Method for efficiently utilizing juvenile crab pond to breed penaeus vannamei in leisure period

Abstract

The invention discloses a method for breeding penaeus vannamei by efficiently utilizing a juvenile crab pond in a leisure period. The method comprises the steps of putting nereis larvae, laying a separation net at the bottom of the pond, additionally arranging an oxygenation system at the bottom of the pond and adopting a water quality regulation and control technology, and feeding residual feed and excrement generated in the prawn breeding process by utilizing the put nereis larvae; a separation net is laid at the bottom of the pond, prawn seedlings and nereis seedlings are effectively separated, and the adverse effects that prawns prey on nereis and damage nereis nests are avoided; the oxygenation system is additionally arranged at the bottom of the pond, so that the oxygen supply requirements of the prawns and the nereis can be met, and residual feed and excrement generated by the prawns can be flushed down from the separation net and can be eaten by the nereis in time; by means of the water quality regulation and control technology, the feed feeding amount is controlled, the breeding scheme is adjusted in time according to the water quality index, the breeding effect is ensured, green and efficient breeding of prawns can be achieved, adult nereis can be additionally harvested, and the output value of the juvenile crab pond in the leisure period is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of Penaeus vannamei culture, and particularly relates to a method for efficiently utilizing a crab seedling pond during the leisure period to culture Penaeus vannamei. Background Art

[0002] Crab seedling farming companies dig mudflats into earth ponds and directly use disinfected seawater to cultivate crab seedlings. The crab seedlings not only live in natural seawater, but also have sufficient oxygen and food, and the cost of raising seedlings has been greatly reduced. Therefore, after the crab seedling ponds were cleared, farming companies have also tried to breed marine economic animals such as jellyfish, Chinese shrimp, Japanese shrimp, and whiteleg shrimp, but the results were not obvious. Taking into account the breeding costs and benefits, the method currently generally adopted by crab seedling farming companies is to roughly breed whiteleg shrimp. Only about 10kg of adult shrimp can be harvested from each acre of crab seedling pond, and the economic benefits created are less than 400 yuan / acre.

[0003] The white shrimp has the advantages of strong environmental adaptability, low nutritional requirements, and long survival time out of water. It is an excellent variety for intensive and high-yield farming. It is also the shrimp variety with the highest yield among the three major farmed shrimps in the world. In order to improve the utilization efficiency of the crab seedling pond during the leisure period, you can try to increase the number of white shrimp seedlings and feed them at the same time. However, with the increase in the density of white shrimp farming, the pollution problem of aquaculture tail water has become increasingly prominent. If a large amount of untreated aquaculture wastewater is continuously discharged into the surrounding water environment, the eutrophication of the corresponding water bodies will increase, and the frequency of red tides and disease outbreaks will increase.

[0004] Nereids are a type of marine benthic animal, commonly known as sea earthworms. They mainly live on coastal tidal flats and feed mainly on organic matter in the bottom mud. They are the dominant species for ecological restoration of coastal tidal flats. In addition, nereids are rich in nutrients, rich in amino acids and various trace elements. They are known as "universal baits" and are high-quality live baits for fish, shrimps and crabs. They can improve the survival rate and growth rate of fish, shrimps and crabs. Therefore, introducing nereids into shrimp breeding ponds can not only effectively remove the residual bait and feces in the ponds, maintain the stability of the breeding water body, realize the green and efficient breeding of shrimps, and improve the utilization efficiency of the crab seedling pond during the leisure period.

[0005] Chinese patent CN109479779A discloses a high-yield and environmentally friendly breeding method for Japanese shrimp, which comprises the following steps: draining stale water from the breeding pond, drying the pond bottom, plowing and leveling the pond to a depth of 10 to 20 cm; filtering with a 100 μm pore size filter screen, and introducing 1 to 1.2 m of seawater with a salinity of 20 to 35; spraying chlorine preparations to disinfect the pond water, so that the free chlorine in the pond water reaches 20 mg / L; after the toxicity of the chlorine preparations disappears, using commercially available fertilizer products to cultivate plankton; after the water body has obvious algae color, large-sized sandworm seedlings are released, and after the sandworm seedlings are bottom-dwelling, 10,000 to 20,000 Japanese shrimp seedlings are released per mu; feeding compound feed 1 to 2 hours after sunset every day, measuring the nitrogen, phosphorus and alkalinity of the breeding water body for 5 to 10 days, and adjusting the ratio of N, P and C so that the mass ratio of the three is 7.2:1:41 until harvesting; however, considering that during the implementation of this patent, there may be situations in which shrimps eat sandworms and destroy the habitat of sandworms, which will affect the effect of mixed breeding of shrimps and sandworms. This application has newly added the laying of an isolation net at the bottom of the pond and the installation of oxygenation equipment at the bottom of the pond, which can effectively avoid these problems, achieve harmonious symbiosis between shrimps and sandworms, and increase the shrimp farming income.

