A method for culturing coilia nasus fry in wintering period in north region

Abstract

The present application relates to the field of Coilia ectenes fry cultivation, in particular to a kind of northern region Coilia ectenes fry overwintering period cultivation method.The method includes: outdoor soil pond fattening, biological bait culture, indoor overwintering workshop seawater overwintering, fry recovery and maturation after overwintering period.Adopting outdoor soil pond cultivation mode, combined with live bait culture and feeding technology, Coilia ectenes fry is fattened in short time to meet the nutritional reserves in overwintering period.In early overwintering period, through salinity control technology, Coilia ectenes fry is adapted to the environment of salinity change in short time to meet the demand of Coilia ectenes fry on environmental osmotic pressure in overwintering period.In mid overwintering period, seawater overwintering workshop technology is used to maintain water temperature and salinity smooth transition.In late overwintering period, temperature rising and biological bait induction are used to help Coilia ectenes fry recover rapidly, promote fry to transition to reserve broodstock stage, and thus solve the overwintering problem of Coilia ectenes in northern region, which can effectively improve the survival rate of Coilia ectenes fry in overwintering period and improve the recovery speed of Coilia ectenes fry after overwintering.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of Coilia nasus fry culture, in particular to a Coilia nasus fry overwintering culture method in northern areas. BACKGROUND

[0002] Coilia nasus is a fish of Engraulidae and Coilia. The body is silver white. The back side is darker in color, being cyan, golden yellow or cyan yellow. The abdomen is lighter in color. The tail fin is gray. Because of the custom of eating Coilia nasus before the morning in Shanghai, and the extremely small amount of capture, Coilia nasus was once called a fish with a high price, a ten-thousand-yuan fish. Due to the overfishing of humans, Coilia nasus also once faced population extinction. The number of Coilia nasus population in the Yangtze River Estuary has been decreasing year by year, and Coilia nasus was included in the Red List of Endangered Species of the World Conservation Union in 2017.

[0003] Coilia nasus feeds on plankton and live fish and shrimp in the natural environment, which causes great difficulty to artificial propagation and fry culture. Coilia nasus has strong stress resistance, and dies after being taken out of the water in natural water bodies, so the stress problem in the process of Coilia nasus culture is one of the difficulties in technical research. Coilia nasus needs to go through a long overwintering period under the breeding conditions in the north, which puts high requirements on the nutrition reserve, wound repair, water quality control and feed supply of fry. Because of the above reasons, the breeding and fry culture of Coilia nasus have been difficult to break through. SUMMARY

[0004] In view of the above problems, the present application aims to provide a Coilia nasus fry overwintering culture method in northern areas, which can effectively improve the overwintering success rate of Coilia nasus in northern areas.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A Coilia nasus fry overwintering culture method in northern areas, the specific process is as follows:

[0007] (1) Feed fry culture

[0008] According to 10,000 Coilia nasus fry 10,000 kg of mature parent fish of Pseudobagrus fulvidraco, the density is controlled to be 3,000 kg per mu during temporary culture, and the development of gonads is controlled. The artificial feed used in this stage should ensure that the crude protein content is more than 42 wt%, and the crude fat content is 8-12 wt%, meeting the requirements of gonadal development;

[0009] (2) Coilia nasus fry outdoor soil pond culture

[0010] The knife herring fry needs 30-45 days from the breaking of the egg membrane to the body length reaching 3-5 cm; at this time, the knife herring fry has been transferred to the outdoor soil pond for cultivation, and the soil pond live plankton feed is cultivated by using the conventional bait biological culture method before the fish fry is put into the pond; the plankton in the soil pond is qualitatively and quantitatively determined every day after the fish fry is put into the pond to ensure that the bait supply can meet the feeding needs of the knife herring fry; the live bait feeding system dedicated to the cultivation of the knife herring fry is set in the soil pond, and the sexually mature wild and miscellaneous parent fish are continuously supplemented into the bait feeding system to ensure the normal operation of the system;

[0011] After the fish fry is put into the soil pond for 30 days, the acclimation of the frozen biological bait is started; under the condition of the live bait organisms in the soil pond, the frozen biological bait is cut into 500 g blocks and is put on the upwind side of the soil pond in the morning on sunny days; the bait organisms are added in the order of rotifer-brine shrimp-frozen biological bait-live fish fry-artificial compound feed; after the soil pond is cultivated for three months, the body length of the knife herring fry reaches more than 20 cm, the body shape is uniform, and there is no disease or injury, and the knife herring fry is transferred to the pre-transport preparation stage;

[0012] ①Preparation of the soil pond before transport

[0013] The summer-flowering net is used for purse seining operation to drive the fish fry to one side of the pond, and the rice straw bundles are inserted at the bottom of the net every 50 cm, and the diameter of the rice straw bundle is 6 cm; the net is not inserted into the bottom mud too deep, and the depth is preferably 5 cm; the pushing speed of the net is not more than 0.5 m / s, and the net is fixed; the oxygenation machine is erected on the side of the pond without knife herring fry, and one fifth of the original pond water is drained; the seawater with a salinity of not less than 20 ‰ is injected, and the oxygenation machine is turned on for more than 12 hours; the purse net is released, and the probiotic bacteria are added to adjust the water quality;

[0014] ②Preparation of the overwintering workshop before transport

[0015] The pond water is drained, and the pond is disinfected; the natural seawater filtered by sand is injected, and the average water level is controlled at 50 cm; all the doors and windows of the overwintering workshop are opened to maintain ventilation; the temperature difference between the outdoor soil pond and the cement pool in the overwintering workshop is monitored in a timely manner;

