. Floating bait feeding area, 10. Submerged plant planting area, 11. Waterwheel aerator, 12. Partition net, 13. Purification area, 18. Earthen pond, 19. Cultivation area, 20. Sieve net.

[0063] Figure 3This is a sectional view of the soil pond inside the cultivation system dedicated for Coilia nasus during the overwintering period. In the figure, 8 is the microporous aeration disk, 9 is the floating bait feeding area, 10 is the submerged plant planting area, 14 is the pond bank, 15 is the submerged plant, 16 is the ramming layer, and 18 is the soil pond. Detailed implementation manners

[0064] Next, the present invention will be further elaborated in detail through embodiments and drawings.

[0065] As Figures 1-3 shown, the present invention provides a cultivation system dedicated for Coilia nasus during the overwintering period in the northern region, which is composed of a solar greenhouse 17 and a soil pond 18 inside the solar greenhouse 17, and mainly includes: a rolling machine 1, a first structural support member 2 (shaded side), a Roots blower 3, a ladder 4, an exhaust fan 5, a second structural support member 6 (sunny side), a door 7, a microporous aeration disk 8, a floating bait feeding area 9, a submerged plant planting area 10, a waterwheel aerator 11, a partition net 12, a purification area 13, a pond bank 14, a submerged plant 15, a ramming layer 16, etc. The specific structure is as follows:

[0066] The support frame of the solar greenhouse 17 is divided into a second structural support member 6 on the sunny side and a first structural support member 2 on the shaded side. The first structural support member 2 and the second structural support member 6 are inclined and erected into a "person"-shaped support frame to ensure the strength of the solar greenhouse of the entire cultivation system. The shaded side has a larger slope, with an angle of 60 - 75° with the ground, and the sunny side has a gentler slope, with an angle of 40 - 45° with the ground. The support frame is built with galvanized steel pipes, and the front and rear sides of the support frame are respectively closed with wall structures. An exhaust fan 5 is installed on the upper part of the front closed structure of the support frame, and a door 7 is installed on the lower part. A ventilation opening is provided in the rear closed structure of the support frame. Both the ventilation opening and the exhaust fan should be equipped with louver devices to prevent cold air from flowing back.

[0067] A heat preservation layer such as a cotton quilt, a felt or a straw curtain is laid outside the first structural support member 2 to resist the invasion of the north wind in winter. A light-transmitting plastic film or a sunlight board is laid outside the second structural support member 6 to ensure sufficient light inside the solar greenhouse. A rolling machine 1 is installed at the overlapping part of the tops of the first structural support member 2 and the second structural support member 6, and the rolling machine 1 is used to roll up and down the heat preservation layer such as a cotton quilt, a felt or a straw curtain. A Roots blower 3 is arranged outside the solar greenhouse 17, and the Roots blower 3 enters the solar greenhouse 17 through a PVC pipeline and is connected to the microporous aeration disk 8 in the soil pond 18. A ladder 4 is installed outside the first structural support member 2, and the ladder 4 provides installation and maintenance for the rolling machine 1 at the top of the support frame.

[0068] The earthen pond 18 can be transformed from a traditional earthen pond. Its surface is treated with anti-seepage, and then covered with the original pond topsoil. The upper opening size of the earthen pond has a length-width ratio of 8 - 10:1, a depth of 1.5 m, and a slope ratio (the ratio of vertical height to horizontal width) of 1:1.5 - 2.0. The slope is attached with aquaculture geotextile to protect the soil. After the bottom of the earthen pond 18 undergoes natural settlement, it needs to be mechanically tamped to form a tamped soil layer 16 with a thickness of 10 - 20 cm, which is mainly used to enhance the structural stability and reduce water body leakage. The bottom of the earthen pond 18 can be paved with soft soil and a plastic net. The mesh size of the plastic net is 10 cm × 10 cm, preparing for subsequent planting of aquatic plants. The perimeter of the upper opening of the earthen pond 18 is a pond bank 14, and the pond bank 14 is 30 cm higher than the water surface of the earthen pond.

