A method for freshwater rearing of macrobrachium rosenbergii larvae based on ion balance regulation

Abstract

The present application relates to the field of aquaculture technology, and more particularly to a method for freshwater rearing of Macrobrachium rosenbergii larvae based on ion balance regulation. When the daphnia-like larvae develop to Z5 stage and the proportion of Z5 is more than 50%, body strengthening is performed; when the larvae develop to postlarvae and the metamorphosis rate is more than 80%, freshwater rearing is started, and the salinity of water is reduced to 5-10‰ by using ion balance freshwatering liquid; during the process, Ca 2+ : 100-120 mg / L, Mg 2+ : 300-360 mg / L, K + : 60-100 mg / L is maintained in the water; when the salinity is reduced to less than 5‰, freshwatering is continued to 0‰ by using the ion balance freshwatering liquid; during the process, Ca 2+ : 80-100 mg / L, Mg 2+ : 200-300 mg / L, K + : 30-60 mg / L is maintained in the water. The freshwater rearing method can improve the freshwater rearing survival rate and metamorphosis rate of Macrobrachium rosenbergii.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to a method for desalination of giant freshwater prawn larvae based on ion balance regulation. Background Technology

[0002] Giant freshwater prawns exhibit a biological characteristic of migrating between brackish and freshwater. Their larval development must take place in brackish water, while juveniles and adults live in freshwater. Therefore, in the artificial breeding process, it is necessary to gradually replace high-salinity water (14‰) with freshwater (0‰), which is a desalination process.

[0003] In existing technologies, the desalination of giant freshwater prawn larvae typically employs simple water exchange or flowing water methods, that is, gradually reducing the proportion of seawater and increasing the proportion of freshwater to lower salinity. However, this traditional method has the following significant drawbacks: (1) Ignoring the imbalance of ion specificity: Traditional desalination only focuses on the reduction of total salinity (osmotic pressure) and ignores the imbalance of different ions (such as K+). + Ca 2+ Mg 2+ An imbalance in the proportion of calcium and magnesium ions during freshwater replenishment can lead to problems. During metamorphosis, giant freshwater prawn larvae require large amounts of calcium and magnesium ions for shell hardening. If the concentration of these ions in the freshwater is too low, it can cause soft shells, molting difficulties, or even death.

[0004] (2) Excessive energy consumption for osmotic pressure regulation: Dramatic fluctuations in salinity force larvae to mobilize a large amount of energy for Na+ in the gills. + / K + - The operation of ATPase to maintain the body's osmotic pressure balance directly squeezes out the energy used for growth and immunity, resulting in weak constitution in young animals and susceptibility to bacterial infections.

[0005] (3) Lack of stress-resistant synergistic mechanism: Existing technologies lack targeted stress-resistant nutrition or water quality control measures during the desalination process, resulting in unstable desalination survival rate, which usually hovers around 30%-50%, seriously restricting the seedling production benefits. Summary of the Invention

[0006] The purpose of this invention is to provide a desalination method for giant freshwater prawn larvae based on ion balance regulation, which aims to solve the problems of ion imbalance and heavy osmotic pressure regulation burden caused by simply reducing salinity in the prior art. By constructing a composite regulation system of ion buffering, energy supplementation and gradient pressure reduction, the survival rate of desalination is significantly improved.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for desalination of giant freshwater prawn larvae based on ion balance regulation, comprising the following steps: (1) When the zoea larvae of giant freshwater prawns develop to the Z5 stage during the seedling stage and the proportion of Z5 is more than 50%, physical enhancement is carried out; (2) When the giant freshwater prawns in step (1) have been raised to the larval stage and the metamorphosis rate has reached more than 80%, desalination begins. Using an ion-balanced desalination solution, the salinity of the water is gradually reduced to 5-10‰. During this period, the Ca concentration in the water is maintained. 2+ Concentration of 100~120 mg / L, Mg 2 + Concentration of 300~360 mg / L, K + The concentration is 60~100 mg / L; (3) When the salinity drops below 5‰, continue to desalinate with ion-balanced desalination solution until the salinity reaches 0‰; during this period, maintain the Ca content in the water. 2+ Concentration of 80~100 mg / L, Mg 2+ Concentration of 200~300 mg / L, K + The concentration is 30~60 mg / L.