[0016] ③Transport of the fish fry

[0017] When the following conditions are met: the water temperature difference between the outdoor soil pond and the cement pond in the wintering workshop is less than 2℃, the outdoor soil pond is added with seawater for more than 5 days, and the fish fry transportation work starts; choose sunny morning, use summer flower net to pull the net in the whole pond, the net advancing speed is not more than 0.5m / s; the bottom of the net is inserted with straw bundle, every 50cm a bundle, the diameter of the straw bundle is 6cm, the net lower edge is not inserted into the bottom mud too deep, 5cm is appropriate; the fish fry is driven to one corner of the pond with the net, the range is gradually reduced, the water depth in the net is maintained at 30cm, and the state of the knife gizzard shad fry in the net is observed, whether there is net sticking or not, at the same time, the water flow is stirred to increase the water body dissolved oxygen; a half pond water is put into a container with a diameter of more than 15cm, and the water is transported with the fry, the density of the knife gizzard shad fry in the container is not more than 2 tails per liter of water; the fry is quickly transported to the cement pond in the wintering workshop, the container bottom is placed in the water, then the container is poured, and the fry is smoothly slid into the pond;

[0018] (3) Wintering in the wintering workshop

[0019] The area of the wintering workshop is appropriate to be two mu, the top is of single-sided light transmission type, and the highest point is located above the cement pond at 4 / 5 of the horizontal position; a straw curtain is arranged at the highest point of the top, and a roller blind reducer is arranged to lower the straw curtain before night to keep warm; the wintering workshop is appropriate to be a cement pond, the pond wall is made of slope protection to prevent soil sliding, and the bottom mud is cleaned in time before winter, with a thickness of not more than 20cm; the circulating water treatment unit is kept open for 24h during the wintering period, the pond water is always in a state of micro-flow, and the water temperature is maintained above 7℃ in winter, which can meet the water temperature and quality requirements of knife gizzard shad during the wintering period;

[0020] After the fry is put into the pond, the doors and windows of the wintering workshop are closed, the circulating water treatment unit is started 7 days in advance, and probiotics are inoculated into the biological filter;

[0021] (4) Start the live bait feeding system

[0022] The live bait feeding system is arranged in the pond, the interval between the single live bait feeding systems is 5-10m, the procambarus clarkii or the procambarus clarkii ovigerous shrimp is put into the live bait feeding system, and the inflation device of the live bait feeding system is started; after hatching and culture, the live bait feeding system will automatically put the newly hatched shrimp into the water body to provide food for the knife gizzard shad fry.

[0023] The northern knife gizzard shad fry wintering period cultivation method, in step (1), the flow rate is controlled, except for the necessary oxygenation of the oxygenator, water supply and drainage operations are avoided, and the water quality control link adopts the method of micro-ecological preparation to stabilize the water quality and the bottom.

[0024] The artificial breeding method of the juvenile Coilia ectenes in the northern region during the overwintering period, in step (1), the artificial mixed feed formula for the temporary breeding of the sexually mature parent fish is as follows: fish meal 31%, meat powder 6%, soybean meal 15%, rapeseed meal 5%, flour 16%, marine feed premix 5%, fish oil 2%, soybean oil 3%, rice bran 11%, vinasse 3%, corn gluten meal 3%, and the expanded slow-sinking feed is made into granules with a particle size of 1.2 mm, 1.5 mm or 2.0 mm.

[0025] The artificial breeding method of the juvenile Coilia ectenes in the northern region during the overwintering period, in step (1), the environmental conditions are controlled, the breeding density is increased, the water flow rate is controlled, and the nutritional conditions of the bait fish parent fish are strengthened to promote the development of the gonads of the bait fish parent fish to stage IV and keep them at stage IV.

[0026] The artificial breeding method of the juvenile Coilia ectenes in the northern region during the overwintering period, in step (2), the frozen biological bait is purchased as a commercial frozen plate, or the plankton is cultured in an idle pond and then frozen for standby after being filtered.

[0027] The artificial breeding method of the juvenile Coilia ectenes in the northern region during the overwintering period, in step (3), the overwintering workshop structure is divided into a cement pool, a heat preservation wall and a ceiling, the cement pool is provided with five layers of fillers, and the fillers are arranged from bottom to top and from outside to inside of the pool wall as follows: large stone layer, gravel layer, sandy soil layer, polystyrene board and concrete layer; a circulating water treatment unit is arranged at a corner of the cement pool, and the circulating water treatment unit comprises a primary filtration biological reaction filter tank, a secondary biological reaction filter tank, an ultraviolet reaction tank and an aeration heating tank which are sequentially connected; the heat preservation wall is built on the embankment around the top of the cement pool, and the ceiling is installed on the top of the heat preservation wall.

[0028] The artificial breeding method of the juvenile Coilia ectenes in the northern region during the overwintering period, the angle between the pool wall and the pool bottom is 135-150°, and the cement pool is formed by hardening treatment of the concrete layer.

[0029] The artificial breeding method of the juvenile Coilia ectenes in the northern region during the overwintering period, in step (4), the upper frame body, the acrylic support plate and the lower frame body of the live bait feeding system are coaxially arranged from top to bottom and connected, the upper frame body is a cylindrical stainless steel frame, the box surrounded by the 40-mesh nylon screen silk net is covered on the outer side of the upper frame body, the upper part of the box is a lid, the bottom of the box is a fish separation net, and the top of the side of the box is tied with a float; the middle part is a ring-shaped disc-shaped acrylic support plate, which is located below the fish separation net; the lower frame body is a cylindrical stainless steel frame, the fish outlet net surrounded by the 5-mesh nylon screen silk net is covered on the outer side of the upper part of the lower frame body, and the egg collection bag surrounded by the nylon screen silk net is covered on the outer side and the bottom of the lower part of the lower frame body, and the disc-shaped microporous oxygenation pipe is hung at the bottom of the egg collection bag.

