Aquatic fry breeding device

Abstract

The utility model discloses an aquatic product fry breeding device which comprises a bracket seat and a breeding groove, a filter screen assembly is fixedly installed on the inner side of the upper portion of the breeding groove, a first upper connector and a second upper connector are arranged on the outer side of the breeding groove, the first upper connector is connected with a drainage pipeline, the second upper connector is connected with a filtering circulation assembly, and the lower portion of the breeding groove is a conical bottom shell. The conical bottom shell is provided with a bottom connector and a side connector, the bottom connector is connected with a seedling emergence pipeline and a water inlet pipeline, the side connector and the bottom connector are connected through an anti-sinking pipeline, the water inlet pipeline is connected with a filtering circulation assembly, an inflation pipe with the bottom end connected with an air stone in an inserted mode is fixed in the cultivation tank, and the air stone is located at the bottom of the conical bottom shell. A drainage control valve is mounted on the drainage pipeline, a first water inlet control valve, a sterilization device and a second water inlet control valve are mounted on the water inlet pipeline, and a seedling emergence control valve is mounted on the seedling emergence pipeline. By the adoption of the device, the water changing amount can be reduced, pathogenic organisms can be killed, water quality is purified, and the survival rate of aquatic fry is increased.

Description

Technical Field

[0001] This utility model relates to the field of aquaculture technology, specifically to an aquatic seedling cultivation device. Background Technology

[0002] High requirements are placed on water quality and stability at all stages of the cultivation of crustaceans such as crabs and shrimp, shellfish, and fish fry (especially in the early, sensitive developmental stages).

[0003] Currently, shrimp and crab larvae are still raised in traditional rearing ponds, with a rearing period of 20-30 days. During this time, a large amount of uneaten feed and feces accumulate at the bottom of the pond, which cannot be removed, leading to continuous deterioration of water quality, proliferation of pathogens, and increased susceptibility to poisoning and disease. The larvae are weakened and have poor resistance, especially as they develop into juvenile shrimp and crab larvae, who tend to congregate at the bottom, causing even greater harm and low survival rates. Shrimp and crab larvae require stable water quality. While large-scale water changes can improve water quality, they disrupt this stability, hindering larval growth and survival. However, small water changes result in excessive feces and uneaten feed accumulating at the bottom, leading to excessive levels of toxic ions such as nitrite, ammonia nitrogen, and hydrogen sulfide, and promoting the growth of pathogens. For example, vibriosis has become a major cause of shrimp and crab larvae rearing failures, often resulting in significant losses. Therefore, how to reduce water changes while simultaneously purifying the water and eliminating pathogens is a crucial problem that needs to be solved.

[0004] Shellfish larvae breeding has very high requirements for water quality, with an average daily water exchange rate exceeding 100%. During the hatching stage of fertilized eggs, excess sperm and production secretions easily decompose, producing toxic ions such as ammonia nitrogen and nitrite. This not only affects the hatching rate of fertilized eggs but also has an irreversible negative impact on the health of the hatched larvae, leading to continuous mortality during subsequent rearing. This harm is significant yet difficult to control. To mitigate this adverse effect, the main approach is egg washing. For eggs with strong sinking properties, aeration can be stopped and the supernatant drained. For eggs with strong buoyancy, aeration can be stopped and the floating eggs removed. However, suspended fertilized eggs are more difficult to handle. Filtering with a screen can easily damage the fertilized eggs, affecting the hatching rate, which is difficult to implement effectively in actual production. Even for the first two types of eggs, their weak sinking and buoyancy, combined with the large volume of water in the rearing tank, makes complete stillness difficult, further complicating their handling in practice. Currently, there is no good method for washing and incubating fertilized shellfish eggs. The main approach is to control the hatching density of fertilized eggs and collect them through filter bags after the larvae have developed their original shells before transferring them to a new tank. This process often takes 18 hours or even longer, frequently causing irreversible toxicity to the larvae, resulting in weak vitality and poor resistance. These consequences will gradually manifest in subsequent production processes, affecting the final survival rate.