[0006] Chinese patent CN 109095617A discloses an ecosystem and purification method for purifying seawater aquaculture water by composite artificial wetlands in subtropical areas, in which tidal flat shellfish and sandworms are stocked in the water body, and the seawater pond is a plankton and bacterial microecological regulation zone, with natural biological bait as the main food, 24-hour aeration and oxygenation, and aquatic animals such as fish, shrimp and crabs are stocked in the pond, and seawater vegetables such as sea lichen and saltwort are planted on the surface to regulate the plankton and bacterial microecology; however, considering that the implementation process of this application is relatively complicated, it is not suitable for the practice of shrimp farming during the leisure period of crab seedling ponds. This application combines the actual situation of the crab seedling pond during the leisure period, simplifies the process of mixed culture of white shrimp and sandworms, and is more conducive to improving the utilization efficiency of the crab seedling pond during the leisure period.

[0007] Chinese patent CN 104255632A discloses a fully enclosed, fully light-transmitting intelligent organic shrimp ecological farming device, which can cultivate zooplankton, increase oxygen and aerate, automatically feed, and adjust ammonia, phosphorus and nitrogen at will; however, considering the actual situation of the crab seedling pond during the leisure period, this technology is not practical. Summary of the invention

[0008] In view of the shortcomings of the prior art that high-density shrimp farming causes aggravated eutrophication of corresponding water bodies, increased frequency of red tides and disease outbreaks, the present invention provides a method for efficiently utilizing crab seedling ponds to farm whiteleg shrimp during the leisure period, comprising the steps of releasing lugworm seedlings, laying isolation nets on the bottom of the pond, installing an oxygenation system and water quality control technology on the bottom of the pond, so as to reduce environmental pollution and disease problems caused by high-density shrimp farming by allowing the benthic animal lugworms to eat the residual bait and feces produced by the shrimps, and also to harvest lugworms in addition, thereby increasing the comprehensive benefits of farming.

[0009] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0010] A method for efficiently utilizing crab seedling ponds to culture whiteleg shrimp during the leisure period, comprising the following steps:

[0011] The first step is to release the sandworm fry: after cleaning the pond for crab fry, drain the stale water in the breeding pond, dry the pond bottom, plow and harrow it to a depth of 15 to 25 cm, add 10 to 20 cm of seawater, spray chlorine preparations to disinfect the pond water, and after the toxicity of the chlorine preparations disappears, start to release 500 to 1000 sandworm 5-segment larvae / m 2 ;

[0012] The second step is to lay an isolation net on the bottom of the pond: after the sandworm seedlings have settled on the bottom, lay an isolation net 2 to 4 cm away from the bottom of the shrimp pond, support it with parallel keels, and the distance between the parallel keels is 4 to 5 meters. The edge of the isolation net is close to the bottom mud and compacted with bricks or prefabricated cement strips;

[0013] The third step is to install oxygenation equipment at the bottom of the pool: install microporous oxygenation aeration pipes above the isolation net, and the aeration pipes should be fixed vertically on the parallel keels; the micropores of the aeration pipes are parallel to the isolation net, and the laying spacing of the microporous oxygenation pipes is 1-2m; each microporous oxygenation pipe is connected to a variable frequency Roots blower oxygenation pump through a tee and a polyethylene hose in the middle;

[0014] Step 4: Water quality control: After the release of sandworm fry, the laying of isolation nets, and the installation of the oxygenation system, add 1 to 1.5 m of seawater; use commercially available fertilizer products to cultivate plankton, and when the water body has obvious algae color, start to release 100 to 120 white shrimp fry of 1 to 2 cm in length / m 2 Feed once every 6 hours, measure nitrogen, phosphorus and alkalinity of aquaculture water every 5-10 days, adjust the ratio of N, P and C, and start the aerator every day according to the dissolved oxygen in the water to make the dissolved oxygen in the bottom water not less than 5mg / L;

[0015] Step 5: Stop aeration for 10 to 20 minutes before each feeding, then aerate and increase the power of the aeration pump for 5 to 10 minutes; use probiotic microecological preparations once a week until harvest.

