Composite water body additive for domesticating parent fish of wild sal-family pseudosciaena crocea and application of composite water body additive

Abstract

The invention provides a composite water body additive for domesticating parent fish of wild sal-family pseudosciaena crocea and application of the composite water body additive, and belongs to the technical field of aquaculture. The composite water body additive is prepared from the following components in parts by mass: 0.02 to 0.06 part of gamma-aminobutyric acid, 3 to 8 parts of esterified vitamin C, 10 to 15 parts of broad-spectrum aquatic antibacterial medicine, 20 to 50 parts of magnesium sulfate and 5 to 10 parts of algal polysaccharide extract. According to the compound additive disclosed by the invention, through scientific combination of various functional components with a synergistic effect, the compound additive has three functional modules, namely an anti-stress function module, an antibacterial function module and a water body stabilizing function module, and multi-dimensional regulation and control on internal and external environments of parent fish of wild sal ammoniac pseudosciaena crocea can be realized on the premise of not influencing basic parameters of water quality; the death rate of parent fishes can be effectively reduced, the feeding rate is improved, and the domestication period is remarkably shortened.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture technology, and in particular relates to a compound aquatic additive for the domestication of wild large yellow croaker broodstock and its application. Background Technology

[0002] The large yellow croaker (Cyprinus naanensis) possesses excellent heat resistance, rapid growth potential, and ecological characteristics that allow it to adapt to deep-sea aquaculture environments, attracting widespread attention from the aquaculture breeding and farming sectors in recent years. To realize the development and industrial utilization of its germplasm resources, it is essential to obtain parent fish from wild populations and conduct artificial breeding. However, because these wild parent fish have long inhabited the complex natural marine environment, their physiological state is highly dependent on stable external light, temperature, salinity, and food composition.

[0003] During artificial capture, transportation, and temporary holding for domestication, broodstock inevitably experience multiple stressors, including net trapping, mechanical transport, intensive temporary holding, and high temperature and low oxygen levels. This easily triggers stress responses, manifesting as continuous rolling, ramming against walls to escape, bleeding from the body surface, increased mucus excretion, and even muscle stiffness and death. This high-intensity stress not only directly reduces the survival rate of broodstock but can also hinder gonadal development and disrupt hormone levels, severely impacting subsequent domestication and artificial spawning. Furthermore, under stress, the mucosal barrier function of broodstock decreases, and the aquatic microecology becomes unbalanced, creating opportunities for opportunistic pathogens such as Aeromonas hydrophila, Vibrio, and Streptococcus, greatly increasing the risk of outbreaks of bacterial infections.

[0004] Current solutions largely rely on simple methods such as temporary holding, temperature control and density reduction, or single-drug application, lacking a systematic and comprehensive aquatic environment control strategy. Especially under the premise of ensuring the health of broodstock, a synergistic water environment control technology that achieves "stress resistance, water quality stabilization, and pathogen suppression" remains lacking. Therefore, there is an urgent need to develop a scientifically formulated, easy-to-use, stable, and safe compound aquatic additive that can effectively buffer stress in broodstock, regulate endocrine and immune status, and prevent the growth of pathogenic microorganisms without damaging the basic physicochemical indicators of the water, thus providing a fundamental guarantee for the domestication and adaptation of broodstock and artificial breeding. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a compound aquatic additive for the domestication of wild Naozhou large yellow croaker broodstock and its application, to solve the problems that restrict the breeding success rate of wild Naozhou large yellow croaker broodstock during artificial capture, transportation and domestication, such as strong stress, low survival rate, slow feeding and susceptibility to pathogens.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A compound aquatic additive for the domestication of wild Naozhou large yellow croaker parent fish, comprising the following components by weight: 0.02-0.06 parts of γ-aminobutyric acid, 3-8 parts of esterified vitamin C, 10-15 parts of broad-spectrum aquatic antibacterial agent, 20-50 parts of magnesium sulfate, and 5-10 parts of seaweed polysaccharide extract.

[0007] Preferably, the broad-spectrum aquatic antibacterial drug is enrofloxacin.

[0008] This invention also provides the application of the above-mentioned composite aquatic additive in the domestication of wild large yellow croaker broodstock.

[0009] The present invention also provides a method for domesticating wild large yellow croaker broodstock, comprising the following steps: adding the above-mentioned compound aquatic additive to the aquaculture water, wherein the mass concentration of each component is γ-aminobutyric acid 0.02-0.06 mg / L, esterified vitamin C 3-8 mg / L, broad-spectrum aquatic antibacterial drug 10-15 mg / L, magnesium sulfate 20-50 mg / L, and seaweed polysaccharide extract 5-10 mg / L.