[0030] The bottom of the egg bag is provided with a disc-shaped microporous oxygen-increasing pipe, the microporous oxygen-increasing pipe is a disc-shaped oxygen-increasing pipe, the diameter of the disc-shaped oxygen-increasing pipe is 80 cm, the microporous oxygen-increasing pipe is connected with a gas amount adjusting valve, the gas amount adjusting valve is connected with a Roots blower at the edge of the pond to form an aeration device.

[0031] The live bait feeding system is arranged in the water body and stands in the water layer in a hanging manner, and the bottom aeration device is started to operate the live bait feeding system; mature wild and miscellaneous fish parent fish are supplemented to the live bait feeding system in the outdoor earth pond cultivation link, and the proglottid white prawn or Chinese small long-armed prawn is supplemented to the live bait feeding system during the overwintering period, and the above-mentioned organisms are fed in a timely manner, that is, the live bait fish or prawn larvae are continuously supplemented and fed to the water body to supplement the nutritional requirements of the knife gizzard shad fry at different stages.

[0032] The design idea of the present application is:

[0033] The method comprises outdoor earth pond fattening, biological bait culture, indoor overwintering workshop seawater overwintering, fry recovery and maturation promotion after overwintering, adopts the outdoor earth pond cultivation mode, combines live bait culture and feeding technology, and fattens the knife gizzard shad fry in a short time to meet the nutritional reserve during the overwintering period. The salinity regulation technology is used before overwintering to make the knife gizzard shad fry adapt to the environment with salinity change in a short time to meet the demand of the knife gizzard shad fry for environmental osmotic pressure during the overwintering period. The seawater overwintering workshop technology is used in the middle period of overwintering to maintain the stable transition of water temperature and salinity. The temperature rising and biological bait induction are used in the late overwintering period to help the knife gizzard shad fry quickly recover the physical condition, promote the transition of the fry to the parent fish stage, and thus solve the overwintering problem of the knife gizzard shad in the northern region. The present application can effectively improve the overwintering survival rate of the knife gizzard shad fry and the recovery speed of the knife gizzard shad fry after overwintering, improve the disease resistance of the fish body, and is a complete and efficient overwintering period cultivation method for the knife gizzard shad fry in the northern region.

[0034] In addition, the overwintering workshop roof of the present application adopts one-side light transmission, utilizes sunlight for heating, and maintains the water temperature at night. The self-circulating water treatment unit of the overwintering workshop is used to solve the water temperature and water quality problems of the knife gizzard shad in the northern region during the overwintering period. The overwintering workshop structure is composed of a cement pool, an insulation wall and a roof, the pool bottom of the cement pool is made of multiple layers of material and is hardened by a concrete layer. The circulating water treatment unit is constructed by pouring concrete in the northwest corner of the cement pool. The circulating water treatment unit is provided with a primary filtration biological reaction filter tank, a secondary biological reaction filter tank, an ultraviolet reaction tank and an aeration heating tank. The present application can meet the environmental conditions of the knife gizzard shad fry during the overwintering period, reduce the input of fossil fuels, improve the overwintering survival rate, and reduce manual operation.

[0035] Also, the live bait feeding system for coilia ectenes fry breeding is designed according to the breeding characteristics of the bait fish, adopts a stainless steel frame and an acrylic plate as supporting materials, and is made of nylon screen nets with different densities. According to the bait demand of coilia ectenes fry breeding, a certain amount of bait fish spawning parent fish is regularly put into the box, and spawns under the stimulation of the micro-flow water caused by the bottom micropore oxygenation. The spawned fertilized eggs fall into the lower egg collecting bag under the action of gravity, and are hatched in the water under the action of the bubbles of the micropore oxygenation pipe. After the bait fish fry is hatched, it will move horizontally and vertically with the increase of its swimming ability, swim out of the fish net aperture to the outside of the system, and the coilia ectenes will capture the bait fish fry to achieve the feeding purpose.

[0036] The present application has the following advantages and beneficial effects:

[0037] (1) The present application is suitable for coilia ectenes breeding and artificial breeding in northern China. The wintering period in northern China is long, for example, the pond ice sealing period in the eastern region of Liaoning Province usually lasts more than 5 months, the temperature is low, and the minimum temperature is as low as minus 20 DEG C. Artificially bred coilia ectenes cannot survive in such natural conditions. The present application provides a feasible solution for coilia ectenes fry overwintering breeding under artificial conditions in northern China.

[0038] (2) The present application controls the environmental conditions, increases the breeding density, controls the flow rate, and at the same time strengthens the nutritional conditions of the bait fish parent fish (mylopharyngodon piceus), a series of processes, promotes the development of the gonad of the bait fish parent fish (mylopharyngodon piceus) to the IV stage and stays in the IV stage, and does not transition to the V stage, so as to meet the needs of coilia ectenes to have sufficient bait supply in only three months of fattening period.

[0039] (3) The present application improves the net tool, so that the net has good driving effect in the operation process, does not bring too much silt, reduces the mechanical damage of coilia ectenes fry in daily operation and capture, avoids the crushing damage to the retained fry, reduces the workload caused by fish body repair in the later period, and improves the survival rate of fry breeding period. The two-net capture rate is more than 85%, and the fry damage is small and can be ignored.

[0040] (4) According to the actual needs of coilia ectenes overwintering, the traditional earth pond is transformed, the pond bottom heat preservation structure is improved, and the circulating water treatment unit is designed to replace the traditional earth pond to utilize the bottom mud exchange metabolites, so as to create stable environmental conditions for coilia ectenes fry overwintering.

[0041] (5) The present application improves the conventional circulating water starting process, effectively solves the damage of coilia ectenes fry caused by the transfer of the net, and the problem of unreasonable recovery caused by the bacterial flora of the pond water, and the success rate of fry transfer is improved by more than 30%.