[0016] Furthermore, in the first and fourth steps, the seawater is filtered through a filter screen with a pore size of 100 μm, and the seawater with a salinity of 15 to 30 is introduced.

[0017] Furthermore, in the first step, chlorine preparation is sprayed to disinfect the pool water so that the free chlorine in the pool water reaches 20 mg / L.

[0018] Furthermore, in the second step, the isolation net is made of nylon mesh with a pore size of 40-80 meshes.

[0019] Furthermore, the second step parallel keel spacing is 5m, and the requirement is to make the isolation net tight.

[0020] Furthermore, the laying interval of the microporous aeration pipes in the third step is 1 m, so that the airflows ejected from two adjacent microporous aeration pipes can be connected on the isolation net but not overlapped.

[0021] Furthermore, the commercially available fertilizer products in the fourth step are molasses and / or amino acid fertilizer liquid, with molasses at 2 jin / mu and amino acid fertilizer liquid at 3 jin / mu.

[0022] Furthermore, the fourth-step plankton is small diatoms and / or Chlorella.

[0023] Furthermore, the fourth step uses a chemical analysis method to determine the nitrogen, phosphorus and alkalinity of the aquaculture water, and adjusts the amount of bait, molasses, and amino acid fertilizer solution added to adjust the ratio of N, P, and C so that the mass ratio of the three is 7.2:1:41; the bait is a commercially available shrimp feed.

[0024] Furthermore, the probiotic microecological preparation in the fifth step is one or more of Bacillus, lactic acid bacteria, and photosynthetic bacteria, and the dosage of the probiotic microecological preparation is 0.5 catties / mu of Bacillus, 10 catties / mu of Lactobacillus, and 10 catties / mu of photosynthetic bacteria.

[0025] Principle explanation: High-density farming in shrimp ponds is prone to large-scale shrimp diseases, which often causes shrimp farmers to suffer huge losses. This is mainly related to the low feed utilization ability of shrimp. When shrimps feed, they hold food particles with their front feet and gnaw them, which will produce a lot of food debris and lose them in the water. In addition, their feces also contain a lot of organic matter. Studies have shown that only 19% of the nitrogen fed into shrimp ponds by artificial feeding is converted into nitrogen in the shrimp body, and most of the rest accumulates at the bottom of the shrimp pond in the form of leftover bait and feces, gradually turning into toxic and harmful substances and breeding pathogenic microorganisms that endanger the health of shrimp.

[0026] In order to improve the breeding environment, farmers often use large amounts of water changes to regulate water quality. Aquaculture wastewater containing a large amount of toxic and harmful substances and pathogenic microorganisms will cause the deterioration of the water environment in the sea area around the breeding ponds, further exacerbating the spread of infectious diseases of shrimp. As a result, farmers are forced to use drugs repeatedly in large quantities, which increases the drug resistance of pathogens, forming a vicious cycle and causing serious drug residue problems in shrimp. This is a common problem in the current shrimp farming industry. In order to avoid breeding risks, some shrimp farmers have to adopt a low-input and low-output extensive breeding model; some breeding companies illegally extract groundwater for large-scale water changes. Although they have achieved safe and high-yield high-density breeding, they are extremely harmful to the environment.

[0027] Nereids are known as "pond bottom cleaners" and "universal bait." In the co-culture mode of nereids and shrimps, nereids live in caves at the bottom of the pond and feed on soil containing shrimp leftovers and feces. They can effectively remove shrimp leftovers and feces, maintain a good and stable breeding environment, and thus achieve clean, safe, high-yield, and healthy breeding of shrimps. On the basis of co-culture of shrimps and nereids, the present invention adds an isolation net and an inflation device, which can maximize the ability of nereids to clean leftover bait and feces at the bottom of the pond while ensuring the harmonious coexistence of shrimps and nereids, thereby achieving green and efficient breeding of shrimps.