[0069] At three-fourths of the area along the length direction of the earthen pond 18, a 40-mesh screen 20 is vertically installed, dividing the earthen pond 18 into two areas. Three-fourths is the aquaculture area 19 (east side), and one-fourth is the purification area 13 (west side).

[0070] At the bottom of the aquaculture area 19, microporous aeration disks 8 are laid. Ensure that one microporous aeration disk 8 is laid per 10 square meters. The microporous aeration disks 8 are connected to a Roots blower 3 and supplied with oxygen by the Roots blower. The microporous aeration disk 8 is a cylindrical shape with a diameter of 80 cm and a height of 16 cm. The micropores on the microporous aeration disk have a size of 20 - 30 microns. A submerged plant planting area 10 is set between two adjacent rows of microporous aeration disks 8. The microporous aeration disks 8 are evenly distributed on both sides of the bottom of the earthen pond in the submerged plant planting area 10. The submerged plant planting area 10 is a long strip of earthwork with a height of 80 cm and a trapezoidal cross-section. Submerged plants 15 are planted in the submerged plant planting area 10. Submerged plants (such as Elodea nuttallii, Vallisneria natans, etc.) are planted in the aquaculture area, and the planting area accounts for 40% of the total area of the aquaculture area. Especially, aquatic plants need to be planted below the floating feeding area to provide a hiding place for small shrimps.

[0071] PVC pipes with a diameter of 50 mm are connected to form a square hollow floating feeding area 9 with a side length of 1 - 1.5 m. The floating feeding area 9 is set on the water surface of the aquaculture area 19, which can stably suspend on the water surface layer and automatically adjust its height with the change of water level, meeting the feeding habits of Coilia nasus (mid-upper layer feeding fish), and having functions of adapting to dynamic water level, precise feeding and ecological protection. It is a targeted design for the feeding habits of Coilia nasus during the overwintering period and the environmental characteristics in the north, solving the limitations of the traditional fixed feeding area and improving the aquaculture efficiency and water quality management effect.

[0072] In the purification area 13, a waterwheel aerator 11 with a power of 1 kW is installed. The waterwheel aerator 11 is separated by a partition net 12 and is located at a corner of the purification area 13 to promote the circulation of the water body in the entire earthen pond. The waterwheel aerator is responsible for surface aeration and water body circulation. The waterwheel aerator and the micro-pore aeration disk work together through different mechanisms to form a "three-dimensional aeration system". In addition, in the purification area 13, a combined planting method of floating and submerged aquatic plants can be adopted to purify the water quality.

[0073] Embodiment

[0074] Basic conditions: A square pond is about 3×667 m 2 , which is divided into a breeding area and a purification area after transformation. The solar greenhouse is equipped with a rolling machine and is equipped with aeration and water circulation facilities.

[0075] In this embodiment, a method for overwintering and culturing juvenile Coilia nasus in a solar greenhouse in the northern region specifically comprises the following steps:

[0076] I. Culturing juvenile Coilia nasus before overwintering

[0077] Before the overwintering work, the Coilia nasus fry have gone through stages such as fertilized egg hatching and fry culturing, with a body length of more than 7 cm, disease-free and injury-free, and can feed on live bait organisms. When the outdoor water temperature drops to about 15°C, they can be transferred to the solar greenhouse of the special cultivation system of the present invention for overwintering cultivation work.