[0042] (6) The present application sets up a live bait feeding system for knife gizzard shad fry cultivation in the breeding water body, which is suspended in the water layer and can be operated by starting the bottom air charging device. In the outdoor soil pond cultivation link, mature wild and miscellaneous fish parent fish are supplemented into the live bait feeding system, and during the wintering period, the brood of Procambarus clarkii or Caridina nilotica is supplemented into the live bait feeding system, and the above-mentioned organisms are fed regularly, so that the live bait fish (shrimp) larvae can be continuously supplemented and fed into the water body to meet the nutritional needs of the knife gizzard shad fry at different stages.

[0043] (7) The present application adjusts the water body salinity during the wintering period, and then adjusts the osmotic pressure in the body of the knife gizzard shad, helping the knife gizzard shad to successfully pass through the wintering period. While adjusting the water body salinity during the wintering period, the speed and rhythm of increasing the salinity are specified, which greatly improves the wintering success rate of the knife gizzard shad fry under the condition that the ice sealing period in the northern region is long, and ensures that the survival rate of the knife gizzard shad reaches more than 95% during the process of increasing the salinity.

[0044] (8) In the case that the ice sealing period in the north lasts for 5 months, by gradually increasing the water body salinity and stabilizing it at about 8‰, the wintering survival rate of the knife gizzard shad fry can be increased from 0 to more than 80%. BRIEF DESCRIPTION OF DRAWINGS

[0045] Fig. 1 It is a side view of the wintering workshop special for knife gizzard shad fry cultivation.

[0046] Fig. 2 It is a bird's eye view of the wintering workshop special for knife gizzard shad fry cultivation.

[0047] Figs. 1-2 In the figure, 1 is a roller shutter speed reducer, 2 is a ceiling (21 is a light transmission side, and 22 is a light blocking side), 3 is a heat preservation wall, 4 is a door and window, 5 is a dike, 6 is a cement pool, 7 is a filler layer (71 is a large stone layer, 72 is a gravel layer, 73 is a sandy soil layer, 74 is a polystyrene board, and 75 is a concrete layer), 8 is a primary filtering biological reaction filter tank (81 is a filtering brush), 9 is a secondary biological reaction filter tank (91 is a biochemical filter ball), 10 is an aeration heating tank (101 is a water pump), 11 is a water outlet pipe, 12 is an ultraviolet reaction tank (121 is a UV sterilizer), and 13 is a straw mat.

[0048] Fig. 3 It is a side view of the live bait feeding system special for knife gizzard shad fry cultivation.

[0049] Fig. 4 It is an upper view of the live bait feeding system special for knife gizzard shad fry cultivation.

[0050] Fig. 5 It is a lower view of the live bait feeding system special for knife gizzard shad fry cultivation.

[0051] Figs. 3-5 In, 1401, float, 1402, cover, 1403, upper frame body, 1404, box, 1405, acrylic support plate, 1406, fish net, 1407, lower frame body, 1408, egg collection bag, 1409, microporous oxygenation tube, 1410, fish separation net. DETAILED DESCRIPTION

[0052] As Figs. 1-2 shown, the application proposes a overwintering workshop special for coilia ectenes fry cultivation, mainly comprising: roller shutter speed reducer 1, ceiling 2, heat preservation wall 3, door and window 4, dike 5, cement pool 6, filler layer 7, primary filtration biological reaction filter 8, secondary biological reaction filter 9, aeration heating pool 10, water outlet pipe 11, ultraviolet reaction pool 12, straw baffle 13 and the like, the specific structure is as follows:

[0053] The cement pool 6 is provided with five filler layers 7 in the pond, the filler layers 7 are provided with large stone layer 71 (the particle size of the large stone is 60-80mm), gravel layer 72, sandy soil layer 73, polystyrene plate 74 and concrete layer 75 from bottom to top and from outside to inside of the pond wall, the included angle between the pond wall and the pond bottom is 135-150°, the concrete layer is hardened to form the cement pool 6, the size of the pond bottom of the cement pool 6 is 70m*20m*2m. Through the reconstruction of the pond bottom of the cement pool, the large stone layer, gravel layer, sandy soil layer, polystyrene plate and concrete layer are additionally paved to form a multi-layer structure, which has the effects of heat preservation, anti-seepage and anti-landslide.

[0054] The northwest corner in the cement pool 6 is constructed by pouring concrete to build a circulating water treatment unit. The circulating water treatment unit is provided with primary filtration biological reaction filter 8, secondary biological reaction filter 9, ultraviolet reaction pool 12 and aeration heating pool 10 which are sequentially communicated, the inlet of the primary filtration biological reaction filter 8 is communicated with the cement pool 6, the breeding wastewater enters the primary filtration biological reaction filter 8 through the inlet, the filtration brush 81 is arranged in the primary filtration biological reaction filter 8, the biochemical filter ball 91 is arranged in the secondary biological reaction filter 9, the UV sterilizer 121 is arranged in the ultraviolet reaction pool 12, the water pump 101 is arranged in the aeration heating pool 10, the water outlet pipe 11 of the water pump 101 is communicated with the cement pool 6, the breeding wastewater is circulated after being treated by the circulating water treatment and then enters the cement pool 6 for circulation, the breeding wastewater is treated by the circulating water treatment, which can reduce the labor cost and realize zero discharge of wastewater during the overwintering period.

[0055] The heat insulation wall 3 is built on the embankment 5 around the top of the cement pool 6, and doors and windows 4 are arranged on the heat insulation wall 3; the top of the heat insulation wall 3 is provided with a ceiling 2, the ceiling 2 is of a single-side light-transmitting type, the highest point of the ceiling 2 is located at a position of about 4 / 5 of the cement pool in the horizontal direction, and the side corresponding to the south direction is the light-transmitting side 21, and the other sides are the light-blocking sides 22. A roller shutter speed reducer 1 is arranged at the highest point of the ceiling 2, and a straw curtain 13 is arranged on the roller shutter speed reducer 1, and the straw curtain 13 is lowered to keep warm before night.