[0028] Compared with the prior art, the beneficial effects of the present invention include:

[0029] 1. The present invention utilizes benthic animal lugworms to eat residual bait and feces in shrimp ponds, which can effectively increase the density of shrimp farming and solve the problem of shrimp farming pollution.

[0030] 2. Use isolation nets to effectively separate shrimps and sandworms to avoid adverse effects such as shrimps preying on sandworms and destroying sandworm nests.

[0031] 3. By adding a bottom oxygenation system, we can not only ensure the oxygen needs of shrimps and sandworms, but also flush the leftover bait and feces of shrimps down the isolation net in time, so that sandworms can better deal with the leftover bait and shrimp feces in the shrimp pond.

[0032] 4. Through water quality control technology, the ecological effect of shrimp and silkworm co-culture can be better exerted, and green and efficient shrimp farming can be achieved.

[0033] 5. The present invention can not only increase the output of prawns and reduce the pollution problem of prawn farming, but also harvest additional sandworms and increase the comprehensive benefits of the crab seedling pond during the leisure period. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0035] The present invention is further described in detail below in conjunction with specific embodiments, and in conjunction with specific comparative examples to highlight the outstanding advantages of the present invention.

[0036] The manufacturer and model of commercially available shrimp feed is Tongwei 8838 whiteleg shrimp feed.

[0037] Example 1

[0038] A method for efficiently utilizing crab seedling ponds to culture whiteleg shrimp during the leisure period, the specific steps being:

[0039] The first step is to release sandworm seedlings: On May 16, 2020, after the crab seedling pond was cleaned, the stale water in the breeding pond was drained, the pond bottom was dried and plowed and leveled, with a plowing depth of 20 cm; it was filtered with a 100 μm pore filter, and 15 cm of seawater with a salinity of 15 was added; chlorine preparations were sprayed to disinfect the pool water, so that the free chlorine in the pool water reached 20 mg / L; after the toxicity of the chlorine preparations disappeared, 800 sandworm 5-segment larvae / m 2 ;

[0040] The second step is to lay an isolation net on the bottom of the pond: after the sandworm seedlings have settled on the bottom, lay a nylon net with a pore size of 80 mesh 2 cm away from the bottom of the shrimp pond. Use parallel keels to support the net. The parallel keels are spaced 5 meters apart to keep the isolation net tight. The edge of the isolation net is pressed against the bottom mud with bricks;

[0041] The third step is to install oxygenation equipment at the bottom of the pool: install microporous oxygenation aeration pipes above the isolation net. The aeration pipes should be fixed vertically on the parallel keels; the micropores of the aeration pipes are parallel to the isolation net. The laying interval of the microporous aeration pipes is 1m so that the airflows ejected from two adjacent microporous aeration pipes are connected on the isolation net but not overlapped. Each microporous aeration pipe is connected to the variable frequency Roots blower aeration pump through a tee and a polyethylene hose in the middle;

[0042] The fourth step is water quality control: after the release of sandworm fry, the laying of isolation nets, and the installation of the oxygenation system, filter with a 100μm filter and let in 1.5m of seawater with a salinity of 15-30; use commercially available fertilizer products to cultivate plankton. After the water body has obvious algae color on June 1, start to release white shrimp fry. Each shrimp pond is released with a body length of 1.5cm. 120 shrimp fry / m 2 .

[0043] Measure the nitrogen, phosphorus and alkalinity of the aquaculture water every 7 days, adjust the ratio of N, P and C to 7.2:1:41 until harvest; start the aerator appropriately according to the dissolved oxygen in the water every day to make the dissolved oxygen in the bottom water not less than 5mg / L;

[0044] Step 5: Feed once every 6 hours. Stop aeration for 10 to 20 minutes before each feeding. Then aerate and increase the power of the aeration pump for 5 to 10 minutes. Use probiotic microecological preparations once a week.

[0045] On August 27, the three ponds harvested 68.2, 62.4 and 67.8 kg of shrimp respectively. After the ponds were dried, many sandworm nests were seen on the bottom mud of the shrimp ponds, and 27.8, 21.5 and 21.4 kg of sandworms were harvested respectively.