[0005] To improve the survival rate of crab, shrimp, shellfish and fish fry, new cultivation devices need to be designed to replace traditional cultivation ponds. Utility Model Content

[0006] To overcome the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide an aquatic seedling cultivation device that can reduce the amount of water exchange, kill pathogens, purify water quality, and improve the survival rate of aquatic seedlings.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] Aquatic seedling cultivation device includes: a support base and a cultivation trough mounted on the support base. A filter screen assembly is fixedly installed on the inner side of the upper part of the cultivation trough, and a first upper interface and a second upper interface are provided on the outer side. The first upper interface is connected to a drainage pipe, and the second upper interface is connected to a filter circulation assembly.

[0009] The lower part of the cultivation tank is configured as a conical bottom shell, which has a bottom interface and a side interface. The bottom interface is connected to a seedling outlet pipe and a water inlet pipe. The side interface and the bottom interface are connected by an anti-sinking pipe. The water inlet pipe is connected to the filtration and circulation assembly.

[0010] An air-filling pipe with an air stone inserted at its bottom is fixed inside the cultivation tank. The air stone is located at the bottom of the conical bottom shell.

[0011] The drainage pipe is equipped with a drainage control valve, the inlet pipe is equipped with a first inlet control valve, a sterilization device and a second inlet control valve, and the germination pipe is equipped with a germination control valve.

[0012] Preferably, the filtration circulation assembly includes a connecting pipe, a filter, and a pipeline pump. One end of the connecting pipe is fixedly connected to the second upper interface, and the other end is fixedly connected to the inlet pipe. The filter and the pipeline pump are installed on the connecting pipe. A first filtration circulation control valve is installed on the connecting pipe between the pipeline pump and the filter, and a second filtration circulation control valve is installed on the connecting pipe between the pipeline pump and the inlet pipe.

[0013] Preferably, the cone-shaped bottom shell of the cultivation tank has a taper of 45°.

[0014] Preferably, the filter assembly includes a filter frame and a filter. The filter frame includes an upper frustum cylinder and a lower cylindrical cylinder. The upper frustum cylinder has multiple spaced filter mounting areas, and the filter is fixedly installed in each of the filter mounting areas.

[0015] Preferably, the taper of the upper frustum of the filter frame is 45°.

[0016] Preferably, the filter frame is inserted and fixed to the upper inner side of the cultivation tank, and an insertion seat is fixed on the upper inner side wall of the cultivation tank. The insertion seat has an annular insertion groove, and the bottom of the lower cylindrical body is inserted into the annular insertion groove.

[0017] Preferably, a sealing rubber ring is provided between the annular insertion groove and the bottom of the lower cylindrical body.

[0018] Preferably, the bracket base includes an inverted conical frustum sleeve and multiple support legs, the multiple support legs being evenly distributed along the circumference of the inverted conical frustum sleeve, and the inverted conical frustum sleeve being welded and fixed to the support legs.

[0019] Preferably, the filter includes a housing and filter cotton, and the housing is provided with a sealing window.

[0020] After adopting the above technical solution, the beneficial effects of this utility model are:

[0021] The lower part of this aquatic seedling cultivation device is designed with a conical bottom shell, which greatly reduces the bottom area. Combined with the water inlet pipe, anti-sinking pipe, and air stone located at the bottom of the conical bottom shell, both newly added seawater and seawater filtered through the filtration and circulation components can enter the cultivation tank from the bottom. During aeration, air enters from the bottom, and the rising air bubbles drive the seawater upwards, ensuring that the water in and around the anti-sinking pipe is constantly circulating, preventing sedimentation at the bottom. Furthermore, the small area of ​​the conical bottom shell allows the seawater at the bottom to rise uniformly without dead zones, preventing larval feces and other pollutants from settling at the bottom and forming a bottom contamination layer, unlike traditional cultivation ponds where pollutants accumulate at the bottom.

[0022] The upwelling effect created by bottom aeration and bottom water intake ensures that the larvae always float, which is beneficial for their development and survival in aquatic seedling cultivation devices.

[0023] This aquatic seedling cultivation device adopts a bottom-inlet, top-outlet water-drainage method, ensuring that both newly added seawater and seawater filtered through the filtration and circulation components enter the cultivation tank from the bottom. This guarantees that the bottom of the cultivation tank always contains good water, while the replaced seawater is of poor quality. This avoids the problem of traditional cultivation ponds where conventional water changes (which typically involve top-outlet water drainage and replenishment) drain the upper layer of good water while the wastewater at the bottom, which is never discharged.