[0056] In use, the conventional circulating water starting process is improved, low-temperature bacterial species are screened and cultured, and the primary filtration biological reaction filter tank and the secondary biological reaction filter tank are put in 7 days in advance. Through the internal small circulation system, the number of bacterial population is amplified in a short time. The stress resistance of knife sardines is extremely poor, and the mortality rate of knife sardines is more than 50% when they are separated from water and attached to the net. In view of the special constitution of knife sardines, the improved process effectively solves the problems of damage of knife sardine fry caused by the transfer of the purse seine and the difficulty of recovery caused by unreasonable bacterial population in the pool water, and the success rate of fry transfer is increased by more than 30%.

[0057] As shown in Figs. 3-5 The present application provides a live bait feeding system special for knife sardine fry cultivation, which mainly comprises: a float 1401, a cover 1402, an upper frame body 1403, a box 1404, a plexiglass support plate 1405, a fish outlet net 1406, a lower frame body 1407, an egg collecting bag 1408, a microporous oxygenation pipe 1409, a fish separating net 1410, and the like, and the specific structure is as follows:

[0058] The upper frame body 1403 is a cylindrical stainless steel frame, the box 1404 is surrounded by a 40-mesh nylon screen gauze net covering the outer side of the upper frame body 1403, the upper part of the box 1404 is the cover 1402, the bottom of the box 1404 is the fish separating net 1410, and the float 1401 is tied to the top of the side surface of the box 1404; the middle part is a ring-shaped disc-shaped plexiglass support plate 1405, which is located below the fish separating net 1410; the lower frame body 1407 is a cylindrical stainless steel frame, the fish outlet net 1406 is surrounded by a 5-mesh nylon screen gauze net covering the outer side of the upper part of the lower frame body 1407, and the egg collecting bag 1408 is surrounded by a 40-mesh nylon screen gauze net covering the outer side and the bottom of the lower part of the lower frame body 1407, and the disc-shaped microporous oxygenation pipe 1409 is hung at the bottom of the egg collecting bag 1408.

[0059] The upper frame body 1403, the acrylic supporting plate 1405 and the lower frame body 1407 are coaxially arranged from top to bottom and connected, the upper end of the acrylic supporting plate 1405 is connected with the lower end of the box 1404, the lower end of the acrylic supporting plate 1405 is connected with the top end of the fish outlet net 1406, the diameter of the upper end of the acrylic supporting plate 1405 is the same as that of the upper frame body 1403, and the diameter of the lower end of the acrylic supporting plate 1405 is the same as that of the lower frame body 1407.

[0060] The upper frame body 1403 is made of stainless steel and has a cylindrical shape with a diameter of 200 cm and a height of 100 cm.

[0061] The acrylic supporting plate 1405 is made of smooth plastic material and has a ring-shaped three-dimensional structure with an upper end diameter of 200 cm, a lower end diameter of 100 cm and a height of 20 cm.

[0062] The lower frame body 1407 is made of stainless steel and has a cylindrical shape with a diameter of 100 cm and a height of 60 cm.

[0063] The cover 1402 and the box 1404 are made of 40-mesh nylon screen gauze, the cover can be opened or completely closed, and the fish separating net 1410 is made of 5-mesh nylon screen gauze.

[0064] The fish outlet net 1406 is made of 5-mesh nylon screen gauze and has a height of 10 cm, the lower end of the fish outlet net 1406 is connected with the upper end of the egg collecting bag 1408, and the egg collecting bag 1408 is made of 40-mesh nylon screen gauze and has a height of 50 cm.

[0065] The bottom of the egg collecting bag 1408 is provided with a disc-shaped microporous oxygenation pipe 1409, the microporous oxygenation pipe 1409 is a coiled oxygenation pipe with a diameter of 80 cm, the microporous oxygenation pipe 1409 is connected with a gas amount adjusting valve, the gas amount adjusting valve is connected with a poolside Roots blower through a gas guide pipe to form an aeration device, the water micro-flow is controlled through the gas amount adjusting valve, and the size of the microporous oxygenation pipe 1409 is generally 20 mm in outer diameter, 10 mm in inner diameter and 2 m in length, and the diameter of the fine bubbles generated is 20-30 μm.

[0066] The float 1401 is made of foam and is a foam float with a diameter of 15 cm.

[0067] In the following, the application is further described in detail through examples.

[0068] Example

[0069] Basic conditions: the freshwater pond has an area of 10*667 m 2 , a depth of 2 m and a square shape; 2*667 m 2 overwintering workshop 1 Figs. 1-2), the cement pool 6 in the overwinter workshop is 1.5m deep, the single-side light-transmitting roof is attached with a circulating water treatment unit; the live bait feeding system 56, see Figs. 3-5 .

[0070] In this embodiment, a method for overwintering of Coilia ectenes in northern regions is provided, and the specific steps are as follows:

[0071] I. Bait fry culture

[0072] In early April, start to reserve the bait fish (megalobrama amblycephala fry) of Coilia ectenes, and reserve 10,000 kg of mature parent fish of megalobrama amblycephala for every 100,000 Coilia ectenes fry. The reserved megalobrama amblycephala fry is cultivated in a soil pond at a density of 3,000 kg / mu, and the gonadal development is controlled.

[0073] During the temporary cultivation, the flow rate is controlled, and in addition to the necessary oxygenation by an oxygenator, water supply and drainage operations are avoided, and the water quality and the bottom are stabilized by using a microecological preparation. The feed used in this stage should ensure that the crude protein content is more than 42wt%, and the crude fat content is about 10wt%, and the mineral and vitamin premix should be added before feeding the purchased finished artificial feed, so as to meet the requirements of gonadal development.