[0046] Example 2

[0047] A method for efficiently utilizing crab seedling ponds to culture whiteleg shrimp during the leisure period, the specific steps being:

[0048] The first step is to release the sandworm seedlings: after cleaning the crab seedling pond, drain the stale water in the breeding pond, dry the pond bottom and plow it to a depth of 15 cm; filter it with a 100μm filter, and let in 10cm of seawater with a salinity of 15; spray chlorine preparations to disinfect the pond water, so that the free chlorine in the pond water reaches 20mg / L; after the toxicity of the chlorine preparations disappears, start to release 500 sandworm 5-segment larvae / m 2 ;

[0049] The second step is to lay an isolation net at the bottom of the pond: after the sandworm seedlings are benthic, lay an isolation net 2 cm away from the bottom of the shrimp pond. The isolation net is preferably made of nylon mesh with a 40-mesh aperture. The net is supported by parallel keels. The parallel keels are spaced 4-5 m apart to make the isolation net tight. The edge of the isolation net is pressed against the bottom mud with bricks or prefabricated cement strips;

[0050] The third step is to install oxygenation equipment at the bottom of the pool: install microporous oxygenation aeration pipes above the isolation net. The aeration pipes should be fixed vertically on the parallel keels; the micropores of the aeration pipes are parallel to the isolation net. The laying interval of the microporous aeration pipes is 1m so that the airflows ejected from two adjacent microporous aeration pipes are connected on the isolation net but not overlapped. Each microporous aeration pipe is connected to the variable frequency Roots blower aeration pump through a tee and a polyethylene hose in the middle;

[0051] The fourth step is water quality control: after the release of sandworm seedlings, the laying of isolation nets, and the installation of the oxygenation system, filter with a 100μm filter and let in 1m of seawater with a salinity of 15; use commercially available fertilizer products to cultivate plankton, and when the water body has obvious algae color, start to release 100 1cm long white shrimp seedlings / m 2 ; Measure the nitrogen, phosphorus and alkalinity of the aquaculture water every 5 days, adjust the ratio of N, P and C to 7.2:1:41 until harvest; start the aerator appropriately according to the dissolved oxygen in the water every day to make the dissolved oxygen in the bottom water not less than 5mg / L;

[0052] Step 5: Feed once every 6 hours. Stop aeration for 10 minutes before each feeding. Then aerate and increase the power of the aeration pump for 5 minutes. Use probiotic microecological preparations once a week.

[0053] Example 3

[0054] A method for efficiently utilizing crab seedling ponds to culture whiteleg shrimp during the leisure period, the specific steps being:

[0055] The first step is to release the sandworm seedlings: after cleaning the crab seedling pond, drain the stale water in the breeding pond, dry the pond bottom and plow it to a depth of 25 cm; filter it with a 100μm filter, and let in 20cm of seawater with a salinity of 30; spray chlorine preparations to disinfect the pond water, so that the free chlorine in the pond water reaches 20mg / L; after the toxicity of the chlorine preparations disappears, start to release 1000 sandworm 5-segment larvae / m 2 ;

[0056] The second step is to lay an isolation net at the bottom of the pond: after the sandworm seedlings are bottom-dwelling, lay an isolation net 4 cm away from the bottom of the shrimp pond. The isolation net is preferably made of nylon mesh with an aperture of 80 mesh. The net is supported by parallel keels. The parallel keels are spaced 4-5m apart to make the isolation net tight. The edge of the isolation net is close to the bottom mud and compacted with bricks or prefabricated cement strips;

[0057] The third step is to install oxygenation equipment at the bottom of the pool: install microporous oxygenation aeration pipes above the isolation net. The aeration pipes should be fixed vertically on the parallel keels; the micropores of the aeration pipes are parallel to the isolation net. The laying interval of the microporous aeration pipes is 1m so that the airflows ejected from two adjacent microporous aeration pipes are connected on the isolation net but not overlapped. Each microporous aeration pipe is connected to the variable frequency Roots blower aeration pump through a tee and a polyethylene hose in the middle;

[0058] The fourth step is water quality control: after the release of sandworm seedlings, the laying of isolation nets, and the installation of the oxygenation system, filter with a 100μm filter and let in 1.5m of seawater with a salinity of 30; use commercially available fertilizer products to cultivate plankton, and when the water body has obvious algae color, start to release 120 2cm long white shrimp seedlings / m 2 ; Measure the nitrogen, phosphorus and alkalinity of the aquaculture water every 10 days, adjust the ratio of N, P and C to 7.2:1:41 until harvest; start the aerator appropriately according to the dissolved oxygen in the water every day to make the dissolved oxygen in the bottom water not less than 5mg / L;

[0059] Step 5: Feed once every 6 hours. Stop aeration for 20 minutes before each feeding. Then aerate and increase the power of the aeration pump for 10 minutes. Use probiotic microecological preparations once a week.

[0060] Comparative Example 1

[0061] The specific steps of traditional shrimp monoculture are as follows:

[0062] The first step is to clean the pond and maintain the water. On May 16, 2020, after cleaning the crab fry pond, the stale water in the breeding pond was drained, the bottom of the pond was dried and plowed and leveled, with a plowing depth of 20 cm; filtered with a 100μm pore size filter, and 1.5m of seawater with a salinity of 15 was introduced; chlorine preparations were sprayed to disinfect the pool water, so that the free chlorine in the pool water reached 20mg / L;

[0063] The second step is to release shrimp fry. After the toxicity of chlorine preparations disappears, commercially available water fertilizer products are used to cultivate plankton. On June 1, the water body had obvious algae color, and white shrimp fry began to be released. Each shrimp pond was released with 120 shrimp fry / m with a body length of 1.5 cm. 2 .

[0064] Step 3: Water quality testing. Measure the nitrogen, phosphorus and alkalinity of the aquaculture water every 7 days, adjust the ratio of N, P and C to 7.2:1:41 until harvest; start the aerator appropriately according to the dissolved oxygen in the water every day to make the dissolved oxygen in the bottom water not less than 5mg / L;

[0065] Step 4: Feed once every 6 hours. Stop aeration for 10 to 20 minutes before each feeding. Then aerate and increase the power of the aeration pump for 5 to 10 minutes. Use probiotic microecological preparations once a week.

[0066] On August 27, the three ponds harvested 32.6, 29.5 and 27.1 kg of shrimp respectively.

[0067] Comparative Example 2

[0068] Only add sandworms without adding isolation nets and oxygenation devices. The specific steps are as follows:

[0069] The first step is to release sandworm seedlings: On May 16, 2020, after the crab seedling pond was cleaned, the stale water in the breeding pond was drained, the pond bottom was dried and plowed and leveled, with a plowing depth of 20 cm; it was filtered with a 100 μm pore filter, and 15 cm of seawater with a salinity of 15 was added; chlorine preparations were sprayed to disinfect the pool water, so that the free chlorine in the pool water reached 20 mg / L; after the toxicity of the chlorine preparations disappeared, 800 sandworm 5-segment larvae / m 2 ;

[0070] The second step is to release shrimp seedlings: one week after the release of sandworm seedlings, filter with a 100μm filter and let in 1.5m of seawater with a salinity of 15-30; use commercially available fertilizer products to cultivate plankton. On June 1, the water body has obvious algae color, and the release of white shrimp seedlings begins. Each shrimp pond is released with a body length of 1.5cm. 120 shrimp seedlings / m 2 .

[0071] The third step is water quality testing: measure the nitrogen, phosphorus and alkalinity of the aquaculture water every 7 days, adjust the ratio of N, P and C to 7.2:1:41 until harvest; start the aerator appropriately according to the dissolved oxygen in the water every day to make the dissolved oxygen in the bottom water not less than 5mg / L;

[0072] Step 4: Feed once every 6 hours. Stop aeration for 10 to 20 minutes before each feeding. Then aerate and increase the power of the aeration pump for 5 to 10 minutes. Use probiotic microecological preparations once a week.

[0073] On August 27, the three ponds harvested 48.6, 51.4 and 50.8 kg of shrimp respectively. After the ponds were dried, many sandworm nests were seen on the bottom mud of the shrimp ponds, and 12.6, 14.5 and 11.9 kg of sandworms were harvested respectively.

[0074] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for efficiently utilizing crab seedling ponds to culture whiteleg shrimp during the leisure period, characterized in that: The following steps are involved: The first step is to release the sandworm fry: after cleaning the pond for crab fry, drain the stale water in the breeding pond, dry the pond bottom, plow and harrow it to a depth of 15 to 25 cm, add 10 to 20 cm of seawater, spray chlorine preparations to disinfect the pond water, and after the toxicity of the chlorine preparations disappears, start to release 500 to 1000 sandworm 5-segment larvae / m 2 ; The second step is to lay an isolation net on the bottom of the pond: after the sandworm seedlings have settled on the bottom, lay an isolation net 2 to 4 cm away from the bottom of the shrimp pond, support it with parallel keels, and the distance between the parallel keels is 4 to 5 meters. The edge of the isolation net is close to the bottom mud and compacted with bricks or prefabricated cement strips; The third step is to install oxygenation equipment at the bottom of the pool: install microporous oxygenation aeration pipes above the isolation net, and the aeration pipes should be fixed vertically on the parallel keels; the micropores of the aeration pipes are parallel to the isolation net, and the laying spacing of the microporous oxygenation pipes is 1-2m; each microporous oxygenation pipe is connected to a variable frequency Roots blower oxygenation pump through a tee and a polyethylene hose in the middle; Step 4: Water quality control: After the release of sandworm fry, the laying of isolation nets, and the installation of the oxygenation system, add 1 to 1.5 m of seawater; use commercially available fertilizer products to cultivate plankton, and when the water body has obvious algae color, start to release 100 to 120 white shrimp fry of 1 to 2 cm in length / m 2 Feed once every 6 hours, measure nitrogen, phosphorus and alkalinity of aquaculture water every 5-10 days, adjust the ratio of N, P and C, and start the aerator every day according to the dissolved oxygen in the water to make the dissolved oxygen in the bottom water not less than 5mg / L; Step 5: Stop aeration for 10 to 20 minutes before each feeding, then aerate and increase the power of the aeration pump for 5 to 10 minutes; use probiotic microecological preparations once a week until harvest.

2. The method for efficiently utilizing the crab seedling pond during the leisure period to cultivate Penaeus vannamei according to claim 1, characterized in that: In the first and fourth steps, the seawater is filtered through a filter screen with a pore size of 100 μm, and the seawater with a salinity of 15 to 30 is introduced.

3. The method for efficiently utilizing the crab seedling pond during the leisure period to cultivate Penaeus vannamei according to claim 1, characterized in that, In the first step, chlorine preparation is sprayed to disinfect the pool water so that the free chlorine in the pool water reaches 20 mg / L.

4. The method for efficiently utilizing the crab seedling pond during the leisure period to cultivate Penaeus vannamei according to claim 1, characterized in that: In the second step, the isolation net is made of nylon mesh with a pore size of 40-80 meshes.

5. The method for efficiently utilizing the crab seedling pond during the leisure period to cultivate Penaeus vannamei according to claim 1, characterized in that: The second step is to have a parallel purlin spacing of 5m, with the requirement to keep the isolation net tight.

6. The method for efficiently utilizing crab seedling ponds to culture whiteleg shrimp during the leisure period according to claim 1, characterized in that: The laying spacing of the microporous oxygenation pipes in the third step is 1m.

7. The method for efficiently utilizing crab seedling ponds during the leisure period to culture Penaeus vannamei according to claim 1, characterized in that: The commercially available fertilizer products in the fourth step are molasses and / or amino acid fertilizer liquid, with 2 jin / mu for molasses and 3 jin / mu for amino acid fertilizer liquid.

8. The method for efficiently utilizing crab seedling ponds to culture Penaeus vannamei during the leisure period according to claim 1, characterized in that: The fourth step plankton is small diatoms and / or Chlorella.

9. The method for efficiently utilizing crab seedling ponds to culture Penaeus vannamei during the leisure period according to claim 1, characterized in that: The fourth step uses chemical analysis to determine the nitrogen, phosphorus and alkalinity of the aquaculture water, and adjusts the ratio of N, P and C by adjusting the amount of bait, molasses and amino acid fertilizer solution added, so that the mass ratio of the three is 7.2:1:41; the bait is commercially available shrimp feed.

10. The method for efficiently utilizing crab seedling ponds during the leisure period to culture Penaeus vannamei according to claim 1, characterized in that: The probiotic microecological preparation in the fifth step is one or more of Bacillus, lactic acid bacteria, and photosynthetic bacteria. The dosage of the probiotic microecological preparation is 0.5 catties / mu of Bacillus, 10 catties / mu of Lactobacillus, and 10 catties / mu of photosynthetic bacteria.