[0010] Preferably, the composite aquatic additive is added before the parent fish are transported to the holding tank or in the initial stage after they are introduced into the water.

[0011] Preferably, the composite water additive is first dissolved in a measured amount of seawater, stirred evenly, and then added to the aquaculture water.

[0012] Preferably, the aquaculture water is replaced every 45-50 hours, with a water replacement rate of ≥90%, and compound water additives are added again at the same time.

[0013] Preferably, the aquaculture water has a temperature of 22±0.5℃, a salinity of 19-22, a pH of 8.0-8.3, and dissolved oxygen ≥5.0mg / L.

[0014] Preferably, the aquaculture water is natural seawater that has been settled and filtered, and the addition of strong alkaline or acidic substances is prohibited, as is vigorous stirring.

[0015] Preferably, the acclimatization lasts for 5-7 days.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the composite additive of this invention, the anti-stress component γ-aminobutyric acid (GABA) can alleviate the excitation state of the central nervous system of broodstock by promoting nerve conduction regulation, stabilizing behavioral performance and cortisol secretion, thereby reducing stress response; esterified vitamin C, as an antioxidant, effectively scavenges free radicals and enhances the fish's resistance to stress; a broad-spectrum aquatic antibacterial agent can form a low-concentration, continuous barrier in the water, inhibiting the growth and reproduction of potential pathogens such as Vibrio and Aeromonas, preventing wound infection and mucosal damage; magnesium sulfate and seaweed polysaccharide extract, as water-stabilizing components, help regulate osmotic pressure, ion balance, and water buffering capacity, maintaining a good domestication environment. All components have a synergistic effect, possessing three major functional modules: anti-stress, antibacterial, and water stabilization, enabling multi-dimensional regulation of the internal and external environment of broodstock without affecting basic water quality parameters. The compound additive of this invention can be continuously applied at the recommended concentration throughout the entire process of broodstock domestication, exerting a significant effect from the transportation and temporary holding stage to the pre-gonadal induction stage. No additional equipment or complex operations are required during use; it simply needs to be dissolved and added to the aquaculture pond water according to the recommended ratio, exhibiting excellent ease of operation and adaptability. Through periodic water changes and re-addition, the concentration of the effective components can be kept dynamically stable, achieving long-term regulation and support for the physiological state of the broodstock and the aquatic microecology.

[0017] The addition of the compound additive and the domestication method of the present invention can effectively reduce the mortality rate of parent fish, increase their feeding rate, and significantly shorten the domestication cycle, creating favorable conditions for subsequent artificial spawning of wild large yellow croaker and obtaining high-quality fertilized eggs. Detailed Implementation

[0018] A compound aquatic additive for the domestication of wild Naozhou large yellow croaker parent fish, comprising the following components by weight: 0.02-0.06 parts of γ-aminobutyric acid, 3-8 parts of esterified vitamin C, 10-15 parts of broad-spectrum aquatic antibacterial agent, 20-50 parts of magnesium sulfate, and 5-10 parts of seaweed polysaccharide extract.

[0019] In this invention, the functions of each component are as follows: γ-Aminobutyric acid (GABA): As a neuromodulatory substance, it is used to alleviate stress in broodstock, stabilize behavior, and inhibit turbulence. Preferably, the amount of γ-aminobutyric acid is 0.03-0.05 parts, more preferably 0.04 parts.

[0020] Esterified vitamin C: a water-soluble antioxidant that can enhance the antioxidant capacity and immune function of broodstock, and reduce endogenous damage caused by transport and environmental mutations. Preferably, 4-6 parts of esterified vitamin C are used, more preferably 5 parts.

[0021] Broad-spectrum aquatic antibacterial drug: Inhibits common pathogens on the surface of broodstock, such as Aeromonas hydrophila and Vibrio spp., preventing wound or gill infections. Preferably, 13-14 parts of broad-spectrum aquatic antibacterial drug are used, more preferably 12 parts, and even more preferably, enrofloxacin is used.

[0022] Magnesium sulfate: can regulate the concentration of magnesium ions in water, improve the electrolyte balance of fish, and reduce osmotic stress caused by sudden changes in osmotic pressure. Preferably, 25-35 parts magnesium sulfate are used, more preferably 30 parts.