[0008] Optionally, during the physical enhancement process, the water salinity is 10–14‰; the Ca content in the water... 2+ Concentration of 120~160 mg / L, Mg 2+ Concentration of 360~480 mg / L, K + The concentration is 100~150 mg / L.

[0009] Optionally, during the physical enhancement process, vitamin C phosphate and glucose are added; the amount of vitamin C phosphate added is 0.3~0.5 g / m³. 3 The vitamin C phosphate ester is added once every 5 days, for a total of 2 times. The amount of glucose added is 10~30g / m³. 3 .

[0010] Optionally, during the seedling raising process, the water temperature is 28~30℃, the water pH is 7.8~8.2, and the dissolved oxygen in the water is ≥6.0 mg / L.

[0011] Optionally, the ion-balanced desalination solution is prepared by measuring the Ca content in the seawater dilution solution at the target salinity. 2+ Mg 2+ K + The concentration of magnesium sulfate, potassium chloride and calcium oxide is determined based on the measured concentration. The required amounts of magnesium sulfate, potassium chloride and calcium oxide are then calculated and weighed. The weighed components are added together with glucose into the desalination water and stirred to dissolve.

[0012] Optionally, the fading in step (2) includes two stages: First stage of desalination: Salinity gradually decreases from 12‰ to 8‰; The second stage of desalination: the salinity gradually decreases from 8‰ to 3‰; Both the first and second stages of desalination maintained the Ca content in the water. 2+ Concentration of 100~120 mg / L, Mg 2+ Concentration of 300~360 mg / L, K + The concentration is 60~100 mg / L.

[0013] Optionally, in step (3), desalination involves gradually reducing the salinity from 3‰ to 0‰; In step (3), the desalination process involves slowly injecting fresh water using a bottom microporous aeration system, which is completed within 24 hours.

[0014] Optionally, the first stage of desalination involves replacing 10-15% of the total pool water volume daily for 3 days.

[0015] Optionally, the second stage of desalination involves changing the water three times a day, with each change replacing 3% of the total pool volume, and supplementing the water with 20-30 g / m³ of glucose. 3 .

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) By pre-adjusting the ratio of potassium, calcium and magnesium in desalinated water, the molting difficulties and soft shell disease caused by calcium deficiency in larvae under low salinity were avoided, and the uniformity of the size of the juvenile shrimp was significantly improved.

[0017] (2) Utilizing glucose as an exogenous energy supplement, combined with ion balancers, effectively reduced Na+ in the gills of juveniles. + / K + The increased activity load of ATPase allows larvae to dedicate more energy to growth and immunity, reducing fading and seedling drop.

[0018] (3) Using this method to raise freshwater prawns, the survival rate after freshwater acclimatization can be steadily increased to over 85%~90%, and the prawns are vigorous and have significantly improved adaptability to the subsequent freshwater aquaculture environment. Detailed Implementation

[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0024] All raw materials used in this invention can be obtained commercially or prepared using existing technologies.