[0078] II. Transformation of the earthen pond in the solar greenhouse

[0079] Select an earthen pond of about 3 mu with a length-width ratio of 8-10:1, drain the pond water, and dry it for about 30 days. Remove the silt at the bottom of the pond, and use tools to tamp the bottom ground of the pond to avoid leakage. If the soil at the bottom of the pond is loose and prone to leakage, the bottom of the pond should be dug deeper, and methods such as backfilling with clay should be used to increase the thickness of the water isolation layer. Backfill part of the original pond bottom mud to restore some functions of the original pond bottom and loosen the soil to prepare for planting aquatic plants. Transform functional areas such as the breeding area and the purification area. In the breeding area, a micro-pore aeration disk is laid at the bottom of the pond. The micro-pore aeration disk is a coiled aeration pipe with a diameter of 80 cm. The micro-pore aeration disk is connected to a gas volume regulating valve, and the gas volume regulating valve is connected to a Roots blower on the edge of the earthen pond through a gas guide pipe to form an inflation device. In order to increase the circulating purification capacity of the earthen pond in the purification area, water pushing equipment (such as a waterwheel aerator) is arranged. The breeding water from the breeding area flows into the brush area, biological purification filter area, and aquatic plant purification area of the filter pond in the purification area in sequence, and finally is sent back to the breeding area by the water pushing equipment.

[0080] III. Planting submerged aquatic plants

[0081] New water is injected into the earth pond to about 0.6m, and the water inlet is filtered with a 60-80 mesh sleeve net to prevent wild fish from entering the pond. Water plants such as Hydrilla verticillata, Elodea, and Vallisneria are planted in the earth pond. The area of ​​water plants accounts for 1 / 3 to 2 / 3 of the total area of ​​the breeding area, and the purification area is 100% covered.

[0082] 4. Preparation before releasing fish

[0083] Add water to a depth of 1.0m, start the waterwheel aerator in the purification area to increase the fluidity of the water body. Release small farmed fish such as crucian carp, walleye, silver carp and bighead carp (1+ years old) in the breeding area and feed them 3 times a day to quickly improve the probiotic purification capacity of the purification area. Use timely ventilation to adjust the room temperature and control the water temperature to be above 16°C and not more than 22°C. Patrol the pond twice a day in the morning and evening to monitor water quality indicators such as water temperature, dissolved oxygen (DO), pH value, ammonia nitrogen, nitrite nitrogen, etc. When the water temperature stabilizes at 16-22°C and the ammonia nitrogen and nitrite content are within the safe limit, small shrimps can be released.

[0084] 5. Release small shrimp

[0085] Drag nets and set ground traps in the breeding area to catch fish other than silver carp and bighead carp, and purchase wild or farmed small shrimps, such as Chinese small long-armed shrimp, beautiful white shrimp, sawtooth shrimp, etc. The stocking density of shrimp fry about 1 cm is 10kg / mu. Small shrimps will scatter immediately after entering the water and hide in the water plants. A small amount of surplus should be reserved in the daily feeding amount to meet the feeding needs of small shrimps.

[0086] 6. Release of juvenile Coilia edulis

[0087] After at least 4 months of cultivation, the fry of the knife coil fish can be prepared for winter transportation when the body length reaches more than 4cm, the fish is healthy and healthy. According to the preparation of the winter solar greenhouse, the winter transportation process will start after the winter equipment is operating normally. Prepare the nets and choose summer flower nets to avoid mechanical damage to the fish body caused by large-eye nets. Remove the feeding table and stop feeding. After 24 hours, arrange workers to pull the summer flower nets to drive away the fry of the knife coil fish. The propulsion speed should not exceed 0.05m / s, and the net should be pulled for 2 minutes every 10 minutes to prevent the fry from touching the net and getting injured. The net should be close to the ground to prevent the fry from escaping. Anti-stress drugs should be put into the wintering earth pond half a day in advance to avoid stress response of the fish. The water used in the transportation process is made of artificial sea crystals or natural seawater with a salinity of 3-10‰. The fry need to be transported in basins after leaving the water and sent to the transport vehicle with water throughout the journey. They need to be counted before entering the wintering earth pond and calculated based on a water depth of 1.5m. The breeding density during the wintering period should not exceed 40,000 fry per mu.