[0074] The following is the artificial feed formula for the temporary cultivation of megalobrama amblycephala mature parent fish. According to the weight percentage, the formula of the special feed for megalobrama amblycephala mature parent fish is as follows: fish meal 31%, meat powder 6%, soybean meal 15%, rapeseed meal 5%, flour 16%, aquatic feed premix 5%, fish oil 2%, soybean oil 3%, rice bran 11%, vinasse 3%, corn gluten meal 3%, and the expanded slow-sinking feed with a particle size of 1.2mm, 1.5mm or 2.0mm is prepared.

[0075] The aquatic feed premix can refer to Chinese patent publication No. CN102696923A, an aquatic premix and its application in feed additives and its compound; or, the conventional freshwater fish series compound premix produced by Tongwei Co., Ltd. is used. Or, Chinese patent publication No. CN102630821A, an aquatic breeding microbial feed premix and its preparation method; or, Chinese patent publication No. CN102783566A, a feed premix with intestinal function for aquatic animals and its preparation method.

[0076] II. Artificial insemination and hatching of Coilia ectenes

[0077] In early June, prepare for artificial insemination of wild parent fish of Coilia ectenes. Use the method of catching and processing immediately. Use the net to catch sexually mature Coilia ectenes, and select sexually mature fish. The gonadal development reaches phase IV and is transitioning to phase V. The captured male parent fish collects sperm in advance. Use a microscope to observe the maturity and activity of sperm, and prepare a cold storage environment for preservation. When the sexually mature female Coilia ectenes parent fish is captured, artificial insemination is performed immediately, and the bag is stored and brought back to the workshop for incubation.

[0078] The incubation heat accumulation of Coilia ectenes is 380 degrees Celsius. Time, Coilia ectenes fry is released into the water environment prepared in advance to help Coilia ectenes fry open its mouth. Coilia ectenes fry needs about 30-45 days from fertilized egg membrane rupture to body length reaching 3-5 cm.

[0079] III. Outdoor soil pond cultivation of Coilia ectenes fry

[0080] In early July, before the Coilia ectenes fry is released into the pond, the method of conventional bait organism culture is used to culture the soil pond living plankton bait. After the fry is released into the pond, the plankton in the soil pond is qualitatively and quantitatively determined every day to ensure that the bait supply meets the feeding needs of the Coilia ectenes fry. A living bait feeding system (Fig. 1) is set up in the soil pond for the cultivation of Coilia ectenes fry, and sexually mature wild and miscellaneous fish parent fish are continuously supplemented into the bait feeding system to ensure the normal operation of the system. Figs. 3-5

[0081] In mid-August (about 30 days after the fry is released into the soil pond), the stage of acclimating to frozen biological bait can be entered. While there are still living bait organisms in the soil pond, cut the frozen biological bait (such as frozen plate brine shrimp or frozen plate cladocera) into blocks of about 500g and throw them into the upper wind of the soil pond in the morning on sunny days. Frozen biological bait can be purchased or cultured in idle ponds and stored on filter plates. The selection of bait organisms follows the order of rotifer-cladocera-frozen biological bait-living fry-artificial compound feed.

[0082] IV. Preparation before transportation

[0083] In mid-October, the Coilia ectenes fry reaches a body length of more than 20 cm, with a uniform body shape, no disease, and no injury, and can be transferred to the preparation stage before transportation. 1. Use summer flower netting equipment to drive the fry to one side of the pond, insert straw bundles at the bottom of the net every 50 cm, with a diameter of 6 cm, and the net should not be inserted too deep into the bottom mud, about 5 cm. The netting speed should not exceed 0.5 m / s. And fix the net. 2. Set up an oxygenator on the side of the pond without Coilia ectenes fry, and discharge one-fifth of the original pond water. 3. Inject seawater with a salinity of not less than 20‰, and turn on the oxygenator for more than 12 hours. 4. Release the net and supplement probiotics to adjust the water quality. ​

[0084] 5. Preparation of wintering workshop before transportation

[0085] 1. Drain the pond, clean, and disinfect it. 2. Inject sand-filtered natural seawater, maintaining an average water level of 50 cm. 3. Open all doors and windows in the wintering room to maintain ventilation. 4. Regularly monitor the temperature difference between the outdoor earthen pond and the cement pool inside the wintering room. 5. Clean the bottom mud promptly before wintering, ensuring it is no thicker than 20 cm. 6. Start the circulating water treatment unit seven days in advance and inoculate the biofilter with probiotics.

[0086] 6. Transporting Fry

[0087] From late October to early November, when the following conditions are met: the water temperature difference between the outdoor earth pond and the cement pool 6 in the wintering workshop is less than 2°C, and seawater has been added to the outdoor earth pond for more than 5 days, the fry transportation work can begin.

[0088] Select fine day morning, carry out full pond drag net with summer flower net gear, the net gear propulsion speed is no more than 0.5m / s.Insert straw bundle in the net gear bottom, every 50cm one bundle, straw bundle diameter 6cm is advisable, and the net gear hem should not insert the sediment too deep, 5cm is advisable.Fry is driven to the pond corner with net gear, narrow down gradually, keep about 30cm depth of water in the net gear, and arrange special person to be responsible for observing the state of cutter anchovy fry in the net gear, have or not the situation of sticking net, stir current simultaneously and increase water body dissolved oxygen in the net gear.With the above container of diameter 15cm (adorn half pond water), carry seedling with water, cutter anchovy fry density is not higher than 2 tails / liter of water in the container.Fry is transported in the cement pond 6 of overwintering workshop rapidly, after needing container bottom being placed in the water, then container is overturned, fry is steadily slipped in the pond.