[0025] This invention provides a method for desalination of giant freshwater prawn larvae based on ion balance regulation, comprising the following steps: (1) When the zoea larvae of giant freshwater prawns develop to the Z5 stage during the seedling stage and the proportion of Z5 is more than 50%, physical enhancement is carried out; (2) When the giant freshwater prawns in step (1) have been raised to the larval stage and the metamorphosis rate has reached more than 80%, desalination begins. Using an ion-balanced desalination solution, the salinity of the water is gradually reduced to 5-10‰ (for example, 5‰, 6‰, 7‰, 8‰, 9‰ or 10‰, etc.); during this period, the Ca in the water is maintained. 2+ Concentration of 100~120 mg / L (e.g., 100 mg / L, 110 mg / L, or 120 mg / L, etc.), Mg 2+Concentrations of 300–360 mg / L (e.g., 300 mg / L, 310 mg / L, 320 mg / L, 330 mg / L, 340 mg / L, 350 mg / L, or 360 mg / L, etc.), K + The concentration is 60~100 mg / L (for example, it can be 60 mg / L, 70 mg / L, 80 mg / L, 90 mg / L or 100 mg / L, etc.). (3) When the salinity drops below 5‰, continue to desalinate with ion-balanced desalination solution until the salinity reaches 0‰; during this period, maintain the Ca content in the water. 2+ Concentration of 80~100 mg / L (e.g., 80 mg / L, 90 mg / L, or 100 mg / L, etc.), Mg 2+ Concentrations of 200-300 mg / L (e.g., 200 mg / L, 220 mg / L, 250 mg / L, 280 mg / L, or 300 mg / L, etc.), K + The concentration is 30~60 mg / L (for example, it can be 30 mg / L, 40 mg / L, 50 mg / L or 60 mg / L, etc.).

[0026] In a preferred embodiment of the present invention, a combined regulation method of deep-sea water and ion balancer is used during the desalination process to maintain the Ca2+ level at each stage. 2+ Mg 2+ and K + Within the above range, the osmotic pressure of the shrimp's body fluid remains stable, reducing freshwater stress and improving the survival rate during freshwater acclimatization and subsequent adaptability to freshwater aquaculture.

[0027] In this invention, during the physical enhancement process, the salinity of the water is 10-14‰, for example, it can be 10‰, 11‰, 12‰, 13‰, or 14‰, etc.; the Ca content in the water... 2+ Concentrations of 120–160 mg / L (e.g., 120 mg / L, 130 mg / L, 140 mg / L, 150 mg / L, or 160 mg / L, etc.), Mg 2+ Concentrations of 360–480 mg / L (e.g., 360 mg / L, 380 mg / L, 400 mg / L, 420 mg / L, 450 mg / L, or 480 mg / L, etc.), K + The concentration is 100~150 mg / L (for example, it can be 100 mg / L, 110 mg / L, 120 mg / L, 130 mg / L, 140 mg / L or 150 mg / L, etc.).

[0028] In this invention, during the physical enhancement process, vitamin C phosphate and glucose are added; the amount of vitamin C phosphate added is 0.3~0.5 g / m³. 3 For example, it can be 0.3 g / m 3 0.4 g / m 3 or 0.5 g / m 3 The vitamin C phosphate ester mentioned above should be added once every 5 days, for a total of 2 times; The amount of glucose added is 10~30g / m³. 3 For example, it can be 10g / m 3 15g / m 3 20g / m 3 25g / m 3 Or 30g / m 3 wait.

[0029] In this invention, during the seedling cultivation process, the water temperature is 28~30℃, for example, 28℃, 29℃ or 30℃, the pH of the water is 7.8~8.2, for example, 7.8, 7.9, 8, 8.1 or 8.2, and the dissolved oxygen of the water is ≥6.0 mg / L.

[0030] In this invention, the ion-balanced desalination solution is prepared by the following method: measuring the Ca content in the seawater dilution solution at the target salinity. 2+ Mg 2+ K + The concentration of magnesium sulfate, potassium chloride and calcium oxide is determined based on the measured concentration. The required amounts of magnesium sulfate, potassium chloride and calcium oxide are then calculated and weighed. The weighed components are added together with glucose into the desalination water and stirred to dissolve.