[0024] The pipeline pump of the filtration and circulation component makes seawater flow from top to bottom. The seawater passes through the filter cotton of the filter to remove uneaten food, feces and other impurities. The filtered seawater can then return to the cultivation tank from the bottom, thus achieving the purpose of self-circulation and self-purification of seawater. This purifies the water quality, which helps maintain the stability of the water quality in the cultivation tank and reduces the amount of water to be changed.

[0025] The filter cotton inside the filter should be replaced promptly according to the amount of impurities, generally once after each filtration cycle. The filter cotton should be removed after each filtration cycle to prevent impurities from spoiling and deteriorating. Simultaneously, the sterilization device should be activated during water circulation to kill bacteria, viruses, and other pathogenic microorganisms.

[0026] The aquatic seedling cultivation device of this invention can reduce the amount of water exchange, while killing pathogens and purifying water quality, greatly improving the survival rate of larvae.

[0027] This aquatic seedling cultivation device can be used for species or their sensitive developmental stages that require high water quality and stability, such as crabs, shrimps, shellfish, and fish seedlings at various stages of cultivation. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the aquatic seedling cultivation device of this utility model;

[0029] Figure 2 yes Figure 1 A partial cross-sectional view of a connector fixed to the upper inner wall of the incubation tank;

[0030] Figure 3 This is a schematic diagram of the annular insertion groove on the connector;

[0031] Figure 4 This is a schematic diagram of the filter assembly;

[0032] Figure 5 This is a schematic diagram of the bracket base;

[0033] Figure 6 This is a schematic diagram of a cultivation tank;

[0034] In the picture:

[0035] 1. Drainage control valve; 100. Drainage pipe; 10. Air inlet pipe; 101. Air stone; 2. First filter circulation control valve; 201. Connecting pipe; 202. Filter; 2021. Housing; 2022. Filter cotton; 2023. Sealing window; 203. Pipeline pump; 3. Second filter circulation control valve; 4. First water inlet control valve; 400. Water inlet pipe; 401. Sterilization device; 5. Second water inlet control valve 6. Emergence control valve; 600. Emergence pipe; 7. Filter assembly; 70. Filter frame; 701. Upper truncated cone cylinder; 702. Lower cylindrical cylinder; 71. Filter screen; 8. Bracket seat; 801. Inverted conical truncated cone sleeve; 802. Support leg; 9. Cultivation tank; 90. Insertion seat; 900. Conical bottom shell; 901. Annular insertion groove; 902. Sealing rubber ring; B. Anti-sinking pipe; L. Water level line. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Figure 1 The arrows inside the aquatic seedling cultivation device indicate the direction of water flow.

[0037] like Figure 1 As shown, the aquatic seedling cultivation device includes: a bracket base 8 and a cultivation trough 9 installed on the bracket base 8. A filter screen assembly 7 is fixedly installed on the inner side of the upper part of the cultivation trough 9, and a first upper interface and a second upper interface are provided on the outer side. The first upper interface is connected to a drainage pipe 100, and the second upper interface is connected to a filter circulation assembly.

[0038] The lower part of the cultivation tank 9 is set as a conical bottom shell 900. The conical bottom shell 900 is provided with a bottom interface and a side interface. The bottom interface is connected to the seedling outlet pipe 600 and the water inlet pipe 400. The side interface and the bottom interface are connected by an anti-sinking pipe B. The water inlet pipe 400 is connected to a filter circulation assembly.

[0039] An air inflator 10 with an air stone 101 inserted at its bottom is fixed inside the cultivation tank 9. The air stone 101 is located at the bottom of the conical bottom shell 900. Therefore, when inflating, air enters from the bottom, and the rising air bubbles drive the seawater to flow from bottom to top, causing the water in the anti-sinking pipe B to circulate continuously, preventing sediment from forming at the bottom and preventing the larvae from sinking. As long as air is continuously inflated into the air inflator 10, the water in the anti-sinking pipe B will continue to circulate.

[0040] A drainage control valve 1 is installed on the drainage pipe 100, a first inlet control valve 4, a sterilization device 401, and a second inlet control valve 5 are installed on the inlet pipe 400, and an germination control valve 6 is installed on the germination pipe 600. The sterilization device 401 is preferably configured as an ultraviolet sterilizer. The ultraviolet sterilizer is mainly used to kill pathogenic microorganisms such as bacteria and viruses.

[0041] The filtration and circulation assembly includes a connecting pipe 201, a filter 202, and a pipeline pump 203. One end of the connecting pipe 201 is fixedly connected to a second upper interface, and the other end is fixedly connected to an inlet water pipe 400. The filter 202 and the pipeline pump 203 are installed on the connecting pipe 201. A first filtration and circulation control valve 2 is installed on the connecting pipe 201 between the pipeline pump 203 and the filter 202, and a second filtration and circulation control valve 3 is installed on the connecting pipe 201 between the pipeline pump 203 and the inlet water pipe 400.

[0042] The inlet pipe 400 is connected to the bottom interface of the conical bottom shell 900, allowing newly added seawater and seawater filtered by the filtration and circulation components to enter the cultivation tank 9 from the bottom. This ensures that the bottom of the cultivation tank always contains good water, while the discharged seawater is of poor quality. This avoids the problem of traditional cultivation tanks where regular water changes (which typically involve draining and adding water from the top) drain the upper layer of good water while the wastewater at the bottom contaminated layer is never discharged. The contaminated layer at the bottom of traditional cultivation tanks is usually formed by the accumulation of pollutants at the bottom.

[0043] The upward flow created by bottom aeration and bottom water addition ensures that the larvae always float, which is beneficial for their development and survival in aquatic seedling cultivation devices.

[0044] To ensure the smooth rise of seawater from the bottom, an anti-sinking pipe B is connected to the side interface of the conical bottom shell 900. The air stone 101 is placed at the deepest point of the conical bottom shell 900, so that during inflation, air enters from the bottom, the rising bubbles carry the seawater upwards, thus ensuring that the water in and around the anti-sinking pipe B is constantly circulating, preventing sedimentation at the bottom. Simultaneously, it prevents larval feces and other contaminants from settling at the bottom, avoiding the formation of a bottom contamination layer, which is a common problem in traditional rearing ponds. The bottom contamination layer in traditional rearing ponds results in low larval survival rates, while the aquatic seedling rearing device of this invention significantly improves the larval survival rate.

[0045] like Figure 6 As shown, the taper of the conical bottom shell 900 of the cultivation tank 9 is preferably 45°. This makes it difficult for dirt to adhere to the side wall of the conical bottom shell 900.

[0046] like Figure 4 As shown, the filter assembly 7 includes a filter frame 70 and a filter 71. The filter frame 70 includes an upper frustum cylinder 701 and a lower cylindrical cylinder 702. The upper frustum cylinder 701 has multiple spaced filter mounting areas, and the filter 71 is fixedly installed in the filter mounting areas. Preferably, the taper of the upper frustum cylinder 701 of the filter frame 70 is 45°.

[0047] The uppermost edge of the filter screen installation area is located below the water level line L, ensuring that the upper edge of the filter screen 71 is below the water level line L to prevent larvae from splashing onto the screen above the water level and dying. The filter screen 71 is installed inside the filter screen frame 70, and different mesh sizes of silk screen are selected according to the size of the larvae. Because the upper frustum cylinder 701 of the filter screen frame 70 has a taper of 45°, larvae that come into contact with the filter screen 71 can be removed from the filter screen by the downward water flow, preventing them from agglomerating.

[0048] The filter frame 70 is inserted and fixed to the upper inner side of the cultivation tank 9. An insertion seat 90 is fixed to the upper inner wall of the cultivation tank 9. An annular insertion groove 901 is formed on the insertion seat 90, and the bottom of the lower cylindrical body 702 is inserted into the annular insertion groove 901. Figure 2 As shown, the connector 90 is fixedly connected to the inner wall of the culture tank 9 by bolts and nuts. Preferably, a sealing gasket is installed between the connector 90 and the inner wall of the culture tank 9.

[0049] A sealing rubber ring 902 is provided between the annular insertion groove 901 and the bottom of the lower cylindrical body 702.

[0050] In some embodiments, such as Figure 5 As shown, the bracket base 8 includes an inverted conical frustum sleeve 801 and multiple support legs 802. The multiple support legs 802 are evenly distributed along the circumference of the inverted conical frustum sleeve 801, and the inverted conical frustum sleeve 801 is welded and fixed to the support legs 802. Figure 5 In the middle, four support legs 802 are welded and fixed to the inverted conical frustum sleeve 801.

[0051] In some embodiments, the filter 202 includes a housing 2021 and a filter cotton 2022, and a sealing window 2023 is provided on the housing 2021. The sealing window 2023 facilitates the replacement of the filter cotton 2022.

[0052] Instructions for using aquatic seedling cultivation equipment:

[0053] (1) The seedling control valve 6 is only opened when seedlings emerge; otherwise, the valve of the seedling control valve 6 is closed.

[0054] (2) When changing the water in the aquatic seedling cultivation device: open the drain control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5, and at the same time close the first filter circulation control valve 2 and the second filter circulation control valve 3. The new seawater enters the aquatic seedling cultivation device from the bottom up through the water inlet pipe 400. The excess seawater at the top can be discharged from the drain pipe 100. After the water change is completed, close the drain control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5.

[0055] (3) When the aquatic seedling cultivation tank is self-circulating and purifying seawater: Open the first filter circulation control valve 2, the second filter circulation control valve 3, and the second water inlet control valve 5, and close the drain control valve 1 and the first water inlet control valve 4. The pipeline pump 203 makes the seawater flow from top to bottom. The seawater passes through the filter cotton 2022 of the filter 202 to remove residual feed, feces, and other impurities. The filtered seawater can then return to the cultivation tank 9 from the bottom, thus achieving the purpose of self-circulating and purifying seawater. This helps to maintain the stability of the water quality in the cultivation tank 9. The filter cotton 2022 in the filter should be replaced in time according to the amount of impurities. Generally, it should be replaced after each filtration. After filtration and circulation, the filter cotton 2022 should be removed to prevent the impurities in the filter cotton 2022 from decaying and deteriorating. When the water is circulating, the sterilization device 401 is turned on to kill bacteria, viruses, and other pathogenic microorganisms.

[0056] This aquatic seedling cultivation device can be used as an egg washing device, an incubator, or a planktonic larval culture device. Specific usage methods are as follows:

[0057] (1) Used as an egg washing device: During the incubation stage, the fertilized eggs are added to the aquatic seedling cultivation device along with seawater. The device is started and new seawater is continuously added from the bottom, ensuring that the eggs always float in the water. Moreover, the excess seawater on the upper layer carries sperm and tissue fluid from the production process and is continuously discharged from the tank, which plays a good role in washing the eggs without damaging them. After the sperm in the seawater is very low, the fertilized eggs can be transferred to the cultivation pond along with the seawater for incubation.

[0058] (2) Use as an incubator: Because the aquatic seedling cultivation device maintains good seawater quality by continuously adding new seawater and circulating and filtering seawater, the eggs and seedlings are always in a good aquatic environment. The upwelling flow formed by adding water and aeration from the bottom keeps the fertilized eggs and planktonic larvae in a suspended state, thus avoiding the eggs from accumulating at the bottom of the aquatic seedling cultivation device, which would cause them to fail to hatch normally, become deformed, or have poor vitality due to lack of oxygen and a harsh environment. At present, the hatching density of shellfish eggs in factory-style cultivation ponds is generally no more than 15 eggs / ml, and the bottom of the pond needs to be stirred once an hour, otherwise the hatching rate and larval vitality are very poor. The aquatic seedling cultivation device of this utility model can completely solve this problem. Therefore, it can not only increase the hatching density of eggs, but also increase the vitality of the larvae after hatching, and the hatching density can reach 100 eggs / ml.

[0059] (3) Used as a planktonic larvae culture device: The aquatic seedling culture device of this utility model can cultivate planktonic larvae to the bottom stage at a high density by taking full advantage of maintaining the excellent water quality of seawater 9 and making full use of the water quality of seawater 9. The cultivation density can reach 30 larvae / ml.

[0060] This aquatic seedling cultivation device can be used for species or their sensitive developmental stages that require high water quality and stability, such as crabs, shrimps, shellfish, and fish seedlings at various stages of cultivation.

[0061] This is because the larval stages of crustaceans such as crabs and shrimp, including zoea and megalopa larvae of crabs, zoea larvae, juvenile shrimp, and fish larvae, are all in a planktonic state. This planktonic stage is a critical period for larval development. At this time, the larvae are small, have high requirements for water quality and environmental stability, and have poor resistance to pathogens. The development and growth status of the larvae at this stage directly determines the quality and survival rate of the larvae. Traditional methods involve cement or plastic culture ponds, where larval excrement and uneaten feed accumulate in the water and at the bottom of the pond. This leads to a continuous increase in toxic ions such as ammonia nitrogen, nitrite, and hydrogen sulfide, which have a toxic effect on the larvae, causing them to be weak and have poor vitality, affecting metamorphosis and survival rate. In addition, the continuous increase in pathogens in the water exacerbates the larvae's sensitivity to toxic ions, making them highly susceptible to disease and death. While water changes help reduce toxic ion content during cultivation, large-scale water changes can cause stress in larvae, potentially triggering or exacerbating diseases. The aquatic seedling cultivation device of this invention effectively solves these problems.

[0062] This invention relates to an aquatic seedling cultivation device that maintains good seawater quality within the cultivation device by continuously adding and draining water to replace seawater, and by purifying seawater through self-circulation filtration, while keeping pathogens in the water at a low density level.

[0063] The process of adding and draining water aims to replace seawater and improve the water quality within the aquatic seedling cultivation device. The specific operation involves opening the drain control valve 1, the first inlet control valve 4, and the second inlet control valve 5, while simultaneously closing the first filter circulation control valve 2 and the second filter circulation control valve 3. At the same time, the ultraviolet sterilizer 401 is activated, continuously adding new seawater into the aquatic seedling cultivation device through the bottom inlet pipe. The rising new seawater pushes the old seawater from the bottom to the top of the device, where it is filtered by the filter screen 71 of the filter assembly 7 and discharged from the cultivation device through the drain pipe 100. This process improves the quality of the seawater within the device by replacing the old seawater with new seawater. This process can be repeated multiple times depending on changes in water quality.

[0064] The self-circulating purification system can maintain water quality. Open the first filter circulation control valve 2, the second filter circulation control valve 3, and the first water inlet control valve 4, and close the drain control valve 1 and the second water inlet control valve 5. Start the pipeline pump 203. The upper layer of seawater in the aquatic seedling cultivation device enters the filter 202 through the connecting pipe 201 for filtration. The filter removes residual feed and feces from the seawater. The filtered seawater enters the ultraviolet sterilizer 401 to kill all pathogens. Finally, the filtered and sterilized seawater is returned to the aquatic seedling cultivation device. This process can be carried out continuously or intermittently depending on the water quality.

[0065] Meanwhile, during the water addition and drainage, self-circulation purification, and intermittent self-circulation purification, air is continuously pumped into the air inlet pipe 10 connected to the air stone 101 at the bottom, so that the water in the anti-sinking pipe B is always in a state of flow and circulation, ensuring that the larvae and seedlings in the aquatic seedling cultivation device always float and avoid sinking to the bottom.

[0066] Because this aquatic seedling cultivation device significantly improves water quality and stability, the larvae of crustaceans such as crabs and shrimp cultivated inside it can complete the planktonic stage after 15 to 30 days of cultivation and can be sold or enter the bottom cultivation stage, with a survival rate that is more than 30% higher than that of traditional methods.

[0067] Shellfish seedlings are extremely sensitive to their environment before attachment, resulting in a high mortality rate. Therefore, it is necessary to improve existing methods for artificially cultivating shellfish seedlings to increase their survival rate. The improved method for artificially cultivating shellfish seedlings is as follows:

[0068] A method for cultivating shellfish seedlings before attachment, based on the above-mentioned aquatic seedling cultivation device, includes the following steps:

[0069] a. Artificial spawning: Mature broodstock shells are placed in an aquatic seedling cultivation device for artificial spawning induction.

[0070] During the spawning induction period, water is added and drained. Drainage control valve 1, first inlet control valve 4, and second inlet control valve 5 are opened, while the first filter circulation control valve 2 and second filter circulation control valve 3 are closed. Fresh seawater is continuously added to the aquatic seedling cultivation device, while simultaneously draining water from the drainage pipe 100. This water addition and drainage operation achieves water exchange, thereby improving water quality. While maintaining water quality, it also increases water flow intensity, thus enhancing the spawning induction effect.

[0071] Once the parent oysters begin to lay eggs and release sperm, stop adding and draining water, and close the drain control valve 1, the first water inlet control valve 4, and the second water inlet control valve 5.

[0072] About an hour later, all the parent shellfish have finished producing eggs. The parent shellfish release sperm and eggs into the water, where they combine to fertilize each other. The parent shellfish that have laid eggs are then removed from the aquatic seedling cultivation device.

[0073] b. Washing Fertilized Eggs: During the washing of fertilized eggs, water is added and drained. Open drain control valve 1, first inlet control valve 4, and second inlet control valve 5, while simultaneously closing the first filter circulation control valve 2 and the second filter circulation control valve 3. Continuously add fresh seawater to the aquatic seedling cultivation device through the bottom inlet pipe 400. The rising fresh seawater pushes the original seawater in the aquatic seedling cultivation device from the bottom to the top. The seawater, carrying failed fertilization sperm and tissue fluid from the expulsion of fertilized eggs, is filtered through the filter assembly and continuously discharged through the drain pipe 100. Simultaneously, the eggs are blocked by the filter assembly 7 and flow downstream, remaining in the aquatic seedling cultivation device.

[0074] When the seawater no longer produces foam and becomes very clear, it indicates that there are very few sperm in the water. At this point, stop adding water and draining water, and close the drain control valve 1 on the drain pipe 100 and the second water inlet control valve 5 and the first water inlet control valve 4 on the water inlet pipe in sequence to complete the egg washing process.

[0075] c. Hatching of fertilized eggs: The aquatic seedling cultivation device maintains good seawater quality by continuously adding new seawater and circulating and filtering seawater.

[0076] The first step involves adding and draining water while simultaneously sterilizing it. Water quality is improved by adding and replacing water. This is done by opening the drain control valve 1, the first inlet control valve 4, and the second inlet control valve 5, while simultaneously closing the first filter circulation control valve 2 and the second filter circulation control valve 3. The ultraviolet sterilizer 401 is then activated, continuously adding fresh seawater into the aquatic seedling cultivation device through the bottom inlet pipe. As the seawater rises, it pushes the original seawater in the aquatic seedling cultivation device from the bottom to the top. The seawater, mixed with feces and metabolic waste, is filtered through the filter screen 71 of the filter assembly 7 and continuously discharged through the drain pipe 100. This process of replacing old water with new seawater improves the quality of the seawater in the device. This process can be repeated multiple times depending on changes in water quality.

[0077] The second step involves self-circulation purification to maintain water quality. The first filter circulation control valve 2, the second filter circulation control valve 3, and the first water inlet control valve 4 are opened, while the drain control valve 1 and the second water inlet control valve 5 are closed. The pipeline pump 203 is started, and the upper layer of seawater in the aquatic seedling cultivation device enters the filter 202 through the connecting pipe 201 for filtration. The filtered seawater enters the ultraviolet sterilizer 401 to kill all pathogens. Finally, the filtered and sterilized seawater is returned to the aquatic seedling cultivation device. This process can be carried out continuously or intermittently depending on the water quality.

[0078] The third step involves continuously filling and draining water, performing self-circulation purification, and intermittent self-circulation purification. This ensures that air is continuously pumped into the air pipe 10, which is connected to the air stone 101 at the bottom. This keeps the water in the anti-sinking pipe B in a constant state of circulation, preventing the eggs from settling at the bottom of the aquatic seedling cultivation device and maintaining sufficient dissolved oxygen levels in the seawater to improve the hatching rate.

[0079] After 18 to 24 hours of incubation, all fertilized eggs hatch and develop into D-shaped larvae, entering the planktonic larval culture stage.

[0080] Because it significantly improves water quality and stability, the fertilized egg hatching density can reach 100 eggs / ml, which is 1 to 2 times higher than traditional methods;

[0081] d. Planktonic Larval Rearing: Planktonic larval rearing is the most critical period for shellfish seedling cultivation, and also the time when problems are most likely to occur. Although the planktonic period varies among different shellfish, it generally ranges from 6 to 20 days. During the planktonic larval rearing stage, mass mortality is most likely due to poor water quality and significant water quality fluctuations. This can also lead to weakened larvae, making later cultivation difficult. The main reason is that the larvae begin to feed heavily, accelerating their metabolism. This not only increases their own excretions of ammonia nitrogen and other waste products, but also leads to a large increase in feces, causing ammonia nitrogen and nitrite to accumulate in the water. Larvae are particularly sensitive to this and are prone to sinking to the bottom and dying. The conventional solution is water exchange and pond rotation (pond rotation refers to the traditional method of periodically or irregularly filtering out larvae and transferring them from one pond to another to provide a suitable aquatic environment for their development). To improve and maintain water quality, the daily water exchange rate should reach 100-300%, and to eliminate the impact of bottom sediment pollution