[0089] 7. Wintering in the workshop

[0090] like Figs. 1-2 As shown, the circulating water treatment unit in the wintering room remains operational 24 hours a day, maintaining a constant micro-flow of water. The water temperature remains above 7°C during the winter, meeting the temperature and quality requirements of the scaly anchovy. This wintering process utilizes a single-sided, light-permeable rooftop. Solar heating and nighttime insulation with straw mats maintain water temperature. This in-house circulating water treatment unit addresses the water temperature and quality challenges faced by scaly anchovy during the wintering period in northern Taiwan. Once the fry are placed in the pond, the doors and windows of the wintering room are closed, and natural seawater is added to the cement pool 6 to gradually increase the salinity of the water. This rate of addition is maintained daily, with the salinity increasing by 2‰ per day. The salinity is monitored weekly, and freshwater and seawater are added as appropriate.

[0091] 8. Start the live bait delivery system

[0092] In the pool, 56 live bait feeding systems are evenly distributed, and the live bait feeding systems are fed with Procambarus clarkii or Palaemon carinicauda, and the inflation device of the live bait feeding system is started. After hatching and cultivation, the live bait feeding system will automatically feed the newly hatched fry to the water body to feed the knife smelt fry. During this period, commercially available live fry can also be put into the pond. Before the external fry is put into the pond, it needs to be temporarily raised in the cement pool for one week, and disinfection and disease prevention and control work are done before putting it into the pond.

[0093] Nine, early spring disease prevention and control work

[0094] In February of the next year, after four months of wintering period cultivation, the knife smelt fry needs to be nutritionally enhanced and disease controlled after wintering. The probiotic group is continuously added to the circulating water of the wintering workshop to avoid water quality fluctuations due to environmental changes. The nutrition of the bait is increased, the fish that lay eggs in early spring are purchased in advance, the temperature is controlled to make them lay eggs in early February, and the hatching and cultivation are carried out to 1.5-2 cm, and they are fed to the wintering workshop in time.

[0095] The results of the examples show that the present application can effectively improve the survival rate of the knife smelt fry in the wintering link, and is a complete and efficient knife smelt fry wintering method.