[0023] Seaweed polysaccharide extract: Rich in natural mucopolysaccharides and immune-enhancing factors, it can promote the formation of the intestinal mucosal barrier in fish and has certain antibacterial and water-stabilizing effects. Preferably, 7-9 parts of seaweed polysaccharide extract are used, with 8 parts being a more preferred amount.

[0024] The present invention does not have any special limitation on the source of the above components, which can be obtained through market channels.

[0025] This invention also provides the application of the above-mentioned composite aquatic additive in the domestication of wild large yellow croaker broodstock.

[0026] This invention also provides a method for domesticating wild large yellow croaker broodstock, comprising the following steps: adding the above-mentioned compound aquatic additive to the aquaculture water, wherein the mass concentration of each component is 0.02-0.06 mg / L of γ-aminobutyric acid, 3-8 mg / L of esterified vitamin C, 10-15 mg / L of broad-spectrum aquatic antibacterial agent, 20-50 mg / L of magnesium sulfate, and 5-10 mg / L of seaweed polysaccharide extract. Preferably, the mass concentration of each component is 0.04 mg / L of γ-aminobutyric acid, 5 mg / L of esterified vitamin C, 12 mg / L of broad-spectrum aquatic antibacterial agent, 30 mg / L of magnesium sulfate, and 8 mg / L of seaweed polysaccharide extract.

[0027] In this invention, it is preferable to add the compound water additive before the parent fish are transported to the holding tank or at the initial stage of their introduction into the water body; it is evenly preferable to dissolve the compound water additive in a measured amount of seawater first, stir it evenly, and then add it into the aquaculture water body to ensure the uniformity of the mixture.

[0028] In this invention, it is preferred that the aquaculture water be changed every 45-50 hours, with a water replacement volume of ≥90%, and at the same time, compound water additives are re-added; it is even more preferred that the water be changed every 48 hours.

[0029] In this invention, the preferred water temperature for aquaculture is 22±0.5℃, salinity is 19-22, pH is 8.0-8.3, and dissolved oxygen is ≥5.0mg / L; further preferred is that the aquaculture water is natural seawater that has been settled and filtered, and the addition of strong alkaline or acidic substances is prohibited, and vigorous stirring should be avoided.

[0030] In this invention, the domestication is preferably carried out for 5-7 days, and the specific time is adjusted according to the feeding recovery status of the parent fish.

[0031] 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.

[0032] Example 1 A compound aquatic additive for the domestication of wild Naozhou large yellow croaker broodstock, with the following components by weight: 0.04 parts of γ-aminobutyric acid, 5 parts of esterified vitamin C, 12 parts of enrofloxacin powder, 30 parts of magnesium sulfate, and 8 parts of seaweed polysaccharide extract.

[0033] Example 2 A compound aquatic additive for the domestication of wild Naozhou large yellow croaker broodstock, with the following components by weight: 0.02 parts of γ-aminobutyric acid, 3 parts of esterified vitamin C, 10 parts of enrofloxacin powder, 20 parts of magnesium sulfate, and 5 parts of seaweed polysaccharide extract.

[0034] Example 3 A compound aquatic additive for the domestication of wild Naozhou large yellow croaker broodstock, with the following components by weight: 0.06 parts of γ-aminobutyric acid, 8 parts of esterified vitamin C, 15 parts of enrofloxacin powder, 50 parts of magnesium sulfate, and 10 parts of seaweed polysaccharide extract.

[0035] Example 4 A method for domesticating wild Naozhou large yellow croaker parent fish, with a complete domestication cycle of 6 days, is as follows: (1) Premixing: Dissolve the composite water additive of Example 1 in a small amount of seawater for aquaculture and mix thoroughly to form a standard working solution; (2) Addition: Add the following to the entire pond water 2 hours before the wild broodstock are released into the temporary holding pond, so that the mass concentration of each component is 0.04 mg / L γ-aminobutyric acid, 5 mg / L esterified vitamin C, 12 mg / L enrofloxacin powder, 30 mg / L magnesium sulfate, and 8 mg / L seaweed polysaccharide extract; the wild broodstock are slowly transferred into the indoor temporary holding pond using plastic buckets; (3) Water replacement: In order to ensure water quality stability and maintain the concentration of effective ingredients, the entire pool water is replaced every 48 hours (water replacement volume ≥ 90%), and compound additives are replenished again in proportion. (4) Water environment control: During the acclimatization period, the water temperature is maintained at 22±0.5℃, the salinity is 19-22, the pH is 8.0-8.3, and the dissolved oxygen (DO) is ≥5.0mg / L. The water body can be maintained by aeration or microporous oxygenation system. (5) Operational precautions: Avoid mixing with strong alkaline or strong acidic substances. Use natural seawater that has been settled and filtered when using it. Avoid vigorous stirring after adding the additive to avoid inducing the fish to escape.