[0031] In this invention, the fading process in step (2) includes two stages: First stage of desalination: Salinity gradually decreases from 12‰ to 8‰; The second stage of desalination: the salinity gradually decreases from 8‰ to 3‰; Both the first and second stages of desalination maintained the Ca content in the water. 2+ Concentration of 100~120 mg / L (e.g., 100 mg / L, 110 mg / L, or 120 mg / L, etc.), Mg 2+ Concentrations of 300–360 mg / L (e.g., 300 mg / L, 310 mg / L, 320 mg / L, 330 mg / L, 340 mg / L, 350 mg / L, or 360 mg / L, etc.), K + The concentration is 60~100 mg / L (for example, it can be 60 mg / L, 70 mg / L, 80 mg / L, 90 mg / L or 100 mg / L, etc.).

[0032] In this invention, in step (3), desalination involves gradually reducing the salinity from 3‰ to 0‰; In step (3), the desalination process involves slowly injecting fresh water using a bottom microporous aeration system, which is completed within 24 hours.

[0033] In this invention, the first stage of desalination is as follows: the daily water exchange volume is 10-15% of the total pool water volume, for example, it can be 10%, 11%, 12%, 13%, 14% or 15%, etc., and the desalination lasts for 3 days.

[0034] In this invention, the second stage of desalination involves changing the water three times a day, with each change replacing 3% of the total pool water volume, and supplementing the water with 20-30 g / m³ of glucose. 3 For example, it can be 20 g / m 3 25 g / m 3 Or 30 g / m 3 wait.

[0035] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0036] Example 1 (1) Diminish pre-existing physical condition and strengthen When the zoea larvae of the giant freshwater prawn develop to the Z5 stage during the seedling stage and the proportion of Z5 reaches more than 50%, physical strengthening begins.

[0037] Add vitamin C phosphate to the seedling bed at a rate of 0.4 g / m³. 3 Add once every 5 days, for a total of 2 times, while simultaneously supplementing the seedling water with glucose at a rate of 15 g / m³. 3 .

[0038] By adding deep-sea water and mineral salts to adjust the ion composition of the water, the following ion concentrations are maintained in the seedling water: Ca 2+ The concentration was 140 mg / L; Mg 2+ The concentration was 420 mg / L; K + The concentration is 120 mg / L; During the seedling stage, maintain a salinity of 12‰, a water temperature of 29±1℃, a pH of 7.8~8.2, and dissolved oxygen ≥6.0 mg / L.

[0039] The above-mentioned enhanced treatment can improve the stress resistance of shrimp larvae, laying the foundation for subsequent freshwater acclimatization.

[0040] (2) Preparation of ion-balanced desalination solution Prepare an ion-balanced desalination solution.

[0041] Ion balancers include: magnesium sulfate heptahydrate; potassium chloride; calcium oxide; and glucose.

[0042] Determination of Ca in seawater dilution at target salinity 2+ Mg 2+ K + The concentration of magnesium sulfate, potassium chloride, and calcium oxide is determined; based on the measured concentration, the required amounts of magnesium sulfate, potassium chloride, and calcium oxide are calculated and weighed; the weighed components are added together with glucose to the desalination water, stirred and dissolved to obtain the ion-balanced desalination solution. The Ca in the ion-balanced desalination solution... 2+ Mg 2+ K + The concentration is basically consistent with the ion ratio in the seawater dilution at the target salinity, thus avoiding a sudden drop in the concentration of a single ion during the desalination process.

[0043] (3) First stage of dilution (12‰→8‰) When the metamorphosis rate of juvenile shrimp reaches 80% or more, they begin to desalinate.

[0044] The daily water exchange volume is controlled at 12% of the total pool volume, and ion-balanced desalination solution is used for replenishment to gradually reduce the water salinity from 12‰ to 8‰.

[0045] This phase is maintained: Ca 2+ Concentration of 120 mg / L; Mg 2+ The concentration was 360 mg / L; K + The concentration is 100 mg / L; The desalination process lasted approximately 3 days, reducing the salinity to 8‰.

[0046] (4) Second stage of dilution (8‰→3‰) Once the salinity drops to 8‰, a continuous small-volume desalination method is adopted.

