Shrimp fry breeding method for regulating water quality by microalgae and probiotics under specific illumination

Abstract

The application discloses a shrimp fry breeding method for regulating water quality by microalgae and probiotics under specific illumination, and technical solution points of the method comprise the following steps: step one, preparation of a breeding workshop; step two, microalgae-probiotic culture: selecting microalgae and probiotic species beneficial to shrimp fry breeding and culturing to obtain microalgae liquid and probiotic bacterial liquid; step three, preparation for feeding of shrimp fry; step four, feeding of shrimp fry larvae; step five, feeding of algae-probiotics; step six, illumination control for breeding; step seven, feeding of shrimp fry feed; step eight, monitoring and regulation of water quality; and step nine, evaluation and release of shrimp fry. The application precisely controls illumination, optimizes the growth environment of microalgae and probiotics, fully plays the synergistic effect of the microalgae and probiotics in water purification, nutrient supply and disease prevention and control, and thus improves the water quality of Litopenaeus vannamei breeding, improves the survival rate and health condition of shrimp fry, and lays a good foundation for large-scale and efficient breeding of Litopenaeus vannamei.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, specifically to a method for raising shrimp larvae by regulating water quality using microalgae and probiotics under specific lighting conditions. Background Technology

[0002] Litopenaeus vannamei is an important farmed shrimp species worldwide, and the water quality during its larval stage is crucial for the healthy growth, survival rate, and subsequent farming efficiency of the larvae. In traditional Litopenaeus vannamei larval rearing, water quality problems are a constant concern. As feeding increases, uneaten feed, feces, and other organic matter accumulate in the water, leading to elevated concentrations of harmful substances such as ammonia nitrogen and nitrite. This not only inhibits shrimp growth but also reduces their immunity and increases the risk of disease infection. Simultaneously, poor water quality easily leads to the overgrowth of harmful algae, such as cyanobacteria and dinoflagellates. The excessive proliferation of these algae disrupts the aquatic ecological balance, produces algal toxins, and seriously harms the shrimp's growth environment.

[0003] Current water quality control methods have many limitations. Physical methods, such as water exchange, can dilute harmful substances to some extent, but frequent water changes not only consume large amounts of water resources but also cause shrimp larvae to be caught in nets and suffer losses. Furthermore, they can easily disrupt the stability of the aquatic environment, leading to stress-induced losses in the shrimp larvae. Chemical methods, such as the use of chemical disinfectants and water conditioners, can improve water quality to some extent in the short term, but the inability to promptly remove harmful substances can potentially threaten the health of shrimp larvae, and long-term use can disrupt the ecological balance of the aquatic body. Existing biological control methods are often not effective enough to achieve comprehensive, stable, and lasting improvements in water quality.

[0004] Therefore, it is essential to improve existing methods for regulating water quality in aquaculture. The applicant has discovered in practice that microalgae and probiotics have significant potential in regulating water quality in aquaculture. Microalgae, through photosynthesis, can absorb nutrients such as nitrogen and phosphorus, as well as carbon dioxide, from the water, releasing oxygen and helping to maintain dissolved oxygen balance and reduce the concentration of harmful substances. Simultaneously, microalgae serve as a high-quality natural starter food for shrimp larvae, providing rich and comprehensive nutrition that significantly promotes their growth and development. Probiotics, on the other hand, can improve water quality and enhance shrimp immunity by decomposing organic matter and inhibiting the growth of harmful microorganisms. However, different types of microalgae and probiotics exhibit varying mechanisms and effects in water quality regulation, and their growth and function are influenced by various environmental factors, the most critical being light conditions. Therefore, developing a method for the synergistic regulation of Litopenaeus vannamei seedling water quality under specific light conditions using microalgae and probiotics has significant practical implications and application value. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for raising shrimp larvae by regulating water quality through microalgae and probiotics under specific lighting conditions. By precisely controlling the lighting, the growth environment of microalgae and probiotics is optimized, giving full play to their synergistic effects in water purification, nutrient supply, and disease control. This improves the water quality for raising Litopenaeus vannamei larvae, increases the survival rate and health status of the larvae, and lays a solid foundation for the large-scale and efficient farming of Litopenaeus vannamei larvae.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for raising shrimp larvae by regulating water quality with microalgae and probiotics under specific light conditions, comprising the following steps: Step 1: Construction of the Seedling Workshop: Construct a dedicated seedling workshop for Litopenaeus vannamei. A uniformly laid translucent panel and a shading device located on the upper part of the panel are fixedly connected to the roof of the seedling workshop. The workshop includes a shrimp larvae rearing area and a microalgae-probiotic rearing area compatible with the shrimp larvae rearing area. The shrimp larvae rearing area has several rearing ponds, each measuring 5m × 4m × 1.5m. Each pond is equipped with a compatible light sensor and a first LED light group. The first LED light group includes a compatible first blue light module, a first red light module, and a UVA module. The microalgae-probiotic production area has several microalgae culture tanks and several probiotic culture tanks. The microalgae-probiotic production area also includes temperature control equipment and a second LED light group compatible with the microalgae and probiotic culture tanks. The second LED light group includes a second red light module and a second blue light module that respectively produce red and blue light. Both the second and first LED light groups are waterproof. Step 2, Microalgae-Probiotic Cultivation: Select microalgae and probiotic species beneficial to shrimp larvae breeding and cultivate them. The microalgae species selected are Chlorella vulgaris, Chaetoceros muelleri, and Diatoms diatoms. The probiotic species selected are photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis. The selected Chlorella vulgaris, Chaetoceros muelleri, and Diatoms diatoms are respectively inoculated into microalgae cultivation tanks to obtain microalgae solution. The selected photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis are respectively inoculated into probiotic cultivation tanks to obtain probiotic solution. Step 3, Preparation for Seedling Stocking: Before raising shrimp seedlings, thoroughly clean and disinfect the seedling pond. First, use a high-pressure water gun to rinse the pond walls and bottom to remove debris and dirt. Then, soak the pond in a 20-30 ppm available chlorine bleaching powder solution for 2-3 hours. After that, rinse the seedling pond with clean water. Finally, inject an appropriate amount of shrimp seedling raising water into the seedling pond. The initial water depth in the seedling raising water should be controlled at 0.7-0.8 m, the pH value should be set at 8.2, and the water temperature should be controlled at 30℃. Step 4: Release shrimp larvae: Evenly release an appropriate number of shrimp larvae into the nursery pond. The released shrimp larvae should be in the nauplius stage. Step 5: Algae-Probiotic Addition: After introducing shrimp larvae, add algae solution of *Gynostemma pentaphyllum*. When the shrimp larvae develop into zoea larvae, add algae solution of *Chaetoceros muelleri*. Then, when the shrimp larvae develop into mysid larvae, add algae solution of diatoms. The dosage of each algae solution is 50L, and the algae solution should be evenly sprinkled in the nursery pond. At the same time, after each type of microalgae solution is added, photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis bacterial solutions are added in sequence. The dosage of each bacterial solution is 0.5L, and the bacterial solutions should be diluted with an appropriate amount of water before being evenly sprinkled throughout the pond. Step Six: Seedling Light Control: For the first 3 days after the introduction of microalgae and probiotics, the light intensity in the seedling pond should be controlled at 3000-5000 lx, with a light cycle of 14 hours of light and 10 hours of darkness. After 3 days, adjust the light intensity and light cycle appropriately based on the growth of microalgae and the transparency of the water. If the microalgae in the seedling pond grow too vigorously and the water transparency decreases, reduce the light intensity to 3000-4000 lx and shorten the light time, i.e., set the light cycle to 12 hours of light and 12 hours of darkness. If the microalgae in the seedling pond grow slowly, increase the light intensity to 6000-8000 lx and extend the light time, i.e., set the light cycle to 16 hours of light and 8 hours of darkness. Step 7: Feeding Shrimp Larvae: When shrimp larvae develop into zoea larvae, feed them high-grade shrimp chips and No. 0 cypermethrin, and wash them with a 250-160 mesh net, feeding 1-2g per cubic meter of water; when shrimp larvae develop into zoea larvae stage II, feed them brine shrimp, with a feeding amount of 2-4 per shrimp larvae; when shrimp larvae develop into mysid larvae, feed them No. 2 shrimp chips and No. 0 cypermethrin, and wash them with a 120-100 mesh net, feeding 2-3g per cubic meter of water, while also feeding them brine shrimp, with a feeding amount of 4-7 per shrimp larvae; when shrimp larvae develop into roe shrimp larvae, feed them No. 5 shrimp chips and No. 1 cypermethrin, and wash them with an 80-40 mesh net, feeding 3-5g per cubic meter of water, while also feeding them live brine shrimp, with a feeding amount of 8-20 per shrimp larvae. Step 8: Water quality monitoring and control: Monitor various water quality indicators in the seedling pond regularly every day, and make corresponding adjustments based on the monitored water quality indicators; Step 9: Shrimp larvae evaluation and release: The survival rate, body length, and weight growth indicators of shrimp larvae are recorded and collected using a sampling statistical method. Based on the survival rate, body length, and weight growth indicators, it is determined whether the shrimp larvae meet the criteria for release. Those that meet the criteria are released, while those that do not meet the criteria continue to be cultivated until they reach the criteria for release. In step six, from 05:00 to 07:00 daily, the seedling pond is irradiated with ultraviolet light generated by the UVA module in the first LED light group; from 08:00 to 18:00 daily, the light in the seedling pond is mainly natural light coming in from the roof, and the light intensity in the seedling workshop is dynamically adjusted by the light sensor in conjunction with the shading net. If the light intensity is weak, such as on cloudy or rainy days, the seedling pond is supplemented with natural light by the first LED light group to achieve a suitable light intensity; from 19:00 to 22:00 daily, the seedling pond is supplemented with red light generated by the red light module in the LED light group.

[0007] By adopting the above technical solutions, controlling light conditions, optimizing the growth environment of shrimp larvae, microalgae, and probiotics, and giving full play to the synergistic effects of microalgae and probiotics in water purification, nutrient supply, and disease control, and by regularly monitoring various water quality indicators in the breeding pond, the water quality of shrimp larvae breeding can be improved, thereby increasing the survival rate and health status of shrimp larvae and laying a good foundation for the large-scale and efficient farming of Litopenaeus vannamei.

[0008] The present invention is further configured such that: the light-transmitting plate is a polycarbonate hollow plate, the surface of the light-transmitting plate has a UV coating and its light transmittance is 70%, and a prism refractive film is attached to the surface of the light-transmitting plate; the sunshade device adopts an electric folding PE sunshade net, and the light transmittance of the sunshade net is set to 30-80%.

[0009] By adopting the above technical solution, the light-transmitting panel is set as a polycarbonate hollow panel, and a prism refractive film is attached to the surface, so that the light entering the seedling workshop from the roof is scattered, thus making the light in the seedling workshop more uniform. The shade net can automatically adjust the opening and closing degree according to the outdoor light intensity.

[0010] The present invention is further configured such that: the seedling pool is made of fiberglass and has a rectangular structure; a drain outlet is provided at one corner of the bottom of the seedling pool; the bottom of the seedling pool is inclined and inclined towards the drain outlet; the corners of the seedling pool are all rounded; each seedling pool is equipped with a matching light sensor and a first LED light group; the first LED light group includes a matching first blue light module, a first red light module and a UVA module.

[0011] By adopting the above technical solutions, the drainage outlets at the bottom of the seedling pond and their sloping design facilitate the discharge of waste and prevent accumulation at the bottom of the pond. The corners of the seedling pond are all rounded to avoid damage caused by the aggregation of shrimp larvae. The light sensor is used to detect the light intensity in the seedling pond and works in conjunction with the shade net to adjust its opening and closing size, thereby controlling the light intensity in the seedling workshop. The first LED light group is used to supplement light and illuminate the seedling pond to ensure that it is under suitable light conditions for shrimp larvae cultivation.

[0012] The present invention is further configured such that the culture methods for each microalgae in step two are as follows: 1) When culturing *Gynostemma pentaphyllum*, use f / 2 medium prepared with natural seawater. Pour the boiled and cooled medium into the microalgae culture tank, disinfect with chlorine-containing disinfectant tablets, and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then, inoculate *Gynostemma pentaphyllum* in the logarithmic growth phase at an inoculation density of 1×10⁴-3×10⁴ cells / mL. Maintain the culture temperature at 18-25℃ using the temperature control device, and control the light intensity at 5000-7000 lx. Irradiate with blue light at 450nm and red light at 660nm using a second LED light group. The light cycle is set to 16 hours of light and 8 hours of darkness. During the culture process, oxygen is supplied by a blower and air stones to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reaches 1×10⁶-2×10⁶ cells / mL, a *Gynostemma pentaphyllum* solution is obtained that can be used for subsequent seedling pond placement. 2) When culturing Chaetoceros muelleri, f / 2 medium is used, prepared with natural seawater. The boiled and cooled medium is poured into the microalgae culture tank, disinfected with chlorine-containing disinfectant tablets, and then neutralized with sodium thiosulfate. Subsequently, Chaetoceros muelleri algae in the logarithmic growth phase are inoculated at a density of 2×10⁴-4×10⁴ cells / mL. The culture temperature is maintained at 18-25℃ using the temperature control device, and the light intensity is controlled at 3000-5000 lx. The second LED lamp group generates blue light with a spectral wavelength of 470nm for irradiation. The light cycle is set to 12h light and 12h dark. During the culture process, a blower and air stones are used for oxygenation to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reaches 2×10⁶-3×10⁶ cells / mL, it can be used for seedling in the seedling pond. 3) When culturing small diatoms, a special diatom culture medium is used, prepared with natural seawater. The boiled and cooled culture medium is poured into the microalgae culture tank, disinfected with chlorine-containing disinfectant tablets, and then neutralized with sodium thiosulfate. Subsequently, small diatoms in the logarithmic growth phase are inoculated at a density of 1.5×10⁴-3.5×10⁴ cells / mL. The culture temperature is maintained at 20-25℃ using the temperature control device, and the light intensity is controlled at 5000-8000 lx. Irradiation is provided by a second LED light group that generates blue light at 450nm and red light at 630nm. The light cycle is set to 14 hours of light and 10 hours of darkness. During the culture process, a blower and air stones are used for oxygenation to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reaches 1.5×10⁶-2.5×10⁶ cells / mL, it can be used for seedling cultivation.

[0013] By adopting the above technical solutions, *Gynostemma pentaphyllum* cells are rich in protein, polysaccharides, and various unsaturated fatty acids. They can not only efficiently absorb nutrients such as nitrogen and phosphorus in the water and improve water quality, but also serve as a high-quality first feed for shrimp larvae. Their slow swimming speed makes it easy for shrimp larvae to catch prey. *Chaetoceros muelleri* grows rapidly and has a strong tolerance and conversion ability to high concentrations of ammonia nitrogen, which can effectively reduce the ammonia nitrogen content in the water. The horns on its cell surface can also increase water turbulence, which is conducive to material exchange. It often exists in the form of single cells or groups of a few cells, which is suitable for shrimp larvae to feed on. In addition, *Microdiatoms* have strong adaptability and can grow well under different salinity and temperature conditions. They can utilize a variety of nutrients in the water. Their cell walls are rich in silica, which helps the development of shrimp larvae's skeleton. Moreover, their cell size is moderate, making them one of the favorite foods of shrimp larvae.

[0014] The present invention is further configured such that the probiotic culture methods in step two are as follows: 1) When culturing photosynthetic bacteria, use a special culture medium for photosynthetic bacteria. Dissolve one packet of culture medium and pour it into the probiotic culture tank, then fill it with sand-filtered seawater. Disinfect the tank with chlorine-containing disinfectant tablets and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then, inoculate the photosynthetic bacteria inoculum at a volume ratio of 5-10%. Maintain the culture temperature at 25-35℃ using the temperature control device, and control the light intensity at 10000-15000 lx. Irradiate with blue light at 470nm and red light at 800nm. Set the light cycle to 14 hours of light and 10 hours of darkness. Stir regularly during the culture process to ensure full contact between the bacteria and the culture medium. When the OD660 value of the probiotic solution reaches 0.8-1.2, it indicates that the photosynthetic bacteria are growing well and can be used in the seedling pond. 2) When culturing Bacillus subtilis, brown sugar is used for expansion and fermentation. 2 catties of brown sugar is dissolved and poured into the probiotic culture tank, then filled with sand-filtered seawater. The tank is disinfected with chlorine-containing disinfectant tablets, and the residual chlorine is neutralized with sodium thiosulfate after disinfection. Then, Bacillus subtilis inoculum is introduced at a volume ratio of 3-5%. The tank opening is sealed with plastic wrap, and air stones are placed inside for aeration. The temperature is maintained at 25-35℃ using the temperature control equipment. Fermentation lasts for 24-48 hours. When the probiotic concentration reaches 1×10⁹-2×10⁹ CFU / mL, it can be used in the seedling pond. 3) When culturing Enterococcus faecalis, use brown sugar for expansion and fermentation. Dissolve 2 catties of brown sugar and pour it into the probiotic culture tank, then fill it with sand-filtered seawater. Disinfect with chlorine-containing disinfectant tablets, and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then inoculate with Enterococcus faecalis inoculum at a volume ratio of 4-6%. Stir thoroughly and seal the tank opening with plastic wrap. Maintain the temperature at 25-35℃ using the temperature control equipment. Cultivate under anaerobic conditions for 24-48 hours. When the probiotic concentration reaches 1×10⁹-1.5×10⁹ CFU / mL, it can be used for distribution in the seedling pond.

[0015] By adopting the above technical solutions, photosynthetic bacteria can grow and reproduce using small-molecule organic matter, hydrogen sulfide, ammonia nitrogen, etc. in the water as nutrients under anaerobic light or aerobic darkness conditions, thereby reducing the concentration of harmful substances in the water. Simultaneously, their cells are rich in nutrients such as protein and vitamins, which can serve as indirect feed for shrimp larvae. Bacillus subtilis can produce various enzymes, such as proteases, amylases, and lipases. These enzymes can decompose large-molecule organic matter in the water, converting it into smaller molecules that are easily utilized by microalgae and other microorganisms, thus purifying the water. Furthermore, it produces antibacterial substances during its growth, which can inhibit the growth of harmful bacteria. Enterococcus faecalis can regulate the microecological balance of the water and enhance the immunity of shrimp. During its metabolism, it can produce organic acids such as lactic acid, lowering the pH value of the water and inhibiting the growth of harmful microorganisms. It can also synthesize various vitamins and amino acids, providing nutrition for shrimp.

[0016] The invention is further configured as follows: In step three, seawater that has undergone sedimentation and sand filtration is injected into a water tank used for temporary storage and transfer. The salinity of the seawater is set to 25-35‰. Then, 20ppm bleaching powder is used to disinfect the seawater in the treatment tank for 2 hours, and an appropriate amount of sodium thiosulfate is sprinkled to neutralize the residual chlorine. Then, 10g / m3 of disodium EDTA is sprinkled. Finally, after aeration and sedimentation, the water for shrimp larvae rearing is obtained.

[0017] By adopting the above technical solutions, the water used for shrimp larvae cultivation is made more suitable for shrimp larvae cultivation.

[0018] The present invention is further configured such that: the water quality indicators include water temperature, salinity, pH value, dissolved oxygen, ammonia nitrogen content and nitrite content; the water temperature, salinity, pH value and dissolved oxygen are measured using a WTW3410 multi-parameter water quality analyzer; the ammonia nitrogen content is determined using Nessler's reagent spectrophotometry; and the nitrite content is determined using naphthylethylenediamine hydrochloride spectrophotometry.

[0019] By adopting the above technical solution, the water temperature, salinity, pH value, dissolved oxygen, ammonia nitrogen content and nitrite content in the shrimp larvae cultivation water are measured, which facilitates the adjustment of the water quality in the shrimp larvae cultivation water to promote the growth and development of the shrimp larvae.

[0020] The invention is further configured as follows: In step eight, when the water temperature is below 28°C, the water temperature is appropriately increased using heating equipment; when the salinity is below 22‰ before the shrimp larvae develop into mysid larvae, the salinity is adjusted by adding sea salt crystals; when the pH value is above 8.6, an appropriate amount of citric acid is added for adjustment; when the pH value is below 7.8, quicklime is used for adjustment; when the dissolved oxygen content is below 5 mg / L, the oxygenation rate is increased in a timely manner; when the ammonia nitrogen content exceeds 0.2 mg / L or the nitrite content exceeds 0.1 mg / L after the shrimp larvae develop into mysid larvae, the water should be changed appropriately, with each water change not exceeding 20% ​​of the total water volume.

[0021] By adopting the above technical solutions, the water temperature, pH value, dissolved oxygen content, ammonia nitrogen content, and nitrite content are adjusted to improve the water quality for shrimp larvae cultivation, thus facilitating the growth and development of shrimp larvae.

[0022] The present invention is further configured such that: in step eight, it is also necessary to regularly observe the growth status and algal composition of microalgae in the nursery pond, and after the shrimp larvae develop into fry, algal solution and bacterial solution are added once a week, with the addition amount being 50L of each algal solution and 1L of each bacterial solution.

[0023] By adopting the above technical solution, the algal solution and probiotic solution are replenished regularly to prevent the natural consumption of algal and probiotic solutions during shrimp larvae cultivation and to ensure that the concentration of algal and probiotic solutions in the nursery pond is maintained at a level conducive to shrimp larvae development.

[0024] In summary, the present invention has the following beneficial effects: 1. Significant water purification effect: Through the synergistic effect of microalgae and probiotics under specific light conditions, it can effectively remove harmful substances such as ammonia nitrogen and nitrite from the water. Microalgae absorb nutrients such as nitrogen and phosphorus through photosynthesis and convert them into their own biomass, thereby reducing the concentration of nutrients in the water. Probiotics further purify the water by decomposing organic matter and participating in nitrogen cycling. 2. Promotes shrimp larvae growth and development: As high-quality natural feed, *Chaetoceros muelleri*, *Chaetoceros muelleri*, and small diatoms provide shrimp larvae with abundant protein, polysaccharides, unsaturated fatty acids, and vitamins, meeting their nutritional needs during growth. Simultaneously, a suitable water environment facilitates digestion, absorption, and metabolism, promoting growth rate and health. Short-term UVA irradiation can increase weight gain and feed conversion rate. Compared to traditional breeding methods, shrimp larvae cultivated using this invention show significant improvements in body length and weight growth indicators, increasing the survival rate by 10-20%. 3. Enhance shrimp immunity: Probiotics such as photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis form beneficial microbial communities in the water, inhibiting the growth and reproduction of harmful microorganisms, especially Vibrio and fungi, reducing the risk of shrimp larvae getting "dirty" and contracting diseases. In addition, probiotics can also regulate the intestinal microecological balance of shrimp, enhance the immunity and disease resistance of shrimp larvae, thereby effectively reducing the incidence of disease in shrimp larvae during the breeding process and improving the quality and stability of Litopenaeus vannamei breeding. 4. Ecological, Environmentally Friendly, and Sustainable: This invention utilizes biological methods such as microalgae and probiotics for water quality control, avoiding the extensive use of chemical agents and reducing potential harm to the aquatic environment and shrimp larvae. This aligns with the development philosophy of green, environmentally friendly, and sustainable aquaculture. Simultaneously, by precisely controlling environmental conditions such as light, the growth and function of microalgae and probiotics are optimized, improving the utilization efficiency of biological resources and significantly extending the effective action time of algae and bacteria. This avoids frequent addition of algae and bacteria, reducing workload. Spectral matching technology can increase microalgae biomass, enhancing shrimp larvae self-sufficiency in feed; reducing the cost of formulated feed; and solving pain points in larvae breeding such as algae bloom collapse on rainy days. This improves larvae quality and breeding stability, resulting in significant economic and social benefits. Attached Figure Description

[0025] Figure 1 This is a principle block diagram illustrating the implementation steps of the present invention. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] This embodiment discloses a method for raising shrimp larvae by regulating water quality using microalgae and probiotics under specific lighting conditions, such as... Figure 1 As shown, it includes the following steps: Step 1: Construction of the Seedling Workshop: Construct a dedicated seedling workshop for Litopenaeus vannamei shrimp. The roof of the seedling workshop will be fixed with evenly laid translucent panels and shading devices located on the upper side of the panels. The workshop will include a shrimp larvae rearing area and a microalgae-probiotics rearing area. The shrimp larvae rearing area will have several dedicated seedling ponds for Litopenaeus vannamei shrimp larvae rearing. The microalgae-probiotics rearing area will have several microalgae culture tanks and several probiotic culture tanks. These tanks will be used to expand the cultivation of algae and probiotics, respectively. Both the microalgae and probiotic culture tanks will be 50L round PE containers. The seedling workshop has a construction area of ​​50m × 30m and a floor height of 6m. The light-transmitting panels are made of polycarbonate hollow panels with a 5mm thick UV coating and a light transmittance of 70%. A prism refractive film is also attached to the surface of the panels to scatter the light entering the workshop from the roof, resulting in more uniform lighting. The shading device uses an electrically folding PE shade net with a light transmittance of 30-80%, and the net can automatically adjust its opening and closing degree according to the outdoor light intensity. The seedling rearing ponds are made of fiberglass and have a rectangular structure, with dimensions of 5m × 4m × 1.5m. A drain outlet is located at one corner of the pond bottom, which is angled towards the drain outlet. This angled design facilitates waste removal and prevents accumulation at the bottom. The corners of the ponds are rounded to prevent shrimp larvae from gathering and getting injured. Each seedling pond is equipped with a matching light sensor and a first LED light group. The light sensor detects the light intensity within the pond and works in conjunction with the shade net to adjust its opening and closing, thus controlling the light intensity in the rearing area. The first LED light group includes a matching first blue light module, a first red light module, and a UVA module. These modules generate blue light, red light, and ultraviolet light respectively to suit the light requirements of the seedling pond. The first LED light group is used for supplemental lighting and illuminating the seedling pond to ensure suitable lighting conditions for shrimp larvae cultivation. The microalgae-probiotic production area is also equipped with temperature control equipment and a second LED light group that are compatible with the microalgae culture tank and the probiotic culture tank. The second LED light group uses a special algae spectrum lamp and includes a second red light module and a second blue light module that produce red light and blue light respectively. Both the first LED light group and the second LED light group are waterproof. Step 2, Microalgae-Probiotic Cultivation: Select microalgae and probiotic species beneficial to shrimp larvae breeding and cultivate them. The microalgae species selected are Chlorella vulgaris, Chaetoceros muelleri, and Diatoms diatoms. The probiotic species selected are photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis. The selected Chlorella vulgaris, Chaetoceros muelleri, and Diatoms diatoms are inoculated into the microalgae cultivation tank for cultivation, and the selected photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis are inoculated into the probiotic cultivation tank for cultivation. For the cultivation of *Chlorophytum comosum*, an f / 2 medium prepared with natural seawater was used. The boiled and cooled medium was poured into the microalgae culture tank, and sterilized with chlorine-containing disinfectant tablets. After sterilization, residual chlorine was neutralized with sodium thiosulfate. Subsequently, *Chlorophytum comosum* algae in the logarithmic growth phase were inoculated at a density of 1×10⁻⁶. 4 -3×10 4The algal cell density was maintained at 18-25℃ using a temperature control device, and the light intensity was controlled at 5000-7000 lx. Irradiation was provided by a second LED lamp group, which generated blue light with a wavelength of 450nm and red light with a wavelength of 660nm. The light cycle was set to 16 hours of light and 8 hours of darkness. During the cultivation process, a blower and air stones were used for oxygenation to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reached 1×10⁻⁶ cells / mL, the culture was completed. 6 -2×10 6 When the concentration of *Clerodendrum trichotomum* is reached at 1000 / mL, a solution of *Clerodendrum trichotomum* that can be used for subsequent seedling pond placement is obtained. For the cultivation of Chaetoceros muelleri, an f / 2 medium prepared with natural seawater was used. The boiled and cooled medium was poured into the microalgae culture tank, and the tank was disinfected with chlorine-containing disinfectant tablets. After disinfection, sodium thiosulfate was used to neutralize the residual chlorine. Subsequently, Chaetoceros muelleri algae in the logarithmic growth phase were inoculated at a density of 2 × 10⁻⁶. 4 -4×10 4 The algal cell density was maintained at 18-25℃ using a temperature control device, and the light intensity was controlled at 3000-5000 lx. Irradiation was provided by a second LED lamp group generating blue light with a wavelength of 470 nm. The light cycle was set to 12 hours of light followed by 12 hours of darkness. During cultivation, aeration was achieved using blowers and air stones to promote gas exchange and uniform nutrient distribution. The cultivation was continued until the algal cell density of the microalgae solution reached 2 × 10⁻⁶ cells / mL. 6 -3×10 6 When the number of cells / mL reaches a certain level, it can be used for subsequent seedling placement in the nursery pond; For the cultivation of diatoms, a special diatom culture medium prepared with natural seawater was used. The boiled and cooled culture medium was poured into the microalgae cultivation tank, and sterilized with chlorine-containing disinfectant tablets. After sterilization, residual chlorine was neutralized with sodium thiosulfate. Then, diatoms in their logarithmic growth phase were inoculated at a density of 1.5 × 10⁻⁶. 4 -3.5×10 4 The algal cell density was maintained at 20-25℃ using a temperature control device, and the light intensity was controlled at 5000-8000 lx. Irradiation was provided by a second LED light group, generating blue light at 450nm and red light at 630nm. The light cycle was set to 14 hours of light and 10 hours of darkness. During cultivation, a blower and air stones were used for oxygenation to promote gas exchange and uniform nutrient distribution. The cultivation was continued until the algal cell density reached 1.5 × 10⁻⁶ cells / mL. 6 -2.5×10 6 When the number of cells / mL reaches a certain level, it can be used for subsequent seedling placement in the nursery pond; When culturing photosynthetic bacteria, use a special culture medium for photosynthetic bacteria. Dissolve one packet of the culture medium and pour it into the probiotic culture tank, then fill it with sand-filtered seawater. Disinfect the tank with chlorine-containing disinfectant tablets and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then, inoculate the photosynthetic bacteria inoculum at a volume ratio of 5-10%. Maintain the culture temperature at 25-35℃ using a temperature control device, and control the light intensity at 10000-15000 lx. Irradiate with blue light at 470nm and red light at 800nm. Set the light cycle to 14 hours of light and 10 hours of darkness. Stir regularly during the culture process to ensure full contact between the bacteria and the culture medium. When the OD660 value of the probiotic solution reaches 0.8-1.2, it indicates that the photosynthetic bacteria are growing well and can be used for subsequent seedling pond release. When culturing Bacillus subtilis, brown sugar is used for expansion and fermentation. Two kilograms of brown sugar are dissolved and poured into a probiotic culture tank, which is then filled with sand-filtered seawater. The tank is disinfected with chlorine-containing disinfectant tablets, and residual chlorine is neutralized with sodium thiosulfate afterward. Bacillus subtilis inoculum is then inoculated at a volume ratio of 3-5%. The tank opening is sealed with plastic wrap, and an air stone is placed inside for aeration. The temperature is maintained at 25-35℃ using a temperature control device, and fermentation is carried out for 24-48 hours. Fermentation continues until the probiotic concentration reaches 1×10⁻⁶. 9 -2×10 9 When the concentration is CFU / mL, it can be used for subsequent seedling bed placement; For the cultivation of Enterococcus faecalis, brown sugar is used for expansion and fermentation. Two kilograms of brown sugar are dissolved and poured into a probiotic culture tank, which is then filled with sand-filtered seawater. The tank is disinfected using chlorine-containing disinfectant tablets, and residual chlorine is neutralized with sodium thiosulfate afterward. Enterococcus faecalis inoculum is then inoculated at a volume ratio of 4-6%. The mixture is thoroughly stirred, and the tank is sealed with plastic wrap. The temperature is maintained at 25-35°C using a temperature control device. The tank is cultured under anaerobic conditions for 24-48 hours. The culture is complete when the probiotic concentration reaches 1×10⁻⁶. 9 -1.5×10 9 When the concentration is CFU / mL, it can be used for subsequent seedling bed placement; Microalgae can absorb nutrients such as nitrogen and phosphorus, as well as carbon dioxide, from water through photosynthesis, thereby releasing oxygen. This helps maintain dissolved oxygen balance and reduce the concentration of harmful substances in the water. Microalgae are also a high-quality natural first food for shrimp larvae, providing rich and comprehensive nutrition that significantly promotes their growth and development. *Gynostemma pentaphyllum* cells are rich in protein, polysaccharides, and various unsaturated fatty acids. They not only efficiently absorb nutrients such as nitrogen and phosphorus from the water, improving water quality, but also serve as a high-quality first food for shrimp larvae. Their slow swimming speed facilitates predation by the larvae. *M. moschata*... Chaetoceros grows rapidly and has a strong tolerance and conversion ability to high concentrations of ammonia nitrogen, which can effectively reduce the ammonia nitrogen content in the water. The horns on the surface of its cells can also increase the turbulence of the water, which is conducive to the exchange of substances. It often exists in the form of single cells or groups of a few cells, which is suitable for shrimp larvae to feed on. In addition, small diatoms have strong adaptability and can grow well under different salinity and temperature conditions. They can utilize a variety of nutrients in the water. Their cell walls are rich in silica, which helps the development of the shrimp larvae's skeleton. Moreover, their cells are of moderate size, making them one of the favorite foods of shrimp larvae. Probiotics can improve water quality and enhance shrimp immunity by decomposing organic matter and inhibiting the growth of harmful microorganisms. Photosynthetic bacteria can grow and reproduce using small-molecule organic matter, hydrogen sulfide, and ammonia nitrogen in the water as nutrients under anaerobic light or aerobic darkness, thereby reducing the concentration of harmful substances in the water. Their cells are also rich in protein, vitamins, and other nutrients, serving as indirect feed for shrimp larvae. Bacillus subtilis can produce various enzymes, such as proteases, amylases, and lipases. These enzymes can decompose large-molecule organic matter in the water, converting it into smaller molecules that are easily utilized by microalgae and other microorganisms, thus purifying the water. Furthermore, it produces antibacterial substances during its growth, inhibiting the growth of harmful bacteria. Enterococcus faecalis can regulate the microecological balance of the water and enhance shrimp immunity. During its metabolism, it produces organic acids such as lactic acid, lowering the pH value of the water and inhibiting the growth of harmful microorganisms. It can also synthesize various vitamins and amino acids, providing nutrition for shrimp. Step 3, Preparation for Seedling Stocking: Before raising shrimp seedlings, thoroughly clean and disinfect the seedling pond. First, use a high-pressure water gun to rinse the pond walls and bottom to remove debris and dirt. Then, soak the pond in a 20-30 ppm available chlorine bleaching powder solution for 2-3 hours. After that, rinse the seedling pond with clean water. Finally, inject an appropriate amount of shrimp seedling raising water into the seedling pond. The initial water depth in the seedling raising water should be controlled at 0.7-0.8 m, the pH value should be set at 8.2, and the water temperature should be controlled at 30℃. The water used for shrimp larvae rearing involves injecting seawater that has undergone sedimentation and sand filtration into a temporary storage tank. The salinity of the seawater is set to 25-35‰. The seawater in the treatment tank is then disinfected with 20ppm bleaching powder for 2 hours, and an appropriate amount of sodium thiosulfate is added to neutralize residual chlorine. Finally, 10g / m³ of bleaching powder is added. 3 The EDTA disodium salt was finally precipitated by gas cessation to obtain shrimp larvae breeding water that could be pumped into the breeding pond. Step 4: Release shrimp larvae: Evenly release an appropriate number of shrimp larvae into the nursery pond. The released shrimp larvae should be in the nauplius stage. Step 5: Algae-Probiotic Addition: After introducing shrimp larvae, add algae solution of *Gynostemma pentaphyllum*. When the shrimp larvae develop into zoea larvae, add algae solution of *Chaetoceros muelleri*. Then, when the shrimp larvae develop into mysid larvae, add algae solution of diatoms. The dosage of each algae solution is 50L, and the algae solution should be evenly sprinkled in the nursery pond. At the same time, after each type of microalgae solution is added, photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis bacterial solutions are added in sequence. The dosage of each bacterial solution is 0.5L, and the bacterial solutions should be diluted with an appropriate amount of water before being evenly sprinkled throughout the pond. Step Six: Seedling Light Control: For the first 3 days after the introduction of microalgae and probiotics, the light intensity in the seedling pond should be controlled at 3000-5000 lx, with a light cycle of 14 hours of light and 10 hours of darkness. After 3 days, adjust the light intensity and light cycle appropriately based on the growth of microalgae and the transparency of the water. If the microalgae in the seedling pond grow too vigorously and the water transparency decreases, reduce the light intensity to 3000-4000 lx and shorten the light time, i.e., set the light cycle to 12 hours of light and 12 hours of darkness. If the microalgae in the seedling pond grow slowly, increase the light intensity to 6000-8000 lx and extend the light time, i.e., set the light cycle to 16 hours of light and 8 hours of darkness. Meanwhile, from 05:00 to 07:00 daily, ultraviolet light generated by the UVA module in the first LED light group is used to irradiate the seedling pond to promote the feeding activity of shrimp larvae, enhance their immunity, and inhibit the reproduction of Vibrio in the seedling pond. From 08:00 to 18:00 daily, the light in the seedling pond is mainly natural light coming in from the roof. The light intensity in the seedling pond is monitored by a light sensor and dynamically adjusted in conjunction with the shade net. If the light intensity is weak, such as on cloudy or rainy days, the seedling pond is supplemented with natural light by the first LED light group to achieve the appropriate light intensity. From 19:00 to 22:00 daily, red light generated by the red light module in the LED light group is used to supplement the light in the seedling pond to stimulate the microalgae in the seedling pond to divide and develop at night. The light control conditions for shrimp larvae, microalgae, and probiotics are as follows:

[0028] Table 1 Lighting Control Status Step 7: Feeding Shrimp Larvae: When shrimp larvae develop into zoea larvae, feed them high-grade shrimp chips and No. 0 cypermethrin, and wash them with a 250-160 mesh net, feeding 1-2g per cubic meter of water; when shrimp larvae develop into zoea larvae stage II, feed them brine shrimp, with a feeding amount of 2-4 per shrimp larvae; when shrimp larvae develop into mysid larvae, feed them No. 2 shrimp chips and No. 0 cypermethrin, and wash them with a 120-100 mesh net, feeding 2-3g per cubic meter of water, while also feeding them brine shrimp, with a feeding amount of 4-7 per shrimp larvae; when shrimp larvae develop into roe shrimp larvae, feed them No. 5 shrimp chips and No. 1 cypermethrin, and wash them with an 80-40 mesh net, feeding 3-5g per cubic meter of water, while also feeding them live brine shrimp, with a feeding amount of 8-20 per shrimp larvae. Step 8: Water quality monitoring and control: Monitor various water quality indicators in the seedling pond regularly every day, and make corresponding adjustments based on the monitored water quality indicators; The water quality indicators include water temperature, salinity, pH value, dissolved oxygen, ammonia nitrogen content, and nitrite content. The water temperature, salinity, pH value, and dissolved oxygen are measured using a WTW3410 multi-parameter water quality analyzer. The ammonia nitrogen content is determined by Nessler's reagent spectrophotometry, and the nitrite content is determined by the naphthylethylenediamine hydrochloride spectrophotometry. When the water temperature is below 28℃, raise the water temperature appropriately using heating equipment; when the salinity is below 22‰ before the shrimp larvae develop into mysid larvae, adjust the salinity by adding sea salt crystals; when the pH value is above 8.6, adjust it by adding an appropriate amount of citric acid; when the pH value is below 7.8, adjust it by using quicklime; when the dissolved oxygen content is below 5mg / L, increase the oxygenation rate in time; when the ammonia nitrogen content exceeds 0.2mg / L or the nitrite content exceeds 0.1mg / L after the shrimp larvae develop into mysid larvae, change the water appropriately, with each water change not exceeding 20% ​​of the total water volume; at the same time, regularly observe the growth status and algal community composition of microalgae, and supplement algae solution and bacterial solution once a week after the shrimp larvae develop into mysid larvae, with a supplementation amount of 50L of each algae solution and 1L of each bacterial solution.

[0029] Step 9: Shrimp larvae evaluation and release: The survival rate, body length, and weight growth indicators of the shrimp larvae are recorded and collected using a sampling statistical method. Based on the survival rate, body length, and weight growth indicators, it is determined whether the shrimp larvae meet the criteria for release. Those that meet the criteria are released, while those that do not meet the criteria continue to be cultivated until they reach the criteria for release.

[0030] The applicant conducted a comparative experiment using the above method, and the results are as follows: S1. Microalgae-probiotic culture: Cultivate Chrysophyta var. muscheri, Chaetoceros muelleri, diatoms, photosynthetic bacteria, Bacillus subtilis and Enterococcus faecalis according to the above method.

[0031] S2. Seedling bed preparation: Select three seedling beds of the same size and label them as Seedling Bed No. 1, Seedling Bed No. 2 and Seedling Bed No. 3 respectively. Prepare the three seedling beds for seedling planting according to the method described above.

[0032] S3. Stocking shrimp larvae: Stock the same number and size of Litopenaeus vannamei shrimp larvae into the three nursery ponds.

[0033] S4. Microalgae and Probiotics Addition and Light Control: In Seedling Pond No. 1, microalgae solution and probiotic solution are added sequentially according to the time and density specified in the above method, and the light intensity and light cycle are strictly controlled; In Seedling Pond No. 2, microalgae are added only according to the conventional method, without adding probiotics, and natural light is used; In Seedling Pond No. 3, no microalgae are added, only probiotics are added according to the conventional dosage, and natural light is also used.

[0034] S5. Feeding: Place the same amount and size of feed in each of the three nursery ponds.

[0035] S6. Water quality monitoring and control: Monitor the water quality of the three seedling ponds daily. Water quality indicators include temperature, salinity, pH value, dissolved oxygen, ammonia nitrogen content, and nitrite content. Based on the monitoring results, control the water quality of seedling pond No. 1 according to the control measures in the above method. Use traditional water quality control methods, such as water exchange and use of chemical water quality improvers, for seedling ponds No. 2 and No. 3.

[0036] S7. Shrimp Larvae Cultivation and Effect Evaluation: A 20-day larval cultivation experiment was conducted. After the experiment, the survival rate, body length, and weight growth indicators of the shrimp larvae were recorded, and the content of harmful substances in the water was measured. The results are shown in the table below:

[0037] Table 2 Comparison of Shrimp Larvae Experiment Results The comparison shows that the No. 1 nursery pond using the method of this invention is significantly better than the No. 2 and No. 3 nursery ponds in terms of shrimp larvae survival rate, growth indicators and water quality purification.

[0038] In summary, the present invention has the following beneficial effects: 1. Significant water purification effect: Through the synergistic effect of microalgae and probiotics under specific light conditions, it can effectively remove harmful substances such as ammonia nitrogen and nitrite from the water. Microalgae absorb nutrients such as nitrogen and phosphorus through photosynthesis and convert them into their own biomass, thereby reducing the concentration of nutrients in the water. Probiotics further purify the water by decomposing organic matter and participating in nitrogen cycling. 2. Promotes shrimp larvae growth and development: As high-quality natural feed, *Chaetoceros muelleri*, *Chaetoceros muelleri*, and small diatoms provide shrimp larvae with abundant protein, polysaccharides, unsaturated fatty acids, and vitamins, meeting their nutritional needs during growth. Simultaneously, a suitable water environment facilitates digestion, absorption, and metabolism, promoting growth rate and health. Short-term UVA irradiation can increase weight gain and feed conversion rate. Compared to traditional breeding methods, shrimp larvae cultivated using this invention show significant improvements in body length and weight growth indicators, increasing the survival rate by 10-20%. 3. Enhance shrimp immunity: Probiotics such as photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis form beneficial microbial communities in the water, inhibiting the growth and reproduction of harmful microorganisms, especially Vibrio and fungi, reducing the risk of shrimp larvae getting "dirty" and contracting diseases. In addition, probiotics can also regulate the intestinal microecological balance of shrimp, enhance the immunity and disease resistance of shrimp larvae, thereby effectively reducing the incidence of disease in shrimp larvae during the breeding process and improving the quality and stability of Litopenaeus vannamei breeding. 4. Ecological, Environmentally Friendly, and Sustainable: This invention utilizes biological methods such as microalgae and probiotics for water quality control, avoiding the extensive use of chemical agents and reducing potential harm to the aquatic environment and shrimp larvae. This aligns with the development philosophy of green, environmentally friendly, and sustainable aquaculture. Simultaneously, by precisely controlling environmental conditions such as light, the growth and function of microalgae and probiotics are optimized, improving the utilization efficiency of biological resources and significantly extending the effective action time of algae and bacteria. This avoids frequent addition of algae and bacteria, reducing workload. Spectral matching technology can increase microalgae biomass, enhancing shrimp larvae self-sufficiency in feed; reducing the cost of formulated feed; and solving pain points in larvae breeding such as algae bloom collapse on rainy days. This improves larvae quality and breeding stability, resulting in significant economic and social benefits.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the design concept of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for raising shrimp larvae under specific lighting conditions using microalgae and probiotics to regulate water quality, characterized in that, The steps include the following: Step 1: Construction of the Seedling Workshop: Construct a dedicated seedling workshop for Litopenaeus vannamei. A uniformly laid translucent panel and a shading device located on the upper side of the panel are fixedly connected to the roof of the seedling workshop. The workshop includes a shrimp larvae rearing area and a microalgae-probiotic rearing area compatible with the shrimp larvae rearing area. The shrimp larvae rearing area has several rearing ponds, each measuring 5m × 4m × 1.5m. Each rearing pond is equipped with a compatible light sensor and a first LED light group. The first LED light group includes a compatible first blue light module, a first red light module, and a UVA module. The microalgae-probiotic production area has several microalgae cultivation tanks and several probiotic cultivation tanks, temperature control equipment compatible with the microalgae and probiotic cultivation tanks, and a second LED light group. The second LED light group includes a second red light module and a second blue light module that respectively generate red and blue light. Both the second and first LED light groups are waterproof. Step 2: Microalgae-Probiotic Cultivation: The microalgae selected are Chlorella vulgaris, Chaetoceros muelleri, and Diatomella fusiforme. The probiotics selected are photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis. The selected Chlorella vulgaris, Chaetoceros muelleri, and Diatomella fusiforme are respectively inoculated into the microalgae cultivation tank to obtain microalgae solution. The selected photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis are respectively inoculated into the probiotic cultivation tank to obtain probiotic solution. Step 3, Preparation for Seedling Stocking: Before raising shrimp seedlings, thoroughly clean and disinfect the seedling pond. First, use a high-pressure water gun to rinse the pond walls and bottom to remove debris and dirt. Then, soak the pond in a 20-30 ppm available chlorine bleaching powder solution for 2-3 hours. After that, rinse the seedling pond with clean water. Finally, inject an appropriate amount of shrimp seedling raising water into the seedling pond. The initial water depth in the seedling raising water should be controlled at 0.7-0.8 m, the pH value should be set at 8.2, and the water temperature should be controlled at 30℃. Step 4: Release shrimp larvae: Evenly release an appropriate number of shrimp larvae into the nursery pond. The released shrimp larvae should be in the nauplius stage. Step 5: Algae-Probiotic Addition: After introducing shrimp larvae, add algae solution of *Gynostemma pentaphyllum*. When the shrimp larvae develop into zoea larvae, add algae solution of *Chaetoceros muelleri*. Then, when the shrimp larvae develop into mysid larvae, add algae solution of diatoms. The dosage of each algae solution is 50L, and the algae solution should be evenly sprinkled in the nursery pond. At the same time, after each type of microalgae solution is added, photosynthetic bacteria, Bacillus subtilis, and Enterococcus faecalis bacterial solutions are added in sequence. The dosage of each bacterial solution is 0.5L, and the bacterial solutions should be diluted with an appropriate amount of water before being evenly sprinkled throughout the pond. Step Six: Seedling Light Control: For the first 3 days after the introduction of microalgae and probiotics, the light intensity in the seedling pond should be controlled at 3000-5000 lx, with a light cycle of 14 hours of light and 10 hours of darkness. After 3 days, adjust the light intensity and light cycle appropriately based on the growth of microalgae and the transparency of the water. If the microalgae in the seedling pond grow too vigorously and the water transparency decreases, reduce the light intensity to 3000-4000 lx and set the light cycle to 12 hours of light and 12 hours of darkness. If the microalgae in the seedling pond grow slowly, increase the light intensity to 6000-8000 lx and set the light cycle to 16 hours of light and 8 hours of darkness. Step 7: Feeding Shrimp Larvae: When shrimp larvae develop into zoea larvae, feed them high-grade shrimp chips and No. 0 cypermethrin, and wash them with a 250-160 mesh net, feeding 1-2g per cubic meter of water; when shrimp larvae develop into zoea larvae stage II, feed them brine shrimp, with a feeding amount of 2-4 per shrimp larvae; when shrimp larvae develop into mysid larvae, feed them No. 2 shrimp chips and No. 0 cypermethrin, and wash them with a 120-100 mesh net, feeding 2-3g per cubic meter of water, while also feeding them brine shrimp, with a feeding amount of 4-7 per shrimp larvae; when shrimp larvae develop into roe shrimp larvae, feed them No. 5 shrimp chips and No. 1 cypermethrin, and wash them with an 80-40 mesh net, feeding 3-5g per cubic meter of water, while also feeding them live brine shrimp, with a feeding amount of 8-20 per shrimp larvae. Step 8: Water quality monitoring and control: Monitor various water quality indicators in the seedling pond regularly every day, and make corresponding adjustments based on the monitored water quality indicators; Step 9: Shrimp larvae evaluation and release: The survival rate, body length, and weight growth indicators of shrimp larvae are recorded and collected using a sampling statistical method. Based on the survival rate, body length, and weight growth indicators, it is determined whether the shrimp larvae meet the criteria for release. Those that meet the criteria are released, while those that do not meet the criteria continue to be cultivated until they reach the criteria for release. In step six, from 05:00 to 07:00 daily, the seedling pond is irradiated with ultraviolet light generated by the UVA module in the first LED light group; from 08:00 to 18:00 daily, the light in the seedling pond is mainly natural light coming in from the roof, and the light intensity in the seedling workshop is dynamically adjusted by the light sensor in conjunction with the shading device. If the light intensity is weak on cloudy or rainy days, the seedling pond is supplemented with natural light by the first LED light group to achieve a suitable light intensity; from 19:00 to 22:00 daily, the seedling pond is supplemented with red light generated by the first red light module.

2. The shrimp larvae rearing method for regulating water quality using microalgae and probiotics under specific light conditions according to claim 1, characterized in that, The light-transmitting panel is a polycarbonate hollow panel with a UV coating and a light transmittance of 70%. A prism refractive film is also attached to the surface of the light-transmitting panel. The shading device uses an electrically folding PE shading net with a light transmittance of 30-80%.

3. The shrimp larvae rearing method for regulating water quality using microalgae and probiotics under specific light conditions according to claim 2, characterized in that, The seedling pool is made of fiberglass and has a rectangular structure. A drain outlet is provided at one corner of the bottom of the seedling pool. The bottom of the seedling pool is angled towards the drain outlet. All corners of the seedling pool are rounded. Each seedling pool is equipped with a matching light sensor and a first LED light group. The first LED light group includes a matching first blue light module, a first red light module, and a UVA module.

4. The shrimp larvae rearing method for regulating water quality using microalgae and probiotics under specific light conditions according to claim 3, characterized in that, The culture methods for each microalga in step two are as follows: 1) When culturing *Chlorophytum comosum*, use f / 2 medium prepared with natural seawater. Pour the boiled and cooled medium into the microalgae culture tank, disinfect with chlorine-containing disinfectant tablets, and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then, inoculate *Chlorophytum comosum* in the logarithmic growth phase at an inoculation density of 1×10⁻⁶. 4 -3×10 4 The culture temperature was maintained at 18-25℃ using the temperature control device, and the light intensity was controlled at 5000-7000 lx. Irradiation was provided by a second LED lamp group generating blue light with a spectral wavelength of 450nm and red light with a spectral wavelength of 660nm. The light cycle was set to 16 hours of light and 8 hours of darkness. During the culture process, a blower and air stones were used for oxygenation to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reached 1×10⁻⁶ cells / mL, the culture was completed. 6 -2×10 6 When the concentration of *Clerodendrum trichotomum* is 100 cells / mL, a solution of *Clerodendrum trichotomum* that can be used for subsequent seedling bed placement is obtained and can be used for seedling bed placement. 2) When culturing Chaetoceros muelleri, f / 2 medium was used, prepared with natural seawater. The boiled and cooled medium was poured into the microalgae culture tank, disinfected with chlorine-containing disinfectant tablets, and then neutralized with sodium thiosulfate. Subsequently, Chaetoceros muelleri algae in the logarithmic growth phase were inoculated at an inoculation density of 2 × 10⁻⁶. 4 -4×10 4 The culture temperature was maintained at 18-25℃ using the temperature control device, and the light intensity was controlled at 3000-5000 lx. Irradiation was performed using blue light with a spectral wavelength of 470 nm generated by a second LED lamp group. The light cycle was set to 12 hours of light and 12 hours of darkness. During the culture process, oxygenation was carried out using a blower and air stones to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reached 2 × 10⁻⁶ cells / mL... 6 -3×10 6 When the concentration of cells / mL is reached, it can be used for placement in the aforementioned seedling pond; 3) For the cultivation of small diatoms, a special diatom culture medium prepared with natural seawater is used. The boiled and cooled culture medium is poured into the microalgae cultivation tank, disinfected with chlorine-containing disinfectant tablets, and then neutralized with sodium thiosulfate. Subsequently, small diatoms in the logarithmic growth phase are inoculated at an inoculation density of 1.5 × 10⁻⁶. 4 -3.5×10 4 The culture temperature was maintained at 20-25℃ using the temperature control device, and the light intensity was controlled at 5000-8000 lx. Irradiation was provided by a second LED lamp group generating blue light with a spectral wavelength of 450nm and red light with a spectral wavelength of 630nm. The light cycle was set to 14 hours of light and 10 hours of darkness. During the culture process, a blower and air stones were used for oxygenation to promote gas exchange and uniform distribution of nutrients. When the algal cell density of the microalgae solution reached 1.5 × 10⁻⁶ cells / mL, the culture was successfully completed. 6 -2.5×10 6 When the concentration of cells / mL is reached, it can be used for seedling placement in the aforementioned seedling pond.

5. The shrimp larvae rearing method for regulating water quality using microalgae and probiotics under specific light conditions according to claim 4, characterized in that, The culture methods for each probiotic culture in step two are as follows: 1) When culturing photosynthetic bacteria, use a special culture medium for photosynthetic bacteria. Dissolve one packet of culture medium and pour it into the probiotic culture tank, then fill it with sand-filtered seawater. Disinfect the tank with chlorine-containing disinfectant tablets and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then, inoculate the photosynthetic bacteria inoculum at a volume ratio of 5-10%. Maintain the culture temperature at 25-35℃ using the temperature control device, and control the light intensity at 10000-15000 lx. Irradiate with blue light at 470nm and red light at 800nm. Set the light cycle to 14 hours of light and 10 hours of darkness. Stir regularly during the culture process to ensure full contact between the bacteria and the culture medium. When the OD660 value of the probiotic solution reaches 0.8-1.2, it indicates that the photosynthetic bacteria are growing well and can be used in the seedling pond. 2) When culturing Bacillus subtilis, brown sugar is used for expansion and fermentation. Two kilograms of brown sugar are dissolved and poured into the probiotic culture tank, which is then filled with sand-filtered seawater. The tank is disinfected with chlorine-containing disinfectant tablets, and the residual chlorine is neutralized with sodium thiosulfate after disinfection. Bacillus subtilis inoculum is then inoculated at a volume ratio of 3-5%. The tank opening is sealed with plastic wrap, and an air stone is placed inside for aeration. The temperature is maintained at 25-35℃ using the temperature control equipment. Fermentation lasts for 24-48 hours. When the probiotic concentration reaches 1×10⁻⁶... 9 -2×10 9 When the concentration is CFU / mL, it can be used for seedling cultivation in the aforementioned seedling pond; 3) For Enterococcus faecalis culture, use brown sugar for expansion and fermentation. Dissolve 2 catties of brown sugar and pour it into the probiotic culture tank, then fill it with sand-filtered seawater. Disinfect with chlorine-containing disinfectant tablets, and neutralize the residual chlorine with sodium thiosulfate after disinfection. Then inoculate with Enterococcus faecalis inoculum at a volume ratio of 4-6%. Stir thoroughly and seal the tank with plastic wrap. Maintain the temperature at 25-35℃ using the temperature control equipment. Culture under anaerobic conditions for 24-48 hours. When the probiotic concentration reaches 1×10⁻⁶... 9 -1.5×10 9 When the concentration of CFU / mL is reached, it can be used for seedling cultivation in the aforementioned seedling pond.

6. The shrimp larvae rearing method for regulating water quality using microalgae and probiotics under specific light conditions according to claim 5, characterized in that, In step three, seawater that has undergone sedimentation and sand filtration is injected into a water tank used for temporary storage and transfer. The salinity of the seawater is set to 25-35‰. Then, 20ppm bleaching powder is used to disinfect the seawater in the treatment tank for 2 hours, and an appropriate amount of sodium thiosulfate is sprinkled to neutralize the residual chlorine. Then, 10g / m3 of disodium EDTA is sprinkled. Finally, after aeration and sedimentation, the water for shrimp larvae rearing is obtained.

7. A method for raising shrimp larvae under specific light conditions using microalgae and probiotics to regulate water quality, as described in claim 6, characterized in that... The water quality indicators include water temperature, salinity, pH value, dissolved oxygen, ammonia nitrogen content, and nitrite content. Water temperature, salinity, pH value, and dissolved oxygen are measured using a WTW3410 multi-parameter water quality analyzer. Ammonia nitrogen content is determined using Nessler's reagent spectrophotometry, and nitrite content is determined using naphthylethylenediamine hydrochloride spectrophotometry.

8. The shrimp larvae rearing method for regulating water quality using microalgae and probiotics under specific light conditions according to claim 7, characterized in that, In step eight, when the water temperature is below 28℃, the water temperature should be appropriately increased using heating equipment; when the salinity is below 22‰ before the shrimp larvae develop into mysid larvae, the salinity should be adjusted by adding sea salt crystals; when the pH value is above 8.6, an appropriate amount of citric acid should be added for adjustment; when the pH value is below 7.8, quicklime should be used for adjustment; when the dissolved oxygen content is below 5mg / L, the oxygenation should be increased in time; when the ammonia nitrogen content exceeds 0.2mg / L or the nitrite content exceeds 0.1mg / L after the shrimp larvae develop into mysid larvae, the water should be changed appropriately, and the amount of water changed each time should not exceed 20% of the total water volume.

9. A method for raising shrimp larvae under specific light conditions using microalgae and probiotics to regulate water quality, as described in claim 8, is characterized in that... In step eight, it is also necessary to regularly observe the growth status and algal composition of the microalgae in the nursery pond, and after the shrimp larvae develop into fry, supplement the algae solution and bacterial solution once a week, with a supplementation amount of 50L of each algae solution and 1L of each bacterial solution.

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