[0036] Performance and results statistics during domestication: Days 1-2: The parent fish swam around separately, with some individuals remaining still in the corner of the pond. There was no obvious rolling or jumping behavior, and no obvious damage to their body surface was observed. Day 3: Some individuals begin to swim more actively and exhibit active feeding behavior. After being lured with freshly chopped fish, the feeding rate is approximately 30-40%. Days 4-5: Fish behavior gradually stabilizes, feeding response time shortens, and group feeding rate exceeds 60%; Day 6: Feeding rate reached over 80%, fish had normal body luster and swam vigorously. A total of 33 fish died in the whole pond, and 87 parent fish survived; the final survival rate was 72.5%.

[0037] Comparative Example 1 The control group of broodstock was also selected from the waters off Naozhou Island, caught in the same batch, with a body weight ranging from 400-600g, and a quantity of 120 fish. The transportation method, anesthesia treatment, water temperature control, and the timing of transfer to the indoor holding tank were completely consistent with Example 4. The holding tank used was 20m in size. 3 Natural seawater after sedimentation and filtration was used as the water body, with initial water quality parameters of: water temperature 22.1℃, salinity 20.3, pH value 8.1, and dissolved oxygen 5.5 mg / L. No compound water additives were added to the control group throughout the acclimatization period, and all other operations, such as water change frequency, light cycle, and observation records, remained consistent with Example 4.

[0038] Performance and results statistics during domestication: Days 1-2: Fish exhibit abnormal activity, with some parent fish showing signs of continuous rolling, jumping to escape, and vigorous rubbing against the pond, and noticeable scale loss. Day 3: No obvious feeding response was observed in the whole pond. After feeding fresh miscellaneous fish, no individual fish ate. Some fish sank to the bottom or continued to hit the wall. The rate of body surface damage increased significantly. Days 4-5: Mass mortality begins to occur, individuals become sluggish and their gills turn pale, and the cumulative number of deaths increases to 38. Days 6-7: The fish population stabilized slightly, but still did not exhibit normal feeding behavior. A total of 51 fish died, leaving 69 surviving parent fish; the final survival rate was 57.5%.

[0039] Compared to Example 4, Comparative Example 1 exhibited more severe behavioral stress, persistent feeding inhibition, and high mortality during the acclimatization period. In Example 4, active feeding began on day 3, and the feeding rate recovered to over 80% by day 6, with a survival rate of 72.5%. In contrast, in Comparative Example 1, feeding did not recover by day 7, and the final survival rate was only 57.5%.

[0040] Comparative Example 2 120 wild-caught large yellow croaker broodstock from the same batch as in Example 4, weighing between 400-600g, were selected. The transportation and anesthesia methods were the same as in Example 4, and the acclimatization environment and water conditions were completely identical. They were released into a 20m... 3 The fish were placed in a temporary holding tank. Two hours before stocking, γ-aminobutyric acid (GABA) was added to the water at a concentration of 0.05 mg / L. No other components (esterified vitamin C, enrofloxacin, magnesium sulfate, and seaweed polysaccharide extract) were added. The water temperature was maintained at 22 ± 0.5℃, salinity at 20-21, pH at 8.0-8.3, and DO ≥ 5.0 mg / L. The acclimatization period was 6 days, with water changed and GABA replenished every 48 hours.

[0041] Performance and results statistics during domestication: Days 1-2: The parent fish swim relatively dispersed, their stress symptoms are slightly relieved, and their pond-rubbing behavior decreases; Day 3: Some individuals begin to regain their activity level, but their feeding response is weak, and the overall feeding rate does not exceed 25%. Days 4-5: Feeding gradually increases but recovery is slow, and some individuals still exhibit alternating behaviors of excitement and sinking to the bottom; Day 6: The total number of deaths was 44, and the number of surviving parent fish was 76; the final survival rate was 63.3%.

[0042] Although the use of γ-aminobutyric acid (GABA) alone can alleviate the nerve stress response of broodstock during transportation and the initial stage of pond transfer to some extent, its overall regulatory effect is significantly less than that of Example 4 due to the lack of antibacterial and water stabilization support. Especially in the middle and late stages of acclimatization, feeding behavior recovers slowly, ammonia nitrogen in the water increases slightly, and some individuals still show sluggish swimming and mild symptoms of body surface infection on the 5th and 6th days.

