Micropterus salmoides fry breeding method based on oxygen generator

Abstract

The invention provides a largemouth micropterus salmoides fry breeding method based on an oxygen generator, and belongs to the technical field of aquatic product high-density breeding, and the technical scheme is that the largemouth micropterus salmoides fry breeding method comprises the steps that a PP material circular breeding pond with the diameter being 1.2-1.6 m and the height being 0.7-0.9 m is arranged, and a micropore aeration pipe connected with the oxygen output end of the oxygen generator is laid at the pond bottom; the oxygen generator generates oxygen with the purity of 90%-95% through a molecular sieve adsorption method, releases bubbles of 0.1-0.5 mm, and maintains the dissolved oxygen of the water body to be 9-11 mg / L and the water temperature to be 22-27 DEG C; putting fish fries according to the density of 80,000-120,000 fish fries per cubic meter of water; sequentially feeding live fairy shrimps for 7-10 days and frozen water fleas for 2-4 days, then replacing the domesticating compound feed for 14-15 days in a gradient manner, and meanwhile, adding a compound microbial preparation into the breeding pond every day; 15%-25% of aquaculture water is replaced by a circulating water system every day. The method realizes ultra-high density seedling raising, obviously shortens the period and improves the survival rate.

Description

Technical Field

[0001] This invention belongs to the field of high-density aquaculture technology, and more specifically, this invention relates to a method for cultivating largemouth bass fry based on an oxygenator. Background Technology

[0002] Largemouth bass, an important freshwater economic fish, is traditionally raised using blowers to aerate the water, maintaining dissolved oxygen levels at 4-5 mg / L. This dissolved oxygen level is insufficient for high-density aquaculture, leading to slow growth and reduced disease resistance in the fry. Existing aquaculture facilities mostly use concrete structures, which suffer from long construction periods, poor flexibility, and susceptibility to corrosion. Furthermore, they cannot achieve precise and coordinated control of water temperature and dissolved oxygen, thus limiting the efficiency of large-scale fry production. Summary of the Invention

[0003] One object of the present invention is to address at least the aforementioned deficiencies and to provide at least the advantages that will be described later.

[0004] This invention provides a method for cultivating largemouth bass fry based on an oxygen generator. By using an oxygen generator in conjunction with a PP material pond, it achieves high-density culture with dissolved oxygen ≥9mg / L (80,000-120,000 fish / cubic meter), shortens the seedling cultivation cycle, improves the survival rate, and facilitates large-scale production.

[0005] This invention provides a method for cultivating largemouth bass fry based on an oxygenator, comprising the following steps: A circular cultivation tank constructed of PP material is configured, the diameter of which is 1.2 meters to 1.6 meters and the height is 0.7 meters to 0.9 meters; Microporous aeration pipes are laid at the bottom of the cultivation tank, and the microporous aeration pipes are connected to the oxygen output end of the oxygen generator; the oxygen generator generates oxygen with a purity of 90% to 95% through molecular sieve adsorption, and releases bubbles with a diameter of 0.1 mm to 0.5 mm through the microporous aeration pipes; the dissolved oxygen concentration in the cultivation tank is maintained at 9 mg / L to 11 mg / L, and the water temperature is maintained at 22℃ to 27℃; Stocking density should be 80,000 to 120,000 largemouth bass fry per cubic meter of water. The cultivation and feeding stages include: feeding live Artemia for 7 to 10 days, feeding frozen Daphnia for 2 to 4 days, and acclimating to formulated feed for 7 to 10 days; during the cultivation and feeding stages, compound microbial agents are added to the cultivation tank daily at a rate of 0.1 g / m3 to 0.3 g / m3. Replace 15% to 25% of the aquaculture water daily using a circulating water system or external water source.

[0006] Preferably, the cultivation tanks are arranged in two parallel rows, with 5 to 12 cultivation tanks in each row; each cultivation tank is equipped with independent inlet and outlet pipes, microporous aeration pipes, and temperature control equipment; the circulating water system is connected to a microfilter, and the microfilter has a filtration accuracy of 20 micrometers to 50 micrometers.