[0047] The water is changed three times a day, with each change replacing 3% of the total volume of the pool water. Ion-balanced desalination solution is used to replenish the water, gradually reducing the salinity from 8‰ to 3‰.

[0048] Simultaneously, supplement the water body with 20-30 g / m³ of glucose. 3 This enhances the ability of juvenile shrimp to resist osmotic stress.

[0049] This phase is maintained: Ca 2+ Concentration of 100 mg / L; Mg 2+ The concentration is 300 mg / L; K + The concentration is 60 mg / L.

[0050] (5) Third stage of dilution (3‰→0‰) When the salinity drops below 3‰, stop regular water changes.

[0051] Fresh water is slowly injected using a bottom microporous aeration system, and the salinity transition is completed through natural water convection.

[0052] The salinity gradually decreased from 3‰ to 0‰ within 24 hours.

[0053] Maintain during desalination: Ca 2+ Concentration of 90 mg / L; Mg 2+ The concentration is 250 mg / L; K + The concentration is 40 mg / L.

[0054] After the desalination is completed, continue to raise the shrimp for 24 hours and observe their feeding, swimming and metamorphosis.

[0055] Example 2 (1) Diminish pre-existing physical condition and strengthen When the zoea larvae of the giant freshwater prawn develop to the Z5 stage during the seedling stage and the proportion of Z5 reaches more than 50%, physical strengthening begins.

[0056] Add vitamin C phosphate to the seedling bed at a rate of 0.4 g / m³. 3 Add the solution once every 5 days, for a total of 2 times. Simultaneously, supplement the seedling water with glucose at a rate of 15 g / m³. 3 .

[0057] By adding deep-sea water and mineral salts to adjust the ion composition of the water, the following ion concentrations are maintained in the seedling water: Ca 2+ The concentration was 140 mg / L; Mg 2+ The concentration was 420 mg / L; K + The concentration is 120 mg / L; During the seedling stage, maintain a salinity of 10-14‰, a water temperature of 29±1℃, a pH of 7.8-8.2, and dissolved oxygen ≥6.0 mg / L.

[0058] The above-mentioned enhanced treatment can improve the stress resistance of shrimp larvae, laying the foundation for subsequent freshwater acclimatization.

[0059] (2) Preparation of ion-balanced desalination solution Prepare an ion-balanced desalination solution.

[0060] Ion balancers include: magnesium sulfate heptahydrate; potassium chloride; calcium oxide; and glucose.

[0061] Determination of Ca in seawater dilution at target salinity 2+ Mg 2+ K +The concentration of magnesium sulfate, potassium chloride, and calcium oxide is determined; based on the measured concentration, the required amounts of magnesium sulfate, potassium chloride, and calcium oxide are calculated and weighed; the weighed components are added together with glucose to the desalination water, stirred and dissolved to obtain the ion-balanced desalination solution. The Ca in the ion-balanced desalination solution... 2+ Mg 2+ K + The concentration is basically consistent with the ion ratio in the seawater dilution at the target salinity, thus avoiding a sudden drop in the concentration of a single ion during the desalination process.

[0062] (3) Initial stage of dilution (10‰→5‰) When the metamorphosis rate of juvenile shrimp reaches 80% or more, they begin to desalinate.

[0063] The daily water exchange volume is controlled at 12% of the total pool volume, and ion-balanced desalination solution is used for replenishment to gradually reduce the water salinity from 10‰ to 5‰.

[0064] This phase is maintained: Ca 2+ The concentration was 110 mg / L; Mg 2+ The concentration was 330 mg / L; K + The concentration is 80 mg / L; The desalination process lasted approximately 3 days, reducing the salinity to 5‰.

[0065] (4) Late stage of dilution (5‰→0‰) Once the salinity drops to 5‰, a continuous small-volume desalination method is adopted.