[0043] Comparative Example 3 120 wild-caught large yellow croaker broodstock, weighing 400-600g, were selected from the same batch as in Example 4. The transportation method, acclimatization pond specifications, water treatment method, and initial water quality conditions were consistent with Example 4. After the fish were transferred to an indoor cement holding tank, enrofloxacin powder was added to the water 2 hours before stocking at a concentration of 12mg / L. This additive is a conventional broad-spectrum aquatic antibacterial agent that can create a short-term antibacterial environment in the water. Other functional components (γ-aminobutyric acid, esterified vitamin C, magnesium sulfate, and seaweed polysaccharide extract) were not added. The acclimatization period was 6 days, with the water changed every 48 hours and enrofloxacin added proportionally.

[0044] Performance and results statistics during domestication: Days 1-2: Fish behavior was unstable, some parent fish continued to rub against the pond, some individuals swam and bumped into things, and 5 fish died; Day 3: No obvious feeding intention was observed. Only a few fish showed feeding after being lured with freshly chopped fish. Days 4-5: Mortality continued to increase, mild septicemia symptoms appeared, red spots appeared on the fish's body surface and white fins, suggesting that although antibacterial pressure existed, there were no other supporting components to buffer the stress; Day 6: Feeding behavior was sluggish, 72 parent fish survived, and 48 died; the final survival rate was 60.0%.

[0045] Compared to Example 4, although the broodstock in Comparative Example 3 showed some inhibitory effect on certain potential aquatic pathogens in the early stages, the lack of effective components to alleviate nerve stress, electrolyte water stabilization regulators, and immune support components resulted in overall behavioral disturbances, prolonged feeding inhibition, and a still high mortality rate. This demonstrates that while broad-spectrum antibiotics can inhibit bacterial growth in water for a short period, they cannot replace multi-dimensional synergistic regulatory effects. The compound additive provided by this invention simultaneously exerts a triple effect of "anti-stress, antibacterial, and water stabilization" during the broodstock acclimatization stage, providing a key guarantee for achieving high survival rates and stable acclimatization of broodstock.

[0046] 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 compound aquatic additive for the domestication of wild large yellow croaker broodstock, characterized in that, The product comprises the following components by weight: 0.02-0.06 parts of γ-aminobutyric acid, 3-8 parts of esterified vitamin C, 10-15 parts of broad-spectrum aquatic antibacterial agent, 20-50 parts of magnesium sulfate, and 5-10 parts of seaweed polysaccharide extract.

2. The composite water additive according to claim 1, characterized in that, The broad-spectrum aquatic antibacterial drug mentioned is enrofloxacin.

3. The application of the composite water additive as described in claim 1 or 2 in the domestication of wild large yellow croaker broodstock.

4. A method for domesticating wild large yellow croaker broodstock, characterized in that, The method includes the following steps: adding the composite aquatic additive as described in claim 1 or 2 into the aquaculture water, wherein the mass concentration of each component is 0.02-0.06 mg / L of γ-aminobutyric acid, 3-8 mg / L of esterified vitamin C, 10-15 mg / L of broad-spectrum aquatic antibacterial drug, 20-50 mg / L of magnesium sulfate, and 5-10 mg / L of seaweed polysaccharide extract.

5. The domestication method according to claim 4, characterized in that, The compound aquatic additive is applied before the parent fish are transported to the holding tank or in the initial stage after they are introduced into the water.

6. The domestication method according to claim 4, characterized in that, The composite water additive is first dissolved in a measured amount of seawater, stirred evenly, and then added to the aquaculture water.

7. The domestication method according to claim 4, characterized in that, The aquaculture water is changed every 45-50 hours, with a water replacement rate of ≥90%, and compound water additives are added again at the same time.

8. The domestication method according to claim 4, characterized in that, The aquaculture water has a temperature of 22±0.5℃, a salinity of 19-22, a pH of 8.0-8.3, and dissolved oxygen ≥5.0mg / L.

9. The domestication method according to claim 4, characterized in that, The aquaculture water is natural seawater that has been settled and filtered. It is forbidden to add strong alkaline or acidic substances and to avoid vigorous stirring.

10. The domestication method according to claim 4, characterized in that, The acclimatization process lasts for 5-7 days.