[0088] 7. Daily operation management

[0089] ①Fish fry management

[0090] After the juvenile Coilia nasus are put into the pond, the fry adaptation period is half a month. Technical personnel need to closely monitor the survival status of the juvenile Coilia nasus and, according to the actual situation, moderately sprinkle anti-stress drugs to avoid damage to the fish body caused by stress reactions. Set 3 - 4 floating feeding areas around the earthen pond (made of φ50mm PVC plastic pipes, square floating feeding areas with a side length of 1m, well-sealed, and the floating feeding areas remain hollow to float on the water surface), put frozen cladoceran food, copepod food or frozen mantis shrimp into the floating feeding areas and let them float on the water surface to gradually domesticate the juvenile Coilia nasus to feed. After half a month, start to increase the feeding amount of the juvenile Coilia nasus, based on the gradual dispersal of the juvenile fish's feeding, and keep good feeding records to calculate the daily food intake.

[0091] ② Management of shrimp

[0092] After the small shrimps are put into the pond, they inhabit the waterweeds, pick up the remains of bait organisms and fish feces as food, clean the waterweeds and the waste residues at the bottom of the pond, and promote the secondary utilization of bait organisms. When the water temperature is appropriate, the small shrimps can carry eggs and hatch out larvae. The juvenile Coilia nasus catch the larvae to supplement their own nutrition. When the bait for the small shrimps is insufficient, appropriate amounts of formulated feed for penaeid shrimp (such as: industry standard SC / T 2002 - 2002) can be fed, with the crude protein content in the nutritional components above 42% and the crude fat content 8 - 12% to provide nutrition for the small shrimps.

[0093] ③ Management of waterweeds

[0094] Regularly check the growth of waterweeds. When the waterweeds grow wildly, they need to be harvested and cleaned in time. For floating waterweeds, remove the rotten and aging parts and keep the vigorously growing parts. For floating aquatic plants such as duckweed and water hyacinth, tow them to the shore with floating ropes to ensure that the covered water surface area does not exceed 50%. The coverage area of submerged waterweeds at the bottom of the pond should not exceed 60%. If they grow wildly to the water surface, they should be cut off in time to avoid occupying the water space. Drag the harvested waterweeds to the shore and do not place them in the water to rot and pollute the water.

[0095] ④ Management of the purification area

[0096] The water-pushing equipment in the purification area needs to run 24 hours a day. The aeration equipment always pushes the biological purification filter sheets to float in the filter tank. The waterweeds in the filter tank in the purification area are planted to reach 100%, but it is necessary to prevent them from growing too high. When they reach the water surface height, they need to be cut off in time to maintain the water permeability. Measure the water quality indicators entering and leaving the purification area every morning and evening to ensure that indicators such as ammonium nitrogen and nitrite nitrogen meet the growth requirements of the cultured organisms.

[0097] ⑤ Maintenance of equipment

[0098] Regularly check the operating status of standby fans and water-pushing equipment to ensure the stable operation of the equipment. Ensure the dryness of the thermal insulation layer on the top of the solar greenhouse (such as: straw curtains, felts, and thermal insulation cotton quilts) and the stable operation of the rolling machine. Adjust the air supply intensity of the aeration facilities in the aquaculture area in a timely manner to avoid stress reactions of aquaculture organisms caused by human operation.

[0099] ⑥ Maintenance in rain, snow, etc.

[0100] Arrange for special personnel to be on duty in winter. Especially in the case of strong winds, rain, snow, or other bad weather at night, additional personnel should be dispatched in a timely manner to ensure the integrity of the structure of the solar greenhouse. Clean the snow on the surface of the greenhouse at any time, and operate the rolling machine for heat preservation according to the weather conditions.

[0101] VIII. Harvest

[0102] ① Harvest of Coilia nasus

[0103] Turn off the water-pushing equipment in the purification area, take out the microporous aeration discs and floating feeding areas in the aquaculture area, and arrange the floating aquatic plants on the water surface of the aquaculture area. Then, workers can be arranged to prepare for the net-pulling operation. The net-pulling steps are the same as those of the above-mentioned net-pulling method for earthen ponds. Slowly and evenly capture the juvenile Coilia nasus with water, and transport them with water to the outside or arrange for market sales.