[0066] The water is changed three times a day, with each change replacing 3% of the total volume of the pool water. Ion-balanced desalination solution is used to replenish the water, gradually reducing the salinity from 5‰ to 0‰.

[0067] Simultaneously, supplement the water body with 25 g / m³ of glucose. 3 This enhances the ability of juvenile shrimp to resist osmotic stress.

[0068] This phase is maintained: Ca 2+ Concentration of 90 mg / L; Mg 2+ The concentration is 250 mg / L; K + The concentration is 40 mg / L.

[0069] After the desalination is completed, continue to raise the shrimp for 24 hours and observe their feeding, swimming and metamorphosis.

[0070] Example 3 The only difference from Example 2 is that step (1) pre-desalination physical enhancement: maintaining the following ion concentrations in the seedling water: Ca 2+ Concentration of 150 mg / L; Mg 2+ The concentration was 480 mg / L; K +The concentration is 130 mg / L; Step (3) Initial dilution phase: This phase is maintained at: Ca 2+ The concentration was 110 mg / L; Mg 2+ The concentration was 360 mg / L; K + The concentration is 90 mg / L; Step (4) Fading phase: This stage maintains: Ca 2+ Concentration of 100 mg / L; Mg 2+ The concentration is 300 mg / L; K + The concentration was 50 mg / L; glucose was supplemented at 30 g / m³ during the later stages of dilution. 3 .

[0071] The remaining steps and parameters are the same as in Example 1.

[0072] Example 4 The only difference from Example 2 is that step (1) pre-desalination physical enhancement: maintaining the following ion concentrations in the seedling water: Ca 2+ Concentration of 120 mg / L; Mg 2+ The concentration was 360 mg / L; K + The concentration is 100 mg / L; Step (3) Initial dilution phase: This phase is maintained at: Ca 2+ Concentration of 100 mg / L; Mg 2+ The concentration is 300 mg / L; K + The concentration is 60 mg / L; Step (4) Fading phase: This stage maintains: Ca 2+ Concentration of 80 mg / L; Mg 2+ The concentration is 200 mg / L; K + The concentration was 30 mg / L; glucose was supplemented at 20 g / m³ during the later stages of dilution. 3 Lower concentration The remaining steps and parameters are the same as in Example 1.

[0073] Comparative Example 1 The only difference from Example 2 is that desalination begins when the metamorphosis rate of the juvenile shrimp reaches over 80%. Freshwater is used directly for desalination without ion replenishment, and salinity is adjusted as shown in Table 1. When the salinity is 0, the concentration of core ions in the water will be close to 0.

[0074] Table 1. Salinity and Corresponding Ion Concentrations

[0075] Test Example 1 Examples 1-3 and Comparative Example 1 all used the same batch of healthy giant freshwater prawn daphnia larvae, with 2500 larvae in each group and 3 replicates. The survival rate and metamorphosis rate of the giant freshwater prawns were calculated according to the following formula: Survival rate (%) = (Number of surviving tails / Initial number of tails) × 100%; Metamorphosis rate (%) = Number of completed metamorphosis tails / Initial tails × 100%.

[0076] The survival rate and metamorphosis rate of giant freshwater prawns cultured in Examples 1-3 and Comparative Example 1 are shown in Table 2.

[0077] Table 2 shows the calculation results of the survival rate and metamorphosis rate of giant freshwater prawns cultured in Examples 1-4 and Comparative Example 1.