Claims

1. A method for cultivating Coilia nasus fry in the overwintering period in the northern region, characterized by, The specific process is as follows: (1) bait fry culture According to 10 million tail of juvenile cobia 10,000 catty mature parent fish, the density is controlled to 3000 catty / mu during temporary culture, and the development of gonad is controlled; the artificial feed used in this stage should ensure that the crude protein content is more than 42wt%, and the crude fat content is 8~12wt%, to meet the requirements of gonad development; In step (1), the environmental conditions are controlled, the culture density is increased, the water flow rate is controlled, and the nutritional conditions of the bait fish parent fish are strengthened to promote the development of the gonad of the bait fish parent fish to stage IV and stay at stage IV; (2) outdoor soil pond culture of cobia fry Cobia fry needs 30~45 days from breaking the membrane to reaching 3~5cm in length; at this time, the cobia fry has been transferred to outdoor soil pond culture, and the soil pond live plankton feed is cultured by using the conventional bait biological culture method before the fry is put into the pond; the plankton in the soil pond is qualitatively and quantitatively determined every day after the fry is put into the pond to ensure that the bait supply meets the feeding needs of the cobia fry; a live bait feeding system dedicated to cobia fry culture is set up in the soil pond, and mature wild miscellaneous fish parent fish are continuously supplemented into the bait feeding system to ensure the normal operation of the system; After 30 days of fry in the soil pond, the cold frozen biological bait stage is entered; under the condition of live bait organisms in the soil pond, the cold frozen biological bait is cut into 500g blocks and thrown into the upper wind of the soil pond in the morning on sunny days; the selection of bait organisms is added in the order of rotifer-brine shrimp-cold frozen biological bait-live fry-artificial compound feed; after three months of culture in the soil pond, the cobia fry reaches more than 20cm in length, with uniform body shape, no disease and no injury, and is transferred to the pre-transport preparation stage; ① preparation of soil pond before transport The summer net is used for purse seining operation to drive the fry in the soil pond to one side of the pond, the net bottom is inserted with rice straw bundles every 50cm, the diameter of the rice straw bundle is 6cm, and the net bottom is inserted into the bottom mud 5cm; the purse seining advancing speed is not more than 0.5m / s, and the net is fixed; an oxygenator is erected on the side of the pond without cobia fry, and one fifth of the original pond water is discharged; sea water with salinity not less than 20‰ is injected, and the oxygenator is opened for more than 12 hours; the purse net is released, and probiotics are added to adjust the water quality; ② preparation of overwintering workshop before transport The pond water is drained, and the pond is disinfected; natural sea water filtered by sand is injected, and the average water level is controlled at 50cm; all doors and windows of the overwintering workshop are opened to maintain ventilation; the temperature difference between the outdoor soil pond and the cement pool in the overwintering workshop is monitored regularly; ③ transport of fry When the following conditions are met: the water temperature difference between the outdoor soil pond and the cement pond in the wintering workshop is less than 2℃, the outdoor soil pond is added with seawater for more than 5 days, and the fish fry transportation work starts; choose sunny morning, use summer flower net to pull the whole pond, the net advancing speed is not more than 0.5m / s; the bottom of the net is inserted with straw bundle, every 50cm a bundle, the diameter of the straw bundle is 6cm, the net lower hem is inserted into the bottom mud 5cm; the fish fry is driven to one corner of the pond with the net, the range is gradually reduced, the water depth in the net is maintained at 30cm, and the state of the knife gizzard shad fry in the net is observed, whether there is net sticking or not, at the same time, the water flow is stirred to increase the water body dissolved oxygen in the net; a half pond water is put into a container with a diameter of more than 15cm to transport the fry, the density of the knife gizzard shad fry in the container is not more than 2 tails per liter of water; the fry is quickly transported to the cement pond in the wintering workshop, the container bottom is placed in the water, then the container is poured, and the fry is smoothly slid into the pond; (3) Wintering in the wintering workshop The area of the wintering workshop is two mu, the top is single-sided light-transmitting style, the highest point is located above the cement pond, 4 / 5 of the horizontal position; a straw curtain is erected at the highest point of the roof, equipped with a roller shutter reducer to lower the straw curtain before night to keep warm; the wintering workshop uses cement pond, the pond wall is made of slope protection to prevent soil sliding, the pond bottom mud is cleaned in time before winter, the thickness is not more than 20cm; the circulating water treatment unit is kept open for 24h during the wintering period, the pond water is always in a state of micro-flow, the water temperature in winter is maintained above 7℃, which can meet the water temperature and quality requirements of knife gizzard shad during the wintering period; After the fry is put into the pond, the doors and windows of the wintering workshop are closed, the circulating water treatment unit is started 7 days in advance, and probiotics are inoculated into the biological filter tank; natural seawater is added into the cement pond, the pond water salinity is gradually increased, the adding speed is 2‰ / day to improve the pond water salinity; add for one day, keep for one day, until the pond water salinity reaches 8‰; the water salinity is detected every week, and fresh water and seawater are added according to the actual situation; In step (3), the structure of the wintering workshop is divided into three parts of cement pond, heat preservation wall and roof, the cement pond is provided with five filling layers, the filling layers are arranged from bottom to top and from outside to inside of the pond wall as follows: large stone layer, gravel layer, sandy soil layer, polystyrene board and concrete layer; a corner of the cement pond is provided with a circulating water treatment unit, the circulating water treatment unit comprises a primary filtration biological reaction filter tank, a secondary biological reaction filter tank, an ultraviolet reaction tank and an aeration heating tank which are communicated in sequence; the embankment around the top of the cement pond is built with a heat preservation wall, and the top of the heat preservation wall is provided with a roof; (4) Start the live bait feeding system The live bait feeding system is evenly arranged in the pond, the distance between two live bait feeding systems is 5-10m, the Procambarus clarkii or the Palaemon carinicauda is put into the live bait feeding system, and the inflation device of the live bait feeding system is started; after hatching and culture, the live bait feeding system will automatically put the newly hatched fry into the water body to provide food for the knife gizzard shad fry. In step (4), the upper frame body, the acrylic support plate and the lower frame body of the live bait feeding system are coaxially arranged from top to bottom and connected, the upper frame body is a cylindrical stainless steel frame, the box surrounded by the 40-mesh nylon screen gauze is covered outside the upper frame body, the upper part of the box is a lid, the bottom of the box is a fish separating net, and the top of the side of the box is tied with a float; the middle part is a ring-shaped disc-shaped acrylic support plate, which is located below the fish separating net; the lower frame body is a cylindrical stainless steel frame, the fish outlet net surrounded by the 5-mesh nylon screen gauze is covered outside the upper part of the lower frame body, and the egg collecting bag surrounded by the 40-mesh nylon screen gauze is covered outside and at the bottom of the lower frame body, and the disc-shaped microporous oxygenation pipe is hung at the bottom of the egg collecting bag. The live bait feeding system is arranged in the breeding water body and stands in the water layer in a suspended manner, and the bottom air charging device is started to operate the live bait feeding system; mature wild and miscellaneous fish parent fish are supplemented into the live bait feeding system in the outdoor soil pond cultivation link, and the egg-carrying Chinese tiger prawn or Chinese small long-clawed prawn is supplemented into the live bait feeding system during the wintering period, and the live bait fish or prawn larvae are supplemented and fed at regular time, that is, the live bait fish or prawn larvae are continuously supplemented and fed into the water body to meet the nutritional requirements of the different stages of the knife sardine fry.

2. The method for culturing Coilia nasus fry in the northern region during the overwintering period according to claim 1, characterized in that, In step (1), the water flow speed is controlled, and water supply and drainage operations are avoided except for necessary oxygenation by the oxygenation machine, and the water quality is stabilized by using the micro-ecological preparation method.

3. The method for culturing Coilia nasus fry in the northern region during the overwintering period according to claim 1, characterized in that, In step (1), the artificial compound feed formula for the temporary breeding of the mature parent fish of the Megalobrama amblycephala is as follows: according to the weight percentage, the special feed formula for the mature parent fish of the Megalobrama amblycephala is as follows: fish meal 31%, meat powder 6%, soybean meal 15%, rapeseed meal 5%, flour 16%, aquatic feed premix 5%, fish oil 2%, soybean oil 3%, rice bran 11%, vinasse 3%, and corn gluten meal 3%, and the expanded slow-sinking feed with a particle size of 1.2 mm, 1.5 mm or 2.0 mm is prepared.

4. The method for culturing Coilia nasus fry in the northern region during the overwintering period according to claim 1, characterized in that, In step (2), the frozen biological bait is purchased as a frozen plate, or the plankton is cultured in an idle pond and is freeze-plate-prepared after being filtered.

5. The northern knife jack fry overwintering period cultivation method according to claim 1, characterized by, The pool wall and the pool bottom form an angle of 135-150°, and the concrete layer is hardened to form a cement pool.

6. The northern knife jack fry overwintering period cultivation method according to claim 1, characterized by, The bottom of the egg collecting bag is hung with a disc-shaped microporous oxygenation pipe, the microporous oxygenation pipe is a disc-shaped oxygenation pipe with a diameter of 80 cm, the microporous oxygenation pipe is connected with a gas amount adjusting valve, the gas amount adjusting valve is connected with a pool side Roots blower through a gas guide pipe to form an air charging device.

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