[0104] ② Harvest of small shrimps

[0105] Adopt the method of capturing with a ground cage. Place bait in the ground cage to attract small shrimps into the cage. Transport them by dry method or arrange for market sales.

[0106] The results of the examples show that the present invention adopts multiple key links such as the principle of mixed culture of fish, shrimps, and grass, transformation of hardware facilities, planting and maintenance of grass, release and cultivation of shrimps, transportation, release, and cultivation of fish, etc., for the overwintering cultivation of juvenile Coilia nasus. It can effectively improve the overwintering survival rate of juvenile Coilia nasus and is a complete and efficient method for overwintering cultivation of juvenile Coilia nasus. The overwintering cultivation method of the present invention is an effective way to solve the problem of overwintering Coilia nasus under artificial conditions in the northern region, greatly reducing the cost of overwintering Coilia nasus in earthen ponds, reducing the overwintering risk, and improving the overwintering success rate.

Claims

1. A method for overwintering and cultivating juvenile Coilia nasus in a solar greenhouse in the northern region, characterized in that, The specific process is as follows: (1) Cultivation of juvenile Coilia otarius before wintering Before the wintering, the fry of Coilia lanceolata has gone through the stages of fertilized egg hatching and fry cultivation, and its body length has reached more than 7 cm, it is disease-free and uninjured, and it feeds on live bait organisms; when the outdoor water temperature is 15-17℃, it is transferred to the solar greenhouse of the cultivation system for wintering cultivation; (2) Renovation of soil ponds in solar greenhouse Select a 2-4 mu earth pond with a length-width ratio of 8-10:1, drain the pond water, and dry it in the sun for 20-40 days; remove the silt at the bottom of the pond and compact the pond bottom with tools; backfill part of the original pond bottom sludge to restore some functions of the pond bottom and loosen the soil to prepare for planting aquatic plants; divide the breeding area and purification area into functional zones, lay microporous oxygenating plates at the bottom of the breeding area, and lay filter tanks and water pushing equipment in the purification area. The breeding water from the breeding area passes through the filter tank in the purification area and is sent back to the breeding area by the water pushing equipment; (3) Planting of submerged aquatic plants Water is added to the earth pond to a depth of 0.5 to 0.7 m, and the water inlet is filtered with a 60-80 mesh sleeve net to prevent wild fish from entering the pond; aquatic plants are planted in the earth pond, and the area of ​​aquatic plants accounts for 1 / 3 to 2 / 3 of the total area of ​​the breeding area, and the purification area is 100% covered; (4) Preparation before releasing fish Add water to a depth of 1.0m, start the water pusher in the purification area to increase water mobility; put small farmed fish in the breeding area and feed them three times a day to quickly improve the probiotic purification capacity of the purification area; use ventilation to adjust the room temperature and control the water temperature to be above 16℃ and not more than 22℃; patrol the pond twice a day in the morning and evening to monitor water quality indicators. If the water quality indicators are within the safety limit, put small shrimp; (5) Release small shrimp Drag nets and set ground traps in the breeding area to catch small farmed fish, and purchase wild or farmed small shrimps; the density of shrimp fry with a body length of 0.8 to 1.2 cm is 8 to 12 kg per mu. After entering the water, the small shrimps immediately scatter and hide in the water plants; (6) Release of juvenile Coilia edulis After at least 4 months of cultivation, the fry of Coilia lanceolata, which is over 4cm in length, free of disease and injury, and in good physical condition, are prepared for winter transportation. According to the preparation of the solar greenhouse for wintering, the winter transportation process will begin after the wintering equipment is operating normally. Prepare the nets, choose summer nets, and after stopping feeding for 24 hours, place the summer nets close to the ground and pull the summer nets to drive away the fry of Coilia lanceolata. The propulsion speed should not exceed 0.05m / s, and pause for 2 minutes every 10 minutes of pulling the nets. (7) Daily operation management, including fish fry management, shrimp management, grass management, purification area management, equipment maintenance and rain and snow maintenance; (8) Harvesting, including harvesting of razor-sharp anchovies and small shrimps.

