A method for overwintering and engineering of large-mouth bass fry in a recirculating water culture

Abstract

The application discloses a large-mouth bass fry overwintering domestication and engineering circulating water breeding method and relates to the technical field of aquaculture. The breeding method comprises the following steps: overwintering domestication of fish fry, construction of an ecological breeding system and breeding of the domesticated fish fry by using the system; the overwintering domestication of the fish fry is to domesticate the fish fry with a body length of 0.9-1.2 mm to large-size fish fry with a body length of 6-8 cm so that the fish fry can adapt to artificial compound feed; the domestication time is from November to December of each year to March of the next year; and the domestication is divided into first-stage domestication and second-stage domestication. The overwintering domestication of the fish fry is achieved by strictly adjusting the feeding mode and reducing the stress damage, the problem of low survival rate caused by too early domestication can be solved, the fish fry can smoothly overwinter, large-size fish fry that is well domesticated can be obtained in advance, the well-domesticated fish fry is bred in the breeding system, the intensive, intelligent, green and ecological breeding effect can be achieved, the fish fry can be put on the market in advance and a higher market price can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aquaculture, in particular to a method for overwintering and domesticating Micropterus salmoides fry and engineering recirculating aquaculture. BACKGROUND

[0002] Micropterus salmoides, commonly known as California bass in China, belongs to the family Centrarchidae of the order Perciformes, and is originally from North America. It is delicious and nutritious, has no intermuscular spine, and is suitable for all ages. It is a good water product for current aquaculture development. In aquaculture, the bait mainly depends on fresh fish, and low-value marine fish or freshwater wild fish is mainly fed. The bait coefficient is 7.5-8.0, and only the small fish consumed by domestic Micropterus salmoides aquaculture reaches hundreds of thousands of tons per year, which is high in cost and not conducive to large-scale aquaculture. Therefore, domestication is needed.

[0003] Traditional domestication is carried out when the body length of Micropterus salmoides is 1-3 cm. Early domestication can save costs, but the earlier the use of feed for domestication, the more likely it is to cause oxidative stress in the liver of fry. In addition, the changes in the external environment such as light and sound during the cultivation process stimulate the fry liver to be prone to stress damage and lesions, which can cause a series of problems such as enteritis, indigestion, and stress, leading to reduced disease resistance, and thus low success rate of domestication, high mortality and high deformity rate. The current research on Micropterus salmoides fry domestication mainly focuses on the transition feeding skills and procedures, but the success rate of transition feeding has been at a low level.

[0004] At the same time, Micropterus salmoides generally hatches in March and starts domestication. After domestication, it needs to be raised to October-November to be sold. At this time, a large number of adult fish are concentrated on the market, leading to oversupply and low prices. Therefore, it is necessary to overwinter the fry, i.e. to start domestication in November-December each year, and to obtain domesticated fry in March of the following year. The fish can be sold in advance in August to obtain a higher market price. The current overwintering is greatly affected by the environment, the domestication standard is not clear, and it is not easy to succeed.

[0005] In addition, the scale of aquaculture produces a large amount of sewage, and the existing aquaculture methods and aquaculture systems have not achieved ideal sewage treatment effects, and cannot achieve intensive and ecological aquaculture effects.

[0006] Based on the above problems, the present application aims to provide a method for overwintering and domesticating Micropterus salmoides fry and engineering recirculating aquaculture. SUMMARY

[0007] To address the above shortcomings, this invention provides a method for the overwintering domestication and engineered recirculating aquaculture of largemouth bass fry. This method employs techniques such as strictly adjusting feeding methods and reducing stress damage to domesticate fry with a body length of 0.9–1.2 mm during winter. This solves the problems of high disease rates and low survival rates caused by premature domestication, and also ensures successful overwintering. Ultimately, this results in larger, domesticated fry being obtained earlier. Intensive farming of these larger fry in the aquaculture system achieves intensive, intelligent, green, and ecological aquaculture effects, and allows for earlier market entry and higher market prices. The specific technical solution is as follows:

[0008] An engineered circular aquaculture method for largemouth bass includes overwintering and domesticating fish fry, constructing an ecological aquaculture system, and using the ecological aquaculture system to raise domesticated large-sized fish fry.

[0009] The overwintering acclimatization process begins with fry measuring 0.9–1.2 mm in body length and progresses to larger fry measuring 6–8 cm in body length, adapting them to formulated feed. The acclimatization period lasts from November / December to March of the following year. The acclimatization process is divided into two stages: a first stage and a second stage.

[0010] The first stage of acclimatization involves placing largemouth bass fry with a body length of 0.9–1.2 mm into a rearing pond equipped with a shade structure, aeration holes, and lights. Acclimatization is carried out in a dark environment. Each time they are fed, the lights are turned on and the water surface is tapped to create vibration. The specific feeding method is as follows:

[0011] Feed live brine shrimp 5 to 7 times a day for days 1-3.

[0012] From day 4 to day 6, feed 5 to 7 times a day with live brine shrimp and copepods as live food, with a ratio of 7:3 between the two.

[0013] From day 7 to day 9, feed 5 to 7 times a day with live copepods, rotifers and powdered feed in a ratio of 7:1:2.

[0014] On days 10-12, feed 4-5 times a day with live copepods, rotifers and powdered feed in a ratio of 3:3:4.

[0015] From day 13 to day 15, feed 4 to 5 times a day, feeding rotifers, powdered feed and small pellet feed in a ratio of 3:5:2.

[0016] From day 16 to 18, feed 4 to 5 times a day, using rotifers, powdered feed and small pellet feed in a ratio of 1:4:5.

[0017] From day 19 to 21, feed 4 to 5 times a day, using powdered feed and small pellet feed in a ratio of 2:8.

[0018] From day 22 to 24, feed 4 to 5 times a day, using small and medium-sized pellet feed in a ratio of 8:2.

[0019] From day 25 to 27, feed 4 to 5 times a day, using small and medium-sized pellets in a ratio of 4:6.

[0020] From day 28 to 30, feed 4 to 5 times a day, using small and medium-sized pellets in a ratio of 2:8.

[0021] The second stage of domestication involves transferring the fish fry obtained from the first stage of domestication to a workshop for continued temperature-controlled cultivation at 16-19°C. The fish are fed 4-5 times a day with a mixture of medium and large pellet feed. On the first day, the ratio of the two feeds is 8:2. Afterward, the proportion of large pellet feed in the mixture increases by 5%-10% each day until it is entirely large pellet feed. Then, the feeding is changed to 3 times a day, and the fish are raised until they reach a body length of 6-8 cm, thus obtaining the large-sized fish fry.

[0022] When feeding the above-mentioned feeds, an immune enhancer must be added to the corresponding feed. The immune enhancer consists of the following raw materials in parts by weight: 20-30 parts yeast glucan and 0.1-0.8 parts glycyrrhizic acid. The amount of the immune enhancer added is 0.01-0.04% of the total weight of the feed.

[0023] Preferably, the powdered feed is made by grinding feed into powder; the small pellet feed has a particle size of 0.5-0.9 mm, the medium pellet feed has a particle size of 1-1.9 mm, and the large pellet feed has a particle size of 2-3 mm.

[0024] Preferably, during the first stage of domestication, the total amount of feed given each time accounts for 2% to 5% of the total weight of the fish fry being fed, and the feeds are mixed evenly before feeding.

[0025] Preferably, the total amount of feed given during each stage of the second-stage acclimatization is 3% to 5% of the total weight of the fish fry being fed.

[0026] Preferably, the first and second stages of domestication also include screening every 5-8 days, placing fish fry of uniform body length into the same pond for cultivation; spraying photosynthetic bacteria and EM bacteria into the pond every 7-8 days, and regularly disinfecting the pond.

[0027] Preferably, the ecological aquaculture system includes a pond and a wastewater treatment area; the pond is equipped with a water flow channel, an aquatic plant planting area, a power aerator, and a retaining wall; the water flow channel is a long, narrow channel with open ends, located near and parallel to the edge of the pond, with a wastewater collection area at the rear end; the water flow channel is divided into multiple aquaculture areas, each with an air-lifting and water-propulsing device at its front end, and each aquaculture area has an aerator inside; the aquatic plant planting area is located within the pond; the power aerator is located at the four corners of the pond and is aligned with the water flow direction of the water flow channel; the retaining wall is constructed of bricks, iron frames, or mesh, located at the rear end of the water flow channel and perpendicular to it; the aquaculture system also includes an equipment fault alarm system, a disease detection system, and an online water quality monitoring system; the equipment fault alarm system is connected to the air-lifting and water-propulsing device and the aerator; the online water quality monitoring system is connected to the water flow channel.

[0028] Preferably, the wastewater treatment area includes: a first sedimentation tank, a first filter dam, a second sedimentation tank, an aeration tank, a second filter dam, a microbial treatment tank, and an aquatic plant purification tank; the first sedimentation tank is connected to the wastewater collection area via a sludge suction device; the first sedimentation tank is connected to the second sedimentation tank via the first filter dam, the outlet of the second sedimentation tank is connected to the inlet of the aeration tank, the aeration tank is connected to the microbial treatment tank via the second filter dam, the bottom of the aeration tank is equipped with an aeration device, the outlet of the microbial treatment tank is connected to the inlet of the aquatic plant purification tank; the bottom of the microbial treatment tank is equipped with a heating pipe, the outside of the heating pipe is equipped with a protective pipe, and the heating pipe is connected to a heating device.

[0029] Preferably, the first filtration dam is provided with, in sequence from the first sedimentation tank to the second sedimentation tank, a filter screen layer, an organic matter degradation layer, and an ammonia nitrogen adsorption layer; the second filtration dam is provided with, in sequence from the aeration tank to the microbial treatment tank, a filter screen layer, an organic matter degradation layer, and an ammonia nitrogen adsorption layer; the organic matter degradation layer is composed of biological packing material, and the surface of the biological packing material is coated with a microbial membrane capable of degrading organic matter; the ammonia nitrogen adsorption layer is filled with zeolite sheets.

[0030] Preferably, the steps for raising the overwintered, domesticated large-sized fish fry using the ecological aquaculture system are as follows:

[0031] (1) Preparation before breeding: Check the operation of the air lift water pusher, aeration equipment, sludge suction device, power aeration device and water quality online monitoring system in the breeding system to ensure that they can operate normally;

[0032] (2) Disinfection: 15 to 20 days before the fish fry are released into the tank, the pond and the water tank are disinfected with quicklime and tea seed cake; the amount of quicklime is 75 to 100 kg / mu and the amount of tea seed cake is 40 to 50 kg / mu, and it is sprinkled throughout the pond when used;

[0033] (3) Stocking fish fry: Select healthy, large-sized fish fry that have been domesticated and put them into a flowing water tank for intensive farming. On the first day, the water flow rate in the flowing water tank is controlled at 4 to 6 m / min. After that, the flow rate is adjusted once every half month, increasing by 0.7 to 1.2 m / min each time.

[0034] (4) Feeding management: Feed large-particle feed three times a day at 7-8 am, 12-13 pm and 5-18 pm respectively. The total amount of feed per day is 2% to 5% of the total weight of the fish in the flow channel. Feeding is carried out at the air push end of the flow channel.

[0035] (5) Sewage suction: Sewage suction is performed 1.5 to 2 hours after feeding. The feces and uneaten feed in the sewage collection area are sucked into the sewage treatment area for sewage treatment through the sewage suction device.

[0036] (6) Supporting species for aquaculture: Filter-feeding fish, snails and shellfish are stocked outside the water tank, including 50-100 silver carp / mu, 50-80 bighead carp / mu, 200-400 crucian carp / mu, 30-50 kg snails / mu, and 20-40 kg freshwater shellfish / mu.

[0037] (7) Aquatic plant planting area: Construct 75-150㎡ of biological floating beds per mu, and plant rice, water spinach, whorled hydrangea and / or canna in the biological floating beds. The biological floating beds are fixed with ropes and wooden stakes.

[0038] (8) Daily management: Observe the fish’s activity and feeding every day, and pay attention to the status of the online water quality monitoring system and the equipment fault alarm system; promptly and harmlessly dispose of abnormal, injured, sick and dead fish; use the disease detection system to detect suspected diseased fish, treat the symptoms, and keep aquaculture records.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] 1. This invention uses techniques such as strictly adjusting feeding methods and reducing stress damage to acclimate fish fry with a body length of 0.9-1.2mm to overwinter. This solves the problem of high breeding costs caused by late acclimatization (currently, acclimatization begins when the average body length of the fry is over 0.8cm). Acclimatization can be carried out earlier, reducing breeding costs. It also solves the problem of high disease rate and low survival rate of fry caused by acclimatization too early, and enables the fry to overwinter successfully. Ultimately, large-sized acclimatized fry can be obtained earlier. Intensive breeding of large-sized acclimatized fry in this breeding system can achieve intensive, intelligent, green, and ecological breeding effects, and can also be brought to market earlier to obtain higher market prices.

[0041] 2. The first-stage acclimatization method of this invention can reduce stress, improve resistance, and reduce disease, achieving a survival rate of over 50% in the first stage. Specifically, each feeding involves turning on the lights and tapping the water surface to create vibration, establishing a conditioned reflex in the fish fry that they gather in response to light and vibration. This ensures that all fry can eat the feed, resulting in uniform growth and reducing cannibalism. Simultaneously, an immune enhancer is added to the feed each time. The yeast glucan and glycyrrhizic acid in the immune enhancer work together to effectively alleviate oxidative stress on the fry's liver caused by changes in feed and environment, preventing liver stress damage and lesions that reduce disease resistance, thereby reducing morbidity and increasing the survival rate of acclimatized fish. Furthermore, oxalic acid also has a feeding attraction effect, encouraging the fry to feed. The second-stage acclimatization method of this invention allows the fish fry to gradually adapt to the external water temperature (i.e., the water temperature at the beginning of spring).

[0042] 3. This invention overcomes the problem of overwintering fish fry. The overwintering process begins in November or December each year, and the domesticated fish fry can be obtained in March of the following year. This is superior to the traditional method (which typically begins around March each year). Moreover, the survival rate of overwintering is high, reaching over 50%. The domesticated fish fry are sized to less than 100 fish per pound. Fish fry domesticated using this invention can be marketed around August each year, about 3 months earlier than traditional farming methods, thus meeting market demand.

[0043] 4. The aquaculture system of this invention can handle a large amount of pollutants. Through the combined action of five pools and two dams, namely the first sedimentation pool, the first filter dam, the second sedimentation pool, the aeration pool, the second filter dam, the microbial treatment pool, and the aquatic plant purification pool, the pollutants can be fully settled, filtered, degraded, and absorbed, resulting in good pollution removal effect, meeting the discharge standards, and solving the wastewater treatment problem generated by large-scale aquaculture. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0045] Figure 1 This is a schematic diagram of the aquaculture system structure of the present invention;

[0046] Figure 2 This is a schematic diagram of the wastewater treatment area structure of the present invention;

[0047] Figure 3 This is a schematic diagram of the wastewater treatment area of ​​the present invention.

[0048] Explanation of main figure symbols

[0049] 1-Pond, 2-Sewage treatment area, 3-Flowing water channel, 4-Aquatic plant planting area, 5-Powered aeration device, 6-Sewage collection area, 7-Airlift water-pushing device, 8-Aeration equipment, 9-Sewage suction device, 10-Disease detection system, 11-Water quality online monitoring system, 12-Equipment fault alarm system, 13-Water retaining wall, 14-First sedimentation tank, 15-First filter dam, 16-Second sedimentation tank, 17-Aeration tank, 18-Second filter dam, 19-Microbial treatment tank, 20-Aquatic plant purification tank, 21-Filter screen layer, 22-Organic matter degradation layer, 23-Ammonia nitrogen adsorption layer, 24-Aeration device, 25-Protective pipe and 26-Heating pipe. Detailed Implementation

[0050] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0051] Example 1

[0052] The steps for an engineered, recirculating aquaculture system for largemouth bass are as follows:

[0053] (1) Overwintering domestication of fish fry: including the first stage of domestication and the second stage of domestication;

[0054] The first stage of acclimatization involved placing largemouth bass fry with an average body length of 0.9 mm into a rearing pond equipped with a shade structure, aeration holes, and lights in November 2020. Acclimatization was conducted in a dark environment, with the lights turned on and the water surface vibrated during each feeding. The specific feeding method was as follows: Days 1-3: Feed 6 times a day with live brine shrimp; Days 4-6: Feed 6 times a day with live brine shrimp and copepods in a 7:3 ratio; Days 7-9: Feed 6 times a day with live copepods, rotifers, and powdered feed in a 7:1:2 ratio; Days 10-12: Feed 5 times a day with live copepods, rotifers, and powdered feed in a 3:3:4 ratio; Days 13-15: Feed 5 times a day with... Rotifers, powdered feed, and small pellet feed were fed in a ratio of 3:5:2. From day 16 to 18, the feed was given 5 times a day, with a ratio of 1:4:5. From day 19 to 21, the feed was given 4 times a day, with a ratio of 2:8 between powdered feed and small pellet feed. From day 22 to 24, the feed was given 4 times a day, with a ratio of 8:2 between small and medium pellet feed. From day 25 to 27, the feed was given 4 times a day, with a ratio of 4:6 between small and medium pellet feed. From day 28 to 30, the feed was given 4 times a day, with a ratio of 2:8 between small and medium pellet feed. Each feeding amount was 2% of the total weight of the fry. All feeds were mixed thoroughly before feeding. Among them, powdered feed is feed ground into powder, with small pellets having a particle size of 0.5mm, medium pellets having a particle size of 1mm, and large pellets having a particle size of 2mm. At this time, the average body length of the domesticated fish fry exceeds 3.0cm.

[0055] The second stage of domestication involves transferring the fish fry obtained in the first stage to a workshop for continued temperature-controlled cultivation at 16℃. They are fed four times a day with a mixture of medium and large pellet feed. On the first day, the ratio of medium to large pellet feed is 8:2. Afterward, the proportion of large pellet feed in the mixture increases by 5% daily until it consists entirely of large pellet feed, at which point feeding is reduced to three times a day. Each feeding session accounts for 3% of the total weight of the fish fry. Once the average body length reaches 6cm, the fish fry are considered large-sized.

[0056] When feeding the above-mentioned feeds, an immune enhancer must be added to the corresponding feed. The immune enhancer consists of the following raw materials in parts by weight: 20 parts yeast glucan and 0.1 parts glycyrrhizic acid; the amount of the immune enhancer added is 0.01% of the total weight of the feed.

[0057] Routine Management: The first and second stages of acclimatization also include screening every 5 days, placing fry of roughly the same body length into the same pond for cultivation; spraying photosynthetic bacteria and EM bacteria into the pond every 7 days, and regularly disinfecting the pond. During the acclimatization period, dissolved oxygen is controlled at 4 mg / L, ammonia nitrogen is less than 0.05 mg / L, nitrite is less than 0.1 mg / L, and pH is 7.0.

[0058] (2) Construction of ecological aquaculture system

[0059] Ecological aquaculture system (see) Figure 1 The system includes a pond 1 and a wastewater treatment area 2. The pond 1 is equipped with a water channel 3, an aquatic plant planting area 4, a water retaining wall 13, and a power aeration device 5. The water channel 3 is a long, narrow channel with open ends. The water channel 3 is located near the edge of the pond 1 and is parallel to the edge of the pond 1. The rear end of the water channel 3 is equipped with a wastewater collection area 6. The water channel 3 is divided into multiple aquaculture areas. Each aquaculture area is equipped with an air-lifting and water-pushing device 7 at its front end and an aeration device 8 inside each aquaculture area. The aquatic plant planting area 4 is located inside the pond 1. The power aeration device 5 is located at the four corners of the pond 1 and is aligned with the water flow direction of the water channel 3. The water retaining wall 13 is constructed of bricks, iron frames, or netting and is located at the rear end of the water channel 3 and is perpendicular to the water channel 3. The aquaculture system is also equipped with an equipment fault alarm system 12, a disease detection system 10, and a water quality online monitoring system 11. The equipment fault alarm system 12 is connected to the air lift and water push device 7 and the oxygenation equipment 8, and the water quality online monitoring system 11 is connected to the water flow channel 3.

[0060] Wastewater treatment area 2 (e.g.) Figure 2 and Figure 3(As shown) includes: a first sedimentation tank 14, a first filter dam 15, a second sedimentation tank 16, an aeration tank 17, a second filter dam 18, a microbial treatment tank 19, and an aquatic plant purification tank 20; the first sedimentation tank 14 is connected to the sewage collection area 6 via a sludge suction device 9, which pumps the sewage from the sewage collection area 6 to the first sedimentation tank 14 for preliminary sedimentation, removing large particulate suspended solids; the first sedimentation tank 14 is connected to the second sedimentation tank 16 via the first filter dam 15, which intercepts large particulate pollutants, degrades some organic pollutants, and adsorbs and removes some ammonia nitrogen from the pollutants, reducing ammonia nitrogen and lowering the pH of the sewage; the outlet of the second sedimentation tank 16 is connected to the inlet of the aeration tank 17, and the second sedimentation tank 16 removes small and medium-sized particles that have passed through the first filter dam 15. After particulate matter is removed by sedimentation, it flows into aeration tank 17 through the outlet. Aeration tank 17 is connected to microbial treatment tank 19 through a second filter dam 16. The second filter dam 18 intercepts small and medium-sized particulate pollutants, degrades some organic pollutants, and adsorbs and removes some ammonia nitrogen from the pollutants. The reduction of ammonia nitrogen further lowers the pH of the wastewater. Aeration device 24 is installed at the bottom of aeration tank 17 to oxygenate the wastewater before it flows into microbial treatment tank 19. Microorganisms in microbial treatment tank 19 react with pollutants, removing pollutants such as nitrogen and phosphorus. The outlet of microbial treatment tank 19 is connected to the inlet of aquatic plant purification tank 20. The water treated by microorganisms flows into aquatic plant purification tank 20 for final purification treatment. Aquatic plant purification tank 20 can further absorb and remove pollutants such as nitrogen and phosphorus. Through the combined action of the five tanks and two dams—first sedimentation tank 14, first filter dam 15, second sedimentation tank 16, aeration tank 17, second filter dam 18, microbial treatment tank 19, and aquatic plant purification tank 20—pollutants can be fully sedimented, filtered, degraded, and absorbed, resulting in good pollution removal effect and meeting discharge standards.

[0061] The first filter dam 15 is provided with the following in sequence from the first sedimentation tank 14 to the second sedimentation tank 16: a filter screen layer 21, an organic matter degradation layer 22, and an ammonia nitrogen adsorption layer 23; the second filter dam 18 is provided with the following in sequence from the aeration tank 17 to the microbial treatment tank 19: a filter screen layer 21, an organic matter degradation layer 22, and an ammonia nitrogen adsorption layer 23; the mesh size of the filter screen layer 21 on the first filter dam 15 is larger than that on the filter screen layer 21 on the second filter dam 18.

[0062] The bottom of the microbial treatment tank 19 is equipped with a heating pipe 26, which provides a suitable reaction temperature for the microorganisms. A protective pipe 25 is installed outside the heating pipe to protect it from corrosion. The heating pipe 26 is connected to a heating device, which can be a boiler. After the wastewater flows into the microbial treatment tank 19, the temperature is first raised to the optimal temperature for microbial growth (the temperature is adjusted according to the type of microorganism to be used), and then the appropriate microbial agent is added to initiate the reaction.

[0063] (3) An ecological aquaculture system is used to raise large-sized fish fry after domestication. The method is as follows:

[0064] S1. Preparations before aquaculture: Check the operation of the airlift and water propulsion device, aeration equipment, sludge suction device, power aeration device, and online water quality monitoring system in the aquaculture system to ensure that they are operating normally.

[0065] S2. Disinfection: 15 days before the fish fry are released into the tank, disinfect the pond and the water tank with quicklime and tea seed cake; the amount of quicklime is 75 kg / mu and the amount of tea seed cake is 40 kg / mu. Soak the tea seed cake for 18 hours before use and then sprinkle it throughout the pond.

[0066] S3. Stocking fish fry: Select healthy, large-sized fish fry that have been domesticated and put them into a flowing water tank for intensive farming. On the first day, the water flow rate in the flowing water tank should be controlled at 4 m / min. After that, adjust the flow rate once every half month, increasing it by 0.7 m / min each time.

[0067] S4. Feeding Management: Feed large-particle feed three times a day at 7:00, 12:00 and 17:00. The total daily feed amount is 2% of the total weight of the fish in the flow tank. Feeding is carried out at the air push end of the flow tank.

[0068] S5. Sludge suction: Sludge suction is performed within 1.5 hours after feeding. The feces and uneaten feed in the sludge collection area are sucked into the sewage treatment area for sewage treatment.

[0069] S6. Supporting Aquaculture Species: Filter-feeding fish, snails, and shellfish are stocked outside the flow channel, including silver carp (250g / kg).

[0070] 50 fish / mu for silver carp (250g / fish), 50 fish / mu for bighead carp (250g / fish), 200 fish / mu for crucian carp (50g / fish), 30kg / mu for river snails, and 20kg / mu for freshwater shellfish.

[0071] S7. Aquatic plant planting area: Construct 750㎡ of bio-floating beds per acre, and plant rice, water spinach and whorled hydrilla in the bio-floating beds. The bio-floating beds are fixed with ropes and wooden stakes and can be moved to places that need purification.

[0072] S8. Daily Management: Observe the fish's activity and feeding behavior daily, and pay attention to the status of the online water quality monitoring system and equipment malfunction alarm system; promptly and harmlessly dispose of abnormal, injured, sick, and dead fish; use the disease detection system to test suspected diseased fish, administer appropriate medication, and keep good aquaculture records.

[0073] The aquaculture system of this invention was used for breeding, and the product was launched in August 2021, about three months earlier than the traditional breeding method, thus meeting market demand.

[0074] Example 2

[0075] The steps for an engineered, recirculating aquaculture system for largemouth bass are as follows:

[0076] (1) Overwintering domestication of fish fry: including the first stage of domestication and the second stage of domestication;

[0077] The first stage of acclimatization involved placing largemouth bass fry with an average body length of 1.2 mm into a rearing pond equipped with a shade structure, aeration holes, and lights in December 2020. Acclimatization was conducted in a dark environment, with the lights turned on and the water surface vibrated during each feeding. The specific feeding method was as follows: Days 1-3: Feed 6 times a day with live brine shrimp; Days 4-6: Feed 6 times a day with live brine shrimp and copepods in a 7:3 ratio; Days 7-9: Feed 6 times a day with live copepods, rotifers, and powdered feed in a 7:1:2 ratio; Days 10-12: Feed 5 times a day with live copepods, rotifers, and powdered feed in a 3:3:4 ratio; Days 13-15: Feed 5 times a day with... Rotifers, powdered feed, and small pellet feed were fed in a ratio of 3:5:2. From day 16 to 18, the feed was given 5 times a day, with a ratio of 1:4:5. From day 19 to 21, the feed was given 4 times a day, with a ratio of 2:8 between powdered feed and small pellet feed. From day 22 to 24, the feed was given 4 times a day, with a ratio of 8:2 between small and medium pellet feed. From day 25 to 27, the feed was given 4 times a day, with a ratio of 4:6 between small and medium pellet feed. From day 28 to 30, the feed was given 4 times a day, with a ratio of 2:8 between small and medium pellet feed. Each feeding amount should be 5% of the total weight of the fry. All feeds should be mixed thoroughly before feeding. Among them, powdered feed is feed ground into powder, with small pellets having a particle size of 0.9mm, medium pellets having a particle size of 1.9mm, and large pellets having a particle size of 3mm. At this time, the average body length of the fish fry exceeds 3.0cm.

[0078] The second stage of domestication involves transferring the fish fry obtained in the first stage to a workshop for continued temperature-controlled cultivation at 19°C. They are fed four times a day with a mixture of medium and large pellet feed. On the first day, the ratio of medium to large pellet feed is 8:2. Afterward, the proportion of large pellet feed in the mixture increases by 10% daily until it consists entirely of large pellet feed. Then, feeding is reduced to three times a day. Each feeding session accounts for 5% of the total weight of the fish fry. Once the average body length reaches 8cm, the fish fry are considered large-sized.

[0079] When feeding the above-mentioned feeds, an immune enhancer must be added to the corresponding feed. The immune enhancer consists of the following raw materials in parts by weight: 30 parts yeast glucan and 0.8 parts glycyrrhizic acid; the amount of the immune enhancer added is 0.04% of the total weight of the feed.

[0080] Routine Management: The first and second stages of acclimatization also include screening every 8 days, placing fry of roughly the same body length into the same pond for cultivation; spraying photosynthetic bacteria and EM bacteria into the pond every 8 days, and regularly disinfecting the pond. During the acclimatization period, dissolved oxygen is controlled at 7 mg / L, ammonia nitrogen is less than 0.05 mg / L, nitrite is less than 0.1 mg / L, and pH is 8.0.

[0081] (2) Construction of ecological aquaculture system

[0082] The same as the aquaculture system in Example 1.

[0083] (3) An ecological aquaculture system is used to raise large-sized fish fry after domestication. The method is as follows:

[0084] S1. Preparations before aquaculture: Check the operation of the airlift and water propulsion device, aeration equipment, sludge suction device, power aeration device, and online water quality monitoring system in the aquaculture system to ensure that they are operating normally.

[0085] S2. Disinfection: 20 days before the fish fry are released into the tank, disinfect the pond and the water tank with quicklime and tea seed cake; the amount of quicklime is 100 kg / mu and the amount of tea seed cake is 50 kg / mu. Soak the tea seed cake for 36 hours before use and then sprinkle it throughout the pond.

[0086] S3. Stocking fish fry: Select healthy, large-sized fish fry that have been domesticated and put them into a flowing water tank for intensive farming. On the first day, the water flow rate in the flowing water tank should be controlled at 6 m / min. After that, adjust the flow rate once every half month, increasing it by 1.2 m / min each time.

[0087] S4. Feeding Management: Feed large-particle feed three times a day at 8:00, 13:00 and 18:00. The total daily feed amount is 5% of the total weight of the fish in the flow tank. Feeding is carried out at the air-propelling end of the flow tank.

[0088] S5. Sludge suction: Sludge suction is performed within 2 hours after feeding. The feces and uneaten feed in the sludge collection area are sucked into the sewage treatment area for sewage treatment.

[0089] S6. Supporting Aquaculture Species: Filter-feeding fish, snails, and shellfish are stocked outside the flow channel, including silver carp (250g / kg).

[0090] 100 fish / mu for silver carp (250g / fish), 80 fish / mu for bighead carp (250g / fish), 400 fish / mu for crucian carp (50g / fish), 50kg / mu for river snails, and 40kg / mu for freshwater shellfish.

[0091] S7. Aquatic plant planting area: Construct 150㎡ of bio-floating beds per acre, and plant water spinach, whorled hydrangea and canna lilies in the bio-floating beds. The bio-floating beds are fixed with ropes and wooden stakes and can be moved to places that need purification.

[0092] S8. Daily Management: Observe the fish's activity and feeding behavior daily, and pay attention to the status of the online water quality monitoring system and equipment malfunction alarm system; promptly and harmlessly dispose of abnormal, injured, sick, and dead fish; use the disease detection system to test suspected diseased fish, administer appropriate medication, and keep good aquaculture records.

[0093] The aquaculture system of this invention was used for breeding, and the product was launched in August 2021, about three months earlier than the traditional breeding method, thus meeting market demand.

[0094] Example 3

[0095] An engineered recirculating aquaculture method for largemouth bass, comprising the following steps:

[0096] (1) Overwintering domestication of fish fry: including the first stage of domestication and the second stage of domestication;

[0097] The first stage of acclimatization involved placing largemouth bass fry with an average body length of 1 mm into a rearing pond equipped with a shade structure, aeration holes, and lights in December 2020. Acclimatization was conducted in a dark environment, with the lights turned on and the water surface vibrated during each feeding. The specific feeding method was as follows: Days 1-3: Feed 6 times a day with live brine shrimp; Days 4-6: Feed 6 times a day with a mixture of live brine shrimp and copepods in a 7:3 ratio; Days 7-9: Feed 6 times a day with a mixture of live copepods, rotifers, and powdered feed in a 7:1:2 ratio; Days 10-12: Feed 5 times a day with a mixture of live copepods, rotifers, and powdered feed in a 3:3:4 ratio; Days 13-15: Feed 5 times a day with a mixture of live copepods, rotifers, and powdered feed. Feeding ratios of rotifers, powdered feed, and small pellets are 3:5:2. From day 16 to 18, feed 5 times a day with rotifers, powdered feed, and small pellets in a ratio of 1:4:5. From day 19 to 21, feed 4 times a day with powdered feed and small pellets in a ratio of 2:8. From day 22 to 24, feed 4 times a day with small pellets and medium pellets in a ratio of 8:2. From day 25 to 27, feed 4 times a day with small pellets and medium pellets in a ratio of 4:6. From day 28 to 30, feed 4 times a day with small pellets and medium pellets in a ratio of 2:8. Each feeding should be 3% of the total weight of the fry. Mix all feeds thoroughly before feeding. Among them, powdered feed is feed ground into powder, with small pellets having a particle size of 0.6mm, medium pellets having a particle size of 1.5mm, and large pellets having a particle size of 2.5mm. At this time, the average body length of the fish fry exceeds 3.0cm.

[0098] The second stage of domestication involves transferring the fish fry obtained in the first stage to a workshop for continued temperature-controlled cultivation at 18°C. They are fed four times a day with a mixture of medium and large pellet feed. On the first day, the ratio of medium to large pellet feed is 8:2. Afterward, the proportion of large pellet feed in the mixture increases by 5% daily until it consists entirely of large pellet feed. Then, feeding is reduced to three times a day. Each feeding session accounts for 4% of the total weight of the fish fry. Once the average body length reaches 7cm, the fish fry are considered large-sized.

[0099] When feeding the above-mentioned feeds, an immune enhancer must be added to the corresponding feed. The immune enhancer consists of the following raw materials in parts by weight: 25 parts yeast glucan and 0.5 parts glycyrrhizic acid; the amount of the immune enhancer added is 0.03% of the total weight of the feed.

[0100] Routine Management: The first and second stages of acclimatization also include screening every 7 days, placing fry of roughly the same body length into the same pond for cultivation; every 8 days, photosynthetic bacteria and EM bacteria are sprayed into the pond, and the pond is disinfected regularly. During the acclimatization period, dissolved oxygen is controlled at 5 mg / L, ammonia nitrogen is less than 0.05 mg / L, nitrite is less than 0.1 mg / L, and pH is 7.5.

[0101] (2) Construction of ecological aquaculture system

[0102] The same as the aquaculture system in Example 1.

[0103] (3) An ecological aquaculture system is used to raise large-sized fish fry after domestication. The method is as follows:

[0104] S1. Preparations before aquaculture: Check the operation of the airlift and water propulsion device, aeration equipment, sludge suction device, power aeration device, and online water quality monitoring system in the aquaculture system to ensure that they are operating normally.

[0105] S2. Disinfection: 18 days before the fish fry are released into the tank, disinfect the pond and the water tank with quicklime and tea seed cake; the amount of quicklime is 90 kg / mu and the amount of tea seed cake is 45 kg / mu. Soak the tea seed cake for 30 hours before use and then sprinkle it throughout the pond.

[0106] S3. Stocking fish fry: Select healthy, large-sized fish fry that have been domesticated and put them into a flowing water tank for intensive farming. On the first day, the water flow rate in the flowing water tank should be controlled at 5 m / min. After that, adjust the flow rate once every half month, increasing it by 1.0 m / min each time.

[0107] S4. Feeding Management: Feed large-particle feed three times a day at 8:00, 13:00 and 18:00. The total daily feed amount is 3% of the total weight of the fish in the flow tank. Feeding is carried out at the air push end of the flow tank.

[0108] S5. Sludge suction: Sludge suction is performed within 1.8 hours after feeding. The feces and uneaten feed in the sludge collection area are sucked into the sewage treatment area for sewage treatment.

[0109] S6. Supporting Aquaculture Species: Filter-feeding fish, snails, and shellfish are stocked outside the flow channel, including silver carp (250g / kg).

[0110] 90 fish / mu for silver carp (250g / fish), 70 fish / mu for bighead carp (250g / fish), 300 fish / mu for crucian carp (50g / fish), 40kg / mu for river snails, and 30kg / mu for freshwater shellfish.

[0111] S7. Aquatic plant planting area: Construct 100㎡ of bio-floating beds per acre, and plant Hydrilla verticillata and Canna in the bio-floating beds. The bio-floating beds are fixed with ropes and wooden stakes and can be moved to places that need purification.

[0112] S8. Daily Management: Observe the fish's activity and feeding behavior daily, and pay attention to the status of the online water quality monitoring system and equipment malfunction alarm system; promptly and harmlessly dispose of abnormal, injured, sick, and dead fish; use the disease detection system to test suspected diseased fish, administer appropriate medication, and keep good aquaculture records.

[0113] The aquaculture system of this invention was used for breeding, and the product was launched in August 2021, about three months earlier than the traditional breeding method, thus meeting market demand.

[0114] Comparative Example 1: Fish fry with a body length of 0.9–1.2 mm (the body length of this invention) were subjected to the first stage of domestication using conventional methods. From day 1 to 10, they were fed copepods, cladocerans, and fish paste. After successful transition to fish paste starting on day 11, commercial feed was added to the fish paste, gradually reducing the amount of fish paste until they were fed only commercial feed. When the average body length reached 3 cm, the survival rate and disease rate of the first stage of domestication were statistically analyzed. The results are shown in Table 1.

[0115] Table 1 Comparison results of the first stage of domestication

[0116] Item Incidence (%) Survival rate (%) Example 1 41.2 58.8 Example 2 43.1 56.9 Example 3 40.7 59.3 Comparative Example 1 79.8 20.2

[0117] Table 1 shows that the traditional method of acclimatizing fish fry with a body length of 0.9-1.2 mm results in a high morbidity rate and a low survival rate (only 20.2%). However, the first-stage acclimatization survival rate of this invention is as high as 55% or more. It is evident that the acclimatization method of this invention is superior to the traditional method, solving the problems of late acclimatization time and high breeding costs. It allows fish fry to switch to feed earlier, reduces the need for live insects, and lowers breeding costs.

[0118] Comparative Example 2: No immune enhancer was added in the first and second stages of acclimatization. Other acclimatization steps were the same as in Example 1. The survival rate and morbidity rate of the first and second stages of acclimatization were statistically analyzed. The results are shown in Table 2.

[0119] Comparative Example 3: The immune enhancer does not contain yeast glucan, but only glycyrrhizic acid. Other domestication steps are the same as in Example 1. The survival rate and morbidity rate of the first and second stages of domestication are statistically analyzed, and the results are shown in Table 2.

[0120] Comparative Example 4: The immune enhancer does not contain glycyrrhizic acid, but only yeast glucan. Other domestication steps are the same as in Example 1. The survival rate and morbidity rate of the first and second stages of domestication are statistically analyzed, and the results are shown in Table 2.

[0121] Table 2 Comparison of domestication results

[0122]

[0123] Table 2 shows that the immune enhancer of this invention can reduce stress, improve resistance, reduce disease occurrence, and thus improve the survival rate of acclimatized fish. Specifically, the yeast glucan and glycyrrhizic acid in the immune enhancer work together to effectively alleviate oxidative stress on the liver of fish fry caused by changes in feed and environment, preventing liver stress damage and lesions that lead to reduced disease resistance, thereby reducing the incidence of disease and improving the survival rate of acclimatized fish.

[0124] Comparative Example 5

[0125] In 2021, an ecological aquaculture system (5 mu in pond area, with a wastewater treatment area including five ponds and two dams: a first sedimentation pond, a first filtration dam, a second sedimentation pond, an aeration pond, a second filtration dam, a microbial treatment pond, and an aquatic plant purification pond) was constructed in Shanglin County, Nanning City, Guangxi Province, according to Example 1. Fish fry domesticated in Example 1 were then raised there. Simultaneously, as a comparison, a traditional ecological aquaculture system (5 mu in pond area, but with a wastewater treatment area containing only three ponds and two dams: a sedimentation pond, a first filtration dam, an aeration pond, a second filtration dam, and an aquatic plant purification pond) was constructed nearby, and fish fry domesticated in Example 1 were raised there as well. Wastewater treatment was tested in the second month after aquaculture (samples treated in the aquatic plant purification pond were taken for testing). The results are shown in Table 3.

[0126] Table 3 Comparison of Wastewater Treatment Status

[0127] Item Example 1 Comparative Example 5 mg / L of suspended matter 66 89 pH value 7.20 9.50 mg / L of ammonia nitrogen 0.72 2.30 mg / L of total phosphorus (as P) 0.51 0.99 mg / L of total nitrogen (as N) 4.01 6.87

[0128] This invention's aquaculture system can efficiently treat fish farm wastewater, with treatment results meeting national discharge standards (suspended solids ≤85%, pH 6-9, ammonia nitrogen ≤2%, total phosphorus (as P) ≤0.8%, total nitrogen (as N) ≤5.0%), superior to traditional treatment methods. Aquaculture using this system can achieve intensive, intelligent, green, and ecological aquaculture results.

[0129] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for engineered recirculating aquaculture of largemouth bass, characterized in that, This includes the overwintering and domestication of fish fry, the construction of an ecological aquaculture system, and the use of the ecological aquaculture system to raise the domesticated large-sized fish fry. The overwintering acclimatization process begins with fry measuring 0.9-1.2 mm in body length and progresses to larger fry measuring 6-8 cm in body length, adapting them to formulated feed. The acclimatization period lasts from November / December to March of the following year. The acclimatization process is divided into two stages: a first stage and a second stage. The first stage of acclimatization involves placing largemouth bass fry with a body length of 0.9~1.2mm into a rearing pond equipped with a shade structure, aeration holes, and lights. Acclimatization is carried out in a dark environment. Each time they are fed, the lights are turned on and the water surface is tapped to create vibration. The specific feeding method is as follows: Feed live brine shrimp 5-7 times a day for days 1-3. From day 4 to day 6, feed 5 to 7 times a day with live brine shrimp and copepods as live food, with a ratio of 7:3 between the two. From day 7 to day 9, feed 5 to 7 times a day with live copepods, rotifers and powdered feed in a ratio of 7:1:

2. On days 10-12, feed 4-5 times a day with live copepods, rotifers and powdered feed in a ratio of 3:3:

4. From day 13 to day 15, feed 4 to 5 times a day, feeding rotifers, powdered feed and small pellet feed in a ratio of 3:5:

2. From day 16 to 18, feed 4 to 5 times a day, using rotifers, powdered feed and small pellet feed in a ratio of 1:4:

5. From day 19 to 21, feed 4 to 5 times a day, using powdered feed and small pellet feed in a ratio of 2:

8. From day 22 to 24, feed 4 to 5 times a day, using small and medium-sized pellet feed in a ratio of 8:

2. From day 25 to 27, feed 4 to 5 times a day, using small and medium-sized pellets in a ratio of 4:

6. From day 28 to 30, feed 4 to 5 times a day, using small and medium-sized pellets in a ratio of 2:

8. The second stage of domestication involves transferring the fish fry obtained from the first stage of domestication to a workshop for continued temperature-controlled cultivation at 16-19°C. The fish are fed 4-5 times a day with a mixture of medium and large pellet feed. On the first day, the ratio of the two feeds is 8:

2. After that, the proportion of large pellet feed in the mixture increases by 5%-10% each day until it is entirely large pellet feed. Then, the feeding is changed to 3 times a day, and the fish are raised until they reach a body length of 6-8cm, which yields the large-sized fish fry. When feeding the above-mentioned feeds, an immune enhancer must be added to the corresponding feed. The immune enhancer comprises the following raw materials in parts by weight: 20-30 parts yeast glucan and 0.1-0.8 parts glycyrrhizic acid; the amount of the immune enhancer added is 0.01-0.04% of the total weight of the feed. The ecological aquaculture system includes a pond and a wastewater treatment area. The wastewater treatment area includes: a first sedimentation tank, a first filter dam, a second sedimentation tank, an aeration tank, a second filter dam, a microbial treatment tank, and an aquatic plant purification tank. The first sedimentation tank is connected to the wastewater collection area via a sludge suction device. The first sedimentation tank is connected to the second sedimentation tank via the first filter dam, and the outlet of the second sedimentation tank is connected to the inlet of the aeration tank. The aeration tank is connected to the microbial treatment tank via the second filter dam. An aeration device is provided at the bottom of the aeration tank, and the outlet of the microbial treatment tank is connected to the inlet of the aquatic plant purification tank. A heating pipe is provided at the bottom of the microbial treatment tank, and a protective pipe is provided outside the heating pipe. The heating pipe is connected to a heating device.

2. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, The powdered feed is made by grinding feed into powder; the small pellet feed has a particle size of 0.5~0.9mm, the medium pellet feed has a particle size of 1~1.9mm, and the large pellet feed has a particle size of 2~3mm.

3. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, In the first stage of domestication, the total amount of feed given each time should be 2% to 5% of the total weight of the fish fry. Before feeding, the feed should be mixed evenly.

4. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, In the second stage of domestication, the total amount of feed given each time accounts for 3% to 5% of the total weight of the fish fry fed.

5. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, The first and second stages of domestication also include screening every 5-8 days, placing fish fry of uniform size into the same pond for cultivation; spraying photosynthetic bacteria and EM bacteria into the pond every 7-8 days, and regularly disinfecting the pond.

6. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, The pond is equipped with a flowing water channel, an aquatic plant planting area, a powered aeration device, and a retaining wall. The flowing water channel is a long, open channel with open ends, located near and parallel to the edge of the pond. A waste collection area is located at the rear end of the channel. The channel is divided into multiple aquaculture zones, each equipped with an air-lifting and water-propulsing device at its front end and an aeration device inside each zone. The aquatic plant planting area is located within the pond. The powered aeration devices are located at the four corners of the pond, aligned with the water flow direction of the flowing water channel. The retaining wall is constructed of bricks, iron frames, or mesh, located at the rear end of the flowing water channel and perpendicular to it. The aquaculture system also includes an equipment fault alarm system, a disease detection system, and an online water quality monitoring system. The equipment fault alarm system is connected to the air-lifting and water-propulsing device and the aeration device. The online water quality monitoring system is connected to the flowing water channel.

7. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, The first filtration dam is provided with, in sequence from the first sedimentation tank to the second sedimentation tank, a filter screen layer, an organic matter degradation layer, and an ammonia nitrogen adsorption layer; the second filtration dam is provided with, in sequence from the aeration tank to the microbial treatment tank, a filter screen layer, an organic matter degradation layer, and an ammonia nitrogen adsorption layer; the organic matter degradation layer is composed of biological packing material, and the surface of the biological packing material is covered with a microbial membrane capable of degrading organic matter; the ammonia nitrogen adsorption layer is filled with zeolite sheets.

8. The method for engineered recirculating aquaculture of largemouth bass according to claim 1, characterized in that, The steps for raising the overwintered, domesticated large-sized fish fry using the aforementioned ecological aquaculture system are as follows: (1) Preparation before breeding: Check the operation of the air lift water pusher, oxygenation equipment, sewage suction device, power oxygenation device and water quality online monitoring system in the breeding system to ensure that they can operate normally; (2) Disinfection: 15 to 20 days before the fish fry are released into the tank, the pond and the water tank are disinfected with quicklime and tea seed cake; the amount of quicklime is 75 to 100 kg / mu and the amount of tea seed cake is 40 to 50 kg / mu. When using, the tea seed cake is sprinkled throughout the pond. (3) Stocking fish fry: Select healthy, large-sized fish fry that have been domesticated and put them into a flowing water tank for intensive farming. On the first day, the water flow rate in the flowing water tank is controlled at 4~6 m / min. After that, the flow rate is adjusted once every half month, increasing by 0.7~1.2 m / min each time. (4) Feeding management: Feed large-particle feed three times a day at 7-8 am, 12-13 pm and 5-18 pm respectively. The total amount of feed per day is 2% to 5% of the total weight of the fish in the water tank. Feeding is carried out at the air push end of the water tank. (5) Sewage suction: Sewage suction is performed 1.5 to 2 hours after feeding. The feces and uneaten feed in the sewage collection area are sucked into the sewage treatment area for sewage treatment through the sewage suction device. (6) Supporting species: Filter-feeding fish, snails and shellfish are stocked outside the water tank, including 50-100 silver carp / mu, 50-80 bighead carp / mu, 200-400 crucian carp / mu, 30-50 kg snails / mu, and 20-40 kg freshwater shellfish / mu. (7) Aquatic plant planting area: Construct 75-150㎡ of biological floating beds per mu, and plant rice, water spinach, whorled hydrangea and / or canna in the biological floating beds. The biological floating beds are fixed with ropes and wooden stakes. (8) Daily management: Observe the fish’s activity and feeding every day, and pay attention to the status of the online water quality monitoring system and the equipment fault alarm system; promptly and harmlessly dispose of abnormal, injured, sick and dead fish; use the disease detection system to detect suspected diseased fish, administer appropriate medication, and keep good aquaculture records.

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