[0078] Table 1 shows that the method in Example 1 is suitable for conventional seedling cultivation, with a survival rate of 92.4%. Compared with Example 1, Example 2, under different initial salinity and desalination steps, can still achieve a good desalination effect as long as the ion balance and core concentration described in this invention remain unchanged. Example 3, to further improve osmotic pressure resistance, compared with Example 1, increased Mg... 2+ The ion content improved the survival rate of giant freshwater prawns (Macrobrachium rosenbergii) to 94.6%, enhancing their transport tolerance and making them suitable for long-distance seedling transport. Example 4, compared to Example 1, reduced the amount of added mineral salts, resulting in a giant freshwater prawn survival rate of 89.3% and a production cost reduction of approximately 15%, making it suitable for large-scale hatcheries. Comparative Example 1, compared to Example 1, used deep seawater diluted with fresh water without ion supplementation, resulting in a giant freshwater prawn survival rate of 74.3% and a metamorphosis rate of 68.5%. This demonstrates that the present invention improves the survival rate and metamorphosis rate of giant freshwater prawns by pre-adjusting the potassium, calcium, and magnesium ratio in the desalinated water.

[0079] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for desalination of giant freshwater prawn larvae based on ion balance regulation, characterized in that, Includes the following steps: (1) When the zoea larvae of giant freshwater prawns develop to the Z5 stage during the seedling stage and the proportion of Z5 is more than 50%, physical enhancement is carried out; (2) When the giant freshwater prawns in step (1) have been raised to the larval stage and the metamorphosis rate has reached more than 80%, desalination begins. Using an ion-balanced desalination solution, the salinity of the water is gradually reduced to 5-10‰. During this period, the Ca concentration in the water is maintained. 2+ Concentration of 100~120 mg / L, Mg 2+ Concentration of 300~360 mg / L, K + The concentration is 60~100 mg / L; (3) When the salinity drops below 5‰, continue to desalinate to 0‰ using ion-balanced desalination solution; during this period, maintain the Ca content in the water. 2+ Concentration of 80~100 mg / L, Mg 2+ Concentration of 200~300 mg / L, K + The concentration is 30~60 mg / L.

2. The method according to claim 1, characterized in that, During the physical enhancement process, the water salinity is 10–14‰; the Ca content in the water... 2+ Concentration of 120~160 mg / L, Mg 2+ Concentration of 360~480 mg / L, K + The concentration is 100~150 mg / L.

3. The method according to claim 1, characterized in that, During the physical enhancement process, vitamin C phosphate and glucose are added; the amount of vitamin C phosphate added is 0.3~0.5 g / m³. 3 The vitamin C phosphate ester is added once every 5 days, for a total of 2 times. The amount of glucose added is 10~30g / m³. 3 .

4. The method according to claim 1, characterized in that, During the seedling cultivation process, the water temperature is 28~30℃, the pH of the water is 7.8~8.2, and the dissolved oxygen in the water is ≥6.0 mg / L.

5. The method according to claim 1, characterized in that, The ion-balanced desalination solution is prepared by the following method: measuring the Ca content in the seawater dilution solution at the target salinity. 2+ Mg 2+ K + The concentration of magnesium sulfate, potassium chloride and calcium oxide is determined based on the measured concentration. The required amounts of magnesium sulfate, potassium chloride and calcium oxide are then calculated and weighed. The weighed components are added together with glucose into the desalination water and stirred to dissolve.

6. The method according to claim 2, characterized in that, The fading process in step (2) includes two stages: First stage of desalination: Salinity gradually decreases from 12‰ to 8‰; The second stage of desalination: the salinity gradually decreases from 8‰ to 3‰; Both the first and second stages of desalination maintained the Ca content in the water. 2+ Concentration of 100~120 mg / L, Mg 2+ Concentration of 300~360 mg / L, K + The concentration is 60~100 mg / L.

7. The method according to claim 6, characterized in that, In step (3), desalination involves gradually reducing the salinity from 3‰ to 0‰; In step (3), the desalination process involves slowly injecting fresh water using a bottom microporous aeration system, which is completed within 24 hours.

8. The method according to claim 6, characterized in that, The first stage of desalination involves replacing 10-15% of the total water volume in the pool daily, and the desalination process lasts for 3 days.

9. The method according to claim 6, characterized in that, The second stage of desalination involves changing the water three times a day, with each change replacing 3% of the total water volume, and supplementing the water with glucose at a rate of 20-30 g / m³. 3 .

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