2. The overwintering cultivation method of Coilia nasus juvenile fish in solar greenhouse in the northern region according to claim 1, characterized in that In step (1), the cultivation system is composed of a solar greenhouse and an earthen pond inside the solar greenhouse. The support frame of the solar greenhouse is divided into a second structural support member on the sunny side and a first structural support member on the shady side. The first structural support member and the second structural support member are inclined to form a "human"-shaped support frame. A sieve net is vertically installed at three-fourths of the area along the length direction of the earthen pond, dividing the earthen pond into two areas. Three-fourths is the breeding area, and one-fourth is the purification area. Among them, a microporous aeration disk is laid at the bottom of the breeding area, and a submerged plant planting area is arranged between two adjacent rows of microporous aeration disks. The microporous aeration disks are evenly distributed at the bottom of the earthen pond on both sides of the submerged plant planting area. A waterwheel aerator is installed in the purification area as a water-pushing device. The waterwheel aerator is separated by a partition net and is located at a corner of the purification area.

3. The overwintering cultivation method of Coilia nasus juveniles in solar greenhouses in the northern region according to claim 1, characterized in that, In step (2), when the soil at the bottom of the earthen pond is loose and prone to leakage, the bottom of the pond should be dug deeper, and the thickness of the water barrier layer should be increased by using clay backfill. The microporous aeration disk is a coiled nano-aeration tube with a diameter of 50 - 100 cm. The microporous aeration disk is connected to a gas volume regulating valve, and the gas volume regulating valve is connected to a Roots blower on the edge of the earthen pond through a gas pipe to form an inflation device. The breeding water from the breeding area flows into the brush area, biological purification filter area, and aquatic plant purification area of the filter pond in the purification area in sequence, and then is sent back to the breeding area by the water-pushing device.

4. The overwintering cultivation method of Coilia nasus juvenile fish in solar greenhouse in the northern region according to claim 1, characterized in that, In step (3), the aquatic plants are one or more of Hydrilla verticillata, Elodea nuttallii, and Vallisneria natans.

5. The method for overwintering cultivation of Coilia nasus juveniles in a solar greenhouse in the northern region according to claim 1, characterized in that, In step (4), the small breeding fish are one or more of crucian carp, Leuciscus waleckii, and silver carp and bighead carp over one year old. The water quality indicators include water temperature, dissolved oxygen, pH value, ammonia nitrogen, and nitrite nitrogen. When the water temperature is stable at 16 - 22 °C and the contents of ammonia nitrogen and nitrite are within the safety limit, small shrimps are put in.

6. The method for overwintering and culturing juvenile Coilia nasus in a solar greenhouse in the northern region according to claim 5, characterized in that, In step (5), a net is pulled in the breeding area and combined with setting up ground cages to catch other fish except silver carp and bighead carp. The small shrimps are one or more of Palaemonetes sinensis, Palaemon modestus, and Caridina denticulata. A small amount of surplus should be reserved for the daily feeding amount to meet the feeding needs of small shrimps.

7. The method for overwintering and cultivating juvenile Coilia nasus in a solar greenhouse in the northern region according to claim 1, characterized in that, In step (6), anti-stress drugs should be put into the overwintering earthen pond 1 h in advance to avoid stress reaction of fish bodies. The water used in the transportation process is modulated from artificial seawater crystal or natural seawater to a salinity of 3 - 10‰. The fry should be transported in a basin when they leave the water, and they should be sent into the transport vehicle with water all the way. They need to be counted before entering the overwintering earthen pond, and the cultivation density during the overwintering period should not exceed 40,000 tails per mu.

8. The method for overwintering cultivation of Coilia nasus juvenile fish in solar greenhouse in the northern region according to claim 1, characterized in that, In step (7): ① Fry management After the Coilia nasus juveniles enter the pond, the fry adaptation period is half a month. Closely monitor the survival status of the Coilia nasus juveniles, and sprinkle anti-stress drugs according to the actual situation to avoid damage to the fish bodies caused by stress reaction. The floating feeding area is made of a φ50 mm PVC plastic pipe and is a square floating feeding area with a side length of 1 m. Sealing treatment should be done well, and the floating feeding area should keep floating on the water surface. Set 3 - 4 floating feeding areas around the earthen pond, put frozen cladoceran food, copepod food, or frozen mantis shrimp into the floating feeding areas and let them float on the water surface to gradually domesticate the Coilia nasus fry to feed. After half a month, gradually increase the feeding amount of the Coilia nasus juveniles until the fry gradually disperse after feeding, and do a good job in feeding records and calculate the daily food intake. ② Management of Shrimp After small shrimp are put into the pond, they inhabit the waterweeds, pick up the remains of bait organisms and fish feces as food, clean the waterweeds and waste residues at the bottom of the pond, and promote the secondary utilization of bait organisms; small shrimp carry eggs and hatch larvae, which are captured by Coilia nasus juveniles to supplement their own nutrition; when the bait for small shrimp is insufficient, penaeid shrimp compound feed is fed, with the crude protein content in the nutrient components above 42% and the crude fat content 8-12%, providing nutrition for small shrimp. ③ Management of Waterweeds Regularly check the growth of waterweeds. When the waterweeds grow wildly, they need to be harvested and cleaned in time; for floating waterweeds, the rotten and aging parts are fished out, and the vigorously growing parts are reserved; for floating aquatic plants such as duckweed and water hyacinth, they are towed to the shore with floating ropes to ensure that the covered water surface area does not exceed 50%; the coverage area of submerged waterweeds at the bottom of the pond does not exceed 60%. If they grow wildly to the water surface, they should be cut off in time to avoid occupying the water space, and the harvested waterweeds are towed to the shore. ④ Management of the Purification Area The water-pushing equipment in the purification area needs to operate 24 hours a day, and the aeration equipment always pushes the biological purification filter discs to float in the filter pond; the planting area of waterweeds in the filter pond in the purification area reaches 100%, but it is necessary to prevent them from growing too high; when they reach the water surface height, they need to be cut off in time to maintain the water permeability; measure the water quality indicators entering and leaving the purification area every morning and evening to ensure that the ammonium nitrogen and nitrite nitrogen indicators meet the growth requirements of aquaculture organisms. ⑤ Maintenance of Equipment Regularly check the operation status of standby fans and water-pushing equipment to ensure the stable operation of the equipment; ensure the dryness of the thermal insulation layer on the top of the solar greenhouse and the stable operation of the rolling machine, and timely adjust the air supply strength of the aeration facilities in the aquaculture area to avoid stress reactions of aquaculture organisms caused by human operation. ⑥ Maintenance in Rain and Snow In winter, ensure the integrity of the structure of the solar greenhouse, clean the snow on the surface of the greenhouse at any time, and operate the rolling machine to keep warm according to the weather conditions.

9. The method for overwintering and cultivating juveniles of Coilia nasus in a solar greenhouse in the northern region according to claim 1, characterized in that, In step (8): ① Harvest of Coilia nasus Turn off the water-pushing equipment in the purification area, take out the microporous aeration discs and floating feeding areas in the aquaculture area, arrange the floating waterweeds on the water surface of the aquaculture area, and arrange workers to prepare for the netting operation; the netting steps are the same as the above-mentioned netting method for earthen ponds, and the Coilia nasus juveniles are captured with water slowly and evenly, and transported with water to the outside. ② Harvest of Small Shrimp Adopt the method of capturing with a ground cage. Place bait in the ground cage to attract small shrimp into the cage.

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