[0007] Preferably, the acclimatization stage uses a gradual replacement method, starting from the last day of feeding pure frozen daphnia, gradually replacing the frozen daphnia with compound feed, reducing the amount of frozen daphnia by 20% to 30% each day and increasing the amount of compound feed by an equal amount, with the cultivation period being 18 to 24 days.

[0008] Preferably, the oxygen concentrator performs the following process flow: The air compressor pressurizes ambient air to 0.55MPa to 0.65MPa, and outputs compressed air with a dew point ≤ -40℃; Compressed air is dried by a refrigerated dryer to remove liquid water before entering a dual-tower adsorption unit equipped with lithium-based zeolite molecular sieves. The dual-tower adsorption unit performs a pressure adsorption-depressurization desorption cycle: the adsorption tower adsorbs nitrogen for 25 to 30 seconds at 0.5 MPa to 0.6 MPa, and the desorption tower releases nitrogen at 0.15 MPa to 0.25 MPa. The pressure equalization operation is performed for 0.5 to 1.5 seconds between the two towers to ensure that the oxygen concentration fluctuation rate is ≤3%. After the produced oxygen is stabilized by a buffer tank, it passes through a series of activated carbon filters and polytetrafluoroethylene membrane filters to remove particles larger than 0.3 micrometers. The final output oxygen purity is 90% to 95%, and the flow rate is adjusted by a flow meter to an oxygen supply rate of 0.8 L / min to 1.5 L / min per cubic meter of cultivation water before being connected to a microporous aeration pipe.

[0009] Preferably, the independent inlet and outlet pipelines include a drain outlet at the bottom of the cultivation tank and an inlet at the top of the tank wall. The drain outlet is connected to an external circulating water system via a drain pipe. The microporous aeration pipe is laid in a U-shape straight pipe at the bottom of the cultivation tank and connected to the filter output end of the oxygen generator via a pressure-resistant hose. The microporous aeration pipe is 1-2 cm away from the bottom wall of the cultivation tank. A dissolved oxygen sensor is installed in the middle of the cultivation tank. The temperature control equipment includes a heating cable located in the cultivation tank and a temperature sensor in the middle of the cultivation tank. The heating cable has a power of 300W to 400W per cubic meter of water. The inlet and outlet pipes, microporous aeration pipes, and temperature control equipment are linked and controlled by a PLC controller to perform the following operations: When the temperature sensor reading is below 22℃, start the heating cable until the water temperature reaches 25℃. When the dissolved oxygen sensor reading remains below 9 mg / L for 2 minutes, increase the oxygen concentrator's output pressure by 0.056 MPa to 0.1 MPa; when the dissolved oxygen sensor reading remains above 10.5 mg / L for 2 minutes, decrease the output pressure in increments of 0.02 MPa until the pressure returns to the oxygen concentrator's base operating pressure (0.55-0.65 MPa) or the DO drops below 10.5 mg / L. The drainage process is initiated daily at 18:00, with a constant drainage volume of 15% to 25% of the culture tank volume.

[0010] Preferably, the heating cable is installed on the lower side wall of the cultivation tank and covered with a removable stainless steel mesh cover with a mesh diameter of 0.8 mm to 1.0 mm. The mesh cover is embedded in the first branch pipe of the circulating water system, and the outlet of the first branch pipe is located at the bottom of the mesh cover, which can control the water flow velocity to 0.15 m / s to 0.25 m / s. During the operation of the heating cable, the first branch pipe is started to supply water simultaneously, so that a directional water flow is formed inside the mesh cover. The bottom of the mesh cover is 5 cm to 10 cm away from the bottom of the tank, and the surface temperature of the heating cable is monitored in real time by a thermocouple and limited to 35°C to 38°C.

[0011] Preferably, a compound microbial preparation is added to the cultivation pond daily at a rate of 0.1 g / m³ to 0.3 g / m³. The compound microbial preparation contains 5-10 parts by weight of Lactobacillus plantarum, 5-10 parts of Lactobacillus acidophilus, 10-20 parts of Bacillus subtilis, 5-10 parts of Clostridium butyricum, and 5-10 parts of Rhodopseudomonas palustris. The preparation is added before feeding at 8:00 AM daily and continues until the end of the acclimatization stage.

[0012] Preferably, the viable counts of *Lactobacillus plantarum* are 5 × 10⁹ CFU / g, *Lactobacillus acidophilus* are 5 × 10⁹ CFU / g, *Bacillus subtilis* are 1 × 10¹⁰ CFU / g, *Clostridium butyricum* are 5 × 10⁹ CFU / g, and *Rhodopseudomonas palustris* are 1 × 10⁸ CFU / g.

[0013] Preferably, an LED light strip with a wavelength of 590 to 595 nanometers is installed on the top of the cultivation tank, with a light intensity of 300 to 500 lux; the light strip is turned on from 18:00 to 6:00 the next day.

[0014] Preferably, a microbial agent injection pipe is added at the water inlet at the bottom of the mesh cover, and the injection pipe is connected to the composite microbial agent storage tank; the outlet of the second branch pipe of the circulating water system is close to the bottom wall of the cultivation tank and flows towards the drain outlet.

[0015] The present invention has at least the following beneficial effects: This invention achieves high-density aquaculture (80,000-120,000 fish / cubic meter) with dissolved oxygen ≥9mg / L through an oxygen generator in conjunction with a PP material pond, shortening the seedling cycle, improving the survival rate, and facilitating large-scale production.

[0016] This invention also effectively controls water quality stability through temperature control and dissolved oxygen linkage. The non-contact bottom wall of the microporous aeration pipe reduces disturbance of sediment, which is conducive to maintaining water quality stability and improving the growth rate and survival rate of fish fry.

[0017] This invention uses a heating cable installed on the lower side wall of the cultivation tank, an external detachable stainless steel mesh cover, and the outlet of the first branch pipe of the circulating water system located at the bottom of the mesh cover. This effectively regulates the water temperature, reduces the deposition and spread of dirt, avoids affecting seedling cultivation, and helps improve growth rate and survival rate.

[0018] This invention utilizes a compound microbial preparation to facilitate the degradation of ammonia nitrogen, maintain water quality stability, promote fry growth, and increase survival rate, thus meeting the needs of high-density fry cultivation. Specific wavelength light irradiation inhibits algal nighttime oxygen consumption, reducing dissolved oxygen (DO) fluctuations and also enhances the abundance of compound microorganisms and fry growth. This addresses the problem of fry surfacing and agglomeration damage caused by nighttime dissolved oxygen fluctuations, thereby improving fry growth and survival rates.

[0019] This invention utilizes directional water flow at the bottom of the mesh cover to instantly diffuse microbial agents, reducing the impact of sedimentation. During drainage, the water flow from the second branch pipe is used to flush and stir up sediment at the bottom of the pool, improving sewage discharge efficiency.

[0020] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of one implementation of the cultivation equipment used in the oxygen generator-based largemouth bass seedling cultivation method of the present invention. Figure 2 This is an enlarged schematic diagram of another implementation of the cultivation equipment used in the oxygen generator-based largemouth bass fry cultivation method of the present invention. Figure 3 This is a schematic diagram illustrating the field effect of the largemouth bass fry cultivation method based on an oxygen generator described in this invention. Figure 4 for Figure 3 A close-up view of the cultivation pool in the image; Figure 5 Image showing the results on day 2 after introducing largemouth bass yolk fry; Figure 6 Image showing the effect of raising largemouth bass yolk fry on day 15; The components include: 1. Inlet pipe; 2. Inlet; 3. Culture tank; 4. Flexible hose; 5. Microporous aeration pipe; 6. Outlet; 7. Drain pipe; 8. Water pump; 9. Oxygen generator; 10. Circulating water system; 11. First branch pipeline; 12. Heating cable; 13. Stainless steel mesh cover; 14. Microfilter; 15. External water source pipeline. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0023] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] The present invention provides a method for cultivating largemouth bass fry based on an oxygen generator, comprising the following steps: constructing a circular cultivation tank made of PP material, the tank having a diameter of 1.2 to 1.6 meters and a height of 0.7 to 0.9 meters; laying microporous aeration pipes at the bottom of the cultivation tank, the microporous aeration pipes being connected to the oxygen output end of an oxygen generator; the oxygen generator generating oxygen with a purity of 90% to 95% through molecular sieve adsorption, and releasing it through the microporous aeration pipes with a diameter of 0.1 mm. Bubbles ranging from 0.5 mm in diameter; maintain dissolved oxygen concentration in the rearing pond at 9 mg / L to 11 mg / L and water temperature at 22°C to 27°C; stock 80,000 to 120,000 largemouth bass larvae per cubic meter of water; the rearing and feeding stages include: feeding live brine shrimp for 7 to 10 days, feeding frozen daphnia for 2 to 4 days, and acclimating to formulated feed for 7 to 10 days; and replacing 15% to 25% of the aquaculture water daily through a circulating water system.

[0025] Example 1 A method for cultivating largemouth bass fry based on an oxygen concentrator 9 includes the following steps: See Figure 1 and Figure 3 , Figure 4 As shown, the cultivation pool 3 is configured as follows: The circular cultivation pool 3 is constructed of PP material, with a diameter of 1.5 meters and a height of 0.8 meters.

[0026] Oxygen supply system setup: A microporous aeration pipe 5 is laid at the bottom of the cultivation tank 3, and the microporous aeration pipe 5 is connected to the oxygen output end of the oxygen generator 9; the oxygen generator 9 generates oxygen with a purity of 95% through molecular sieve adsorption, and releases bubbles with a diameter of 0.2-0.5 mm through the microporous aeration pipe 5 (50μmPTFE microporous aeration pipe 5); maintain the dissolved oxygen concentration in the water of the cultivation tank 3 at about 10mg / L and the water temperature at about 25℃.

[0027] Stocking density: Stock at a density of 100,000 largemouth bass larvae per cubic meter of water. See [reference needed]. Figure 5 The image shows the effect after cultivation on the second day. Figure 6 This is a picture showing the effect after 15 days of cultivation.

[0028] Feeding Management: Feed live Artemia for 8 days; feed frozen Daphnia for 3 days; acclimate to formulated feed for 9 days, using a gradual replacement method during the acclimatization period: starting from the last day of feeding pure frozen Daphnia, gradually replace the frozen Daphnia with formulated feed, reducing the frozen Daphnia by 20% to 30% daily and increasing the amount of formulated feed by an equal amount. Additionally, add a compound microbial preparation to culture tank 3 daily at a rate of 0.2 g / m³ (each 1 g of compound microbial preparation is added to 200 mL of sterile water, gently shaken to disperse evenly before use). The compound microbial preparation includes 7 parts by weight of Lactobacillus plantarum (5 × 10⁻⁶ live bacteria). 9 CFU / g), 7 samples of Lactobacillus acidophilus and 15 samples of Bacillus subtilis (live count 1×10¹). 0 (CFU / g); the total cultivation period is 20 days.

[0029] Water treatment system: The circulating water system 10 replaces 20%-25% of the aquaculture water daily. The upper end of the circulating water system 10 is connected to an external water source pipe 15 as a backup water source, but the self-circulating water body is preferred for replacement. The breeding ponds 3 are arranged in two parallel rows, with 5 breeding ponds 3 in each row. Each breeding pond 3 is equipped with an independent inlet and outlet pipe 7, a microporous aeration pipe 5, and a temperature control device. The circulating water system 10 is connected to a microfilter 14, and the filtration accuracy of the microfilter is 35 microns.

[0030] Oxygen generator process 9: The air compressor pressurizes the ambient air to 0.6MPa, and the output compressed air dew point is ≤-40℃; the compressed air passes through a refrigerated dryer to remove liquid water and enters a dual-tower adsorption device equipped with lithium-based zeolite molecular sieves; the dual-tower adsorption device performs a pressure adsorption-depressurization desorption cycle: the adsorption tower adsorbs nitrogen at 0.55MPa for 28 seconds; the desorption tower releases nitrogen at 0.2MPa; a 1.0-second pressure equalization operation is performed between the two towers to ensure that the oxygen concentration fluctuation rate is ≤3%; after the produced oxygen is stabilized by a buffer tank, it passes through a series of activated carbon filters and polytetrafluoroethylene membrane filters to remove particles larger than 0.3 microns; the final output oxygen purity is 95%, and the flow rate is adjusted to 1.2L / min per cubic meter of cultivation water by a flow meter, and then connected to the microporous aeration pipe 5.

[0031] Example 2 A method for cultivating largemouth bass fry based on an oxygen generator 9, using cultivation equipment and methods basically the same as in Example 1, with the following differences: It also includes PLC-linked control of water temperature and dissolved oxygen, and a design where the microporous aeration pipe 5 is 1.5cm away from the bottom wall of the cultivation tank 3. Specifically: Independent inlet and outlet pipes 7 include a drain outlet 6 at the bottom of the cultivation tank 3 and an inlet 2 at the top of the tank wall. The inlet 2 is connected to the outlet of an external circulating water system 10 via an inlet pipe 1, and the drain outlet 6 is connected to the external circulating water system 10 via a drain pipe 7. A water pump 8 is installed on the drain pipe 7 to pump the bottom water of the cultivation tank 3 into the circulating water system 10 for filtration and purification; the microporous aeration pipe 5 is laid in a U-shape straight pipe at the bottom of the cultivation tank 3, 1.5cm away from the bottom wall; it is connected to the filter output end of the oxygen generator 9 via a pressure-resistant hose 4; a dissolved oxygen sensor is installed in the middle of the cultivation tank 3; the temperature control device includes components located in the cultivation tank 3... The heating cable 12 is located inside the water tank 3, and the temperature sensor is located in the middle of the tank. The heating cable 12 has a power of 350W per cubic meter of water. The inlet and outlet pipes 7, the microporous aeration pipe 5, and the temperature control equipment are controlled by a PLC controller to perform the following operations: When the temperature sensor detects a value below 22℃, the heating cable 12 is activated until the water temperature reaches 25℃; when the dissolved oxygen sensor detects a value below 9mg / L for 2 minutes, the output pressure of the oxygen generator 9 is increased by 0.1MPa (the absolute pressure of gauge pressure 0.1MPa is 0.2MPa); when the dissolved oxygen sensor detects a value above 10.5mg / L for 2 minutes, the output pressure is reduced in a gradient of 0.02MPa per cycle until the pressure returns to the basic working pressure of the oxygen generator 9 (0.6MPa) or the DO drops below 10.5mg / L; the drainage program is activated at 18:00 every day, and the drainage volume is 20-25% of the volume of the cultivation tank 3.

[0032] Example 3 A method for cultivating largemouth bass fry based on an oxygenator 9, using cultivation equipment and methods basically the same as in Example 2, except that it also includes a net cover and a first branch pipe 11, and a heating cable 12 located on the lower side wall of the pool. See [link to relevant documentation]. Figure 2 As shown, specifically: the heating cable 12 is installed on the lower side wall of the cultivation tank 3, and is covered by a detachable stainless steel mesh cover 13 with a mesh diameter of 0.9 mm; the mesh cover is embedded in the first branch pipe 11 of the circulating water system 10, the outlet of the first branch pipe 11 is located at the bottom of the mesh cover, and the inlet of the first branch pipe 11 is connected to the inlet 2 at the top of the tank wall, which can start the water flow speed of 0.2 m / s; during the operation of the heating cable 12, the first branch pipe 11 is started to supply water simultaneously, so that a directional water flow is formed inside the mesh cover; the bottom of the mesh cover is 6 cm away from the bottom of the tank; the surface temperature of the heating cable 12 is monitored in real time by a thermocouple and limited to 36℃.

[0033] Example 4 A method for cultivating largemouth bass fry based on an oxygenator is used, and the cultivation equipment and methods are basically the same as in Example 3, except that the compound microbial preparation is different. Specifically: The compound microbial preparation contains the following components by weight: 7 parts of Lactobacillus plantarum (5×10⁹ CFU / g live bacteria), 7 parts of Lactobacillus acidophilus (5×10⁹ CFU / g live bacteria), 15 parts of Bacillus subtilis (1×10¹⁰ CFU / g live bacteria), 7 parts of Clostridium butyricum (5×10⁹ CFU / g live bacteria), and 7 parts of Rhodopseudomonas palustris (1×10⁸ CFU / g live bacteria). Add compound microbial preparation to the breeding pond daily at a rate of 0.2 g / m3 (add 1 g of compound microbial preparation to 200 mL of sterile water, shake gently to disperse evenly before use); add before feeding at 8:00 a.m. daily, and continue until the end of the acclimatization stage.

[0034] Example 5 A method for cultivating largemouth bass fry based on an oxygenator is used, and the cultivation equipment and methods are basically the same as those in Example 4. The difference is that it also includes installing a 593-nanometer wavelength LED light strip on the top of the cultivation pond, with a light intensity of 400 lux; the light strip is turned on from 18:00 to 6:00 the next day.

[0035] Example 6 A method for cultivating largemouth bass fry based on an oxygenator is used, and the cultivation equipment and method are basically the same as those in Example 5. The difference is that: a microbial agent injection pipe is added at the water inlet at the bottom of the net cover, and the injection pipe is connected to a compound microbial agent storage tank; while adding compound microbial agent to the cultivation tank every day, the first branch pipe is opened to inject water to promote the immediate diffusion of microbial agent; the outlet of the second branch pipe of the circulating water system is close to the bottom wall of the cultivation tank and flows towards the drain outlet.

[0036] Comparative Example 1 It adopts the industry-standard largemouth bass fry breeding process, using traditional blower aeration and concrete tanks. Specific steps: Cultivation tank configuration: The cultivation tank is constructed of reinforced concrete in a circular shape (wall thickness 15cm), with a diameter of 1.5 meters and a height of 0.8 meters; Construction period: 28 days (including curing time), the inner wall of the pool is coated with an epoxy resin anti-corrosion layer.

[0037] Oxygenation system: Perforated aeration pipes (3mm aperture) are installed at the bottom of the pool and connected to a Roots blower (model RC-80); the blower outputs air volume of 5m3 / min, with bubble diameter of 2-3mm to maintain a dissolved oxygen concentration of 4.5mg / L in the water (measured value range of 4.2-4.8mg / L), and the water temperature fluctuates naturally (22-28℃).

[0038] Stocking and feeding: 100,000 largemouth bass fry per cubic meter of water (same as Example 1). Feeding procedure: Feed live Artemia for 8 days; feed frozen Daphnia for 3 days; feed formulated feed for 14 days, then directly switch to formulated feed (no transition period); add compound microbial preparation to the rearing tank daily at a rate of 0.2 g / m³. 3 (Add 200mL of sterile water to each 1g of compound microbial preparation, gently shake to disperse evenly before use). The compound microbial preparation includes 7 parts by weight of Lactobacillus plantarum (5×10⁻⁶ viable bacteria). 9 CFU / g), 7 samples of Lactobacillus acidophilus and 15 samples of Bacillus subtilis (live count 1×10¹). 0 (CFU / g); the total cultivation period is 20 days.

[0039] Water treatment system (same as in Example 1).

[0040] Experiment 1 1. Experimental conditions and design specifications Site environment: Closed recirculating aquaculture workshop, ambient temperature 25±2℃, relative humidity 60-70%.

[0041] Water source treatment: municipal water source, filtered through a sand filter tank (50μm), then sterilized with ultraviolet light (30mJ / cm²), and the salinity is adjusted to 0.2‰ (simulating fresh water).

[0042] The test fry were largemouth bass fry (0 days old, body length 0.5±0.1cm) from the same batch, provided by the hatchery.

[0043] Group settings: Testing cycle: Sampling is conducted daily at 8:00 AM, with key indicators monitored continuously for 24 hours (dissolved oxygen / temperature recorded every 10 minutes). 2. Testing method 3. The measurement results are shown in Table 1.

[0044] Table 1: Comparison of core aquaculture performance (mean ± SD, n=3) The experimental results showed that in Comparative Example 1 (blower), the average dissolved oxygen (DO) was 4.5 mg / L, which suddenly dropped to 2.1 mg / L at night, leading to a high surfacing rate. The sudden change in feed also caused a decrease in feeding rate, affecting survival rate. Example 1 maintained DO at 10.2 ± 0.3 mg / L. Microporous aeration resulted in high oxygen utilization, and the gas-liquid contact area of ​​microporous aeration (0.2 mm bubbles) was approximately 12 times larger than that of blower aeration (2-3 mm bubbles). Dissolved oxygen > 9 mg / L increased the metabolic rate of fry and improved SGR. Example 2 demonstrated that temperature control and dissolved oxygen linkage effectively stabilized water quality. The non-contact design of the microporous aeration pipes reduced disturbance to sediment, which helped maintain water quality stability and improve fry growth and survival rates. Example 3: Heating cables are installed on the lower side wall of the cultivation tank, covered by a removable stainless steel mesh cover. The outlet of the first branch pipe of the circulating water system is located at the bottom of the mesh cover, effectively regulating water temperature, reducing dirt deposition and diffusion, avoiding impact on seedling cultivation, and improving growth and survival rates. Example 4: Compound microbial agents are used to facilitate the degradation of ammonia nitrogen, maintain water quality stability, promote seedling growth, and improve survival rates, meeting the needs of high-density seedling cultivation. Example 5: Under 590-595nm light, the abundance of *Rhodopseudomonas pulverans* is increased, and fish fry growth is promoted. Algae density decreases, reducing nighttime oxygen consumption and minimizing damage from fish surfacing. Example 6: The microbial agents are instantly diffused by directional water flow at the bottom of the mesh cover, preventing sedimentation failure. During drainage, the water flow from the second branch pipe flushes and stirs up sediment at the bottom of the tank, improving sewage discharge efficiency, further contributing to maintaining water quality stability, promoting seedling growth, and improving survival rates, meeting the needs of high-density largemouth bass seedling cultivation.

[0045] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Further modifications can be readily implemented by those skilled in the art.

Claims

1. A method for cultivating largemouth bass fry based on an oxygenator, characterized in that, Includes the following steps: A circular cultivation tank constructed of PP material is configured, the diameter of which is 1.2 meters to 1.6 meters and the height is 0.7 meters to 0.9 meters; Microporous aeration pipes are laid at the bottom of the cultivation tank, and the microporous aeration pipes are connected to the oxygen output end of the oxygen generator; the oxygen generator generates oxygen with a purity of 90% to 95% through molecular sieve adsorption, and releases bubbles with a diameter of 0.1 mm to 0.5 mm through the microporous aeration pipes; the dissolved oxygen concentration in the cultivation tank is maintained at 9 mg / L to 11 mg / L, and the water temperature is maintained at 22℃ to 27℃; Stocking density should be 80,000 to 120,000 largemouth bass fry per cubic meter of water. The breeding and feeding stages include: feeding live Artemia for 7 to 10 days, feeding frozen Daphnia for 2 to 4 days, and acclimating to formulated feed for 7 to 10 days. During the cultivation and feeding stage, a compound microbial preparation is added to the cultivation tank daily at a rate of 0.1 g / m³. 3 Up to 0.3g / m 3 ; The aquaculture water is replaced daily by a circulating water system, replacing 15% to 25% of the water.

2. The method according to claim 1, characterized in that, The cultivation tanks are arranged in two parallel rows, with 5 to 12 cultivation tanks in each row; each cultivation tank is equipped with independent inlet and outlet pipes, microporous aeration pipes, and temperature control equipment; the circulating water system is connected to a microfilter, and the microfilter has a filtration accuracy of 20 micrometers to 50 micrometers.

3. The method according to claim 1, characterized in that, The acclimatization and compound feed stage adopts a gradual replacement method. Starting from the last day of feeding pure frozen water fleas, the frozen water fleas are gradually replaced with compound feed. The amount of frozen water fleas is reduced by 20% to 30% each day, and the amount of compound feed is increased by an equal amount. The cultivation period is 18 to 24 days.

4. The method according to claim 1, characterized in that, The oxygen generator performs the following process flow: The air compressor pressurizes ambient air to 0.55MPa to 0.65MPa, and outputs compressed air with a dew point ≤ -40℃; Compressed air is dried by a refrigerated dryer to remove liquid water before entering a dual-tower adsorption unit equipped with lithium-based zeolite molecular sieves. The dual-tower adsorption unit performs a pressure adsorption-depressurization desorption cycle: the adsorption tower adsorbs nitrogen for 25 to 30 seconds at 0.5 MPa to 0.6 MPa, and the desorption tower releases nitrogen at 0.15 MPa to 0.25 MPa. The pressure equalization operation is performed for 0.5 to 1.5 seconds between the two towers to ensure that the oxygen concentration fluctuation rate is ≤3%. After the produced oxygen is stabilized by a buffer tank, it passes through a series of activated carbon filters and polytetrafluoroethylene membrane filters to remove particles larger than 0.3 micrometers. The final output oxygen purity is 90% to 95%, and the flow rate is adjusted by a flow meter to an oxygen supply rate of 0.8 L / min to 1.5 L / min per cubic meter of cultivation water before being connected to a microporous aeration pipe.

5. The method according to claim 2, characterized in that, The independent inlet and outlet pipelines include a drain outlet at the bottom of the cultivation tank and an inlet at the top of the tank wall. The drain outlet is connected to an external circulating water system via a drain pipe. The microporous aeration pipe is laid in a U-shape straight pipe at the bottom of the cultivation tank and is connected to the filter output end of the oxygen generator via a pressure-resistant hose. The microporous aeration pipe is 1-2 cm away from the bottom wall of the cultivation tank. A dissolved oxygen sensor is installed in the middle of the cultivation tank. The temperature control equipment includes a heating cable located in the cultivation tank and a temperature sensor in the middle of the cultivation tank. The heating cable has a power of 300W to 400W per cubic meter of water. The inlet and outlet pipes, microporous aeration pipes, and temperature control equipment are linked and controlled by a PLC controller to perform the following operations: When the temperature sensor reading is below 22℃, start the heating cable until the water temperature reaches 25℃. When the dissolved oxygen sensor reading is below 9 mg / L for 2 minutes, increase the oxygen generator's output pressure by 0.056 MPa to 0.1 MPa; when the dissolved oxygen sensor reading is above 10.5 mg / L for 2 minutes, decrease the output pressure in increments of 0.02 MPa until the dissolved oxygen level drops below 10.5 mg / L. The drainage process is initiated daily at 18:00, with the drainage volume remaining constant at 15% to 25% of the culture tank volume.

6. The method according to claim 5, characterized in that, The heating cable is installed on the lower side wall of the cultivation tank and is covered by a removable stainless steel mesh cover with a mesh diameter of 0.8 mm to 1.0 mm. The mesh cover is embedded in the first branch pipe of the circulating water system, and the outlet of the first branch pipe is located at the bottom of the mesh cover. During the operation of the heating cable, the first branch pipe is started to supply water simultaneously, so that a directional water flow is formed inside the mesh cover. The bottom of the mesh cover is 5 cm to 10 cm away from the bottom of the tank. The surface temperature of the heating cable is monitored in real time by thermocouples and limited to 35°C to 38°C.

7. The method according to any one of claims 1-6, characterized in that, The compound microbial preparation contains 5-10 parts by weight of Lactobacillus plantarum, 5-10 parts of Lactobacillus acidophilus, 10-20 parts of Bacillus subtilis, 5-10 parts of Clostridium butyricum, and 5-10 parts of Rhodopseudomonas palustris. It is added before feeding at 8:00 a.m. every day and is used continuously until the end of the acclimatization and compound feed stage.

8. The method according to claim 7, characterized in that, The viable count of Lactobacillus plantarum was 5 × 10⁻⁶. 9 CFU / g, viable count of Lactobacillus acidophilus 5×10 9 CFU / g, viable count of Bacillus subtilis 1×10⁻⁶ 10 CFU / g, Clostridium butyricum viable count 5×10 9 CFU / g, viable count of Rhodopseudomonas palustris was 1×10⁻⁶. 8 CFU / g.

9. The method according to claim 8, characterized in that, LED light strips with wavelengths of 590 to 595 nanometers are installed on the top of the cultivation tank, with a light intensity of 300 to 500 lux; the light strips are turned on from 18:00 to 6:00 the next day.

10. The method according to claim 6, characterized in that, A microbial agent injection pipe is added at the bottom inlet of the mesh cover, which is connected to the composite microbial agent storage tank; the outlet of the second branch pipe of the circulating water system is close to the bottom wall of the cultivation tank and flows towards the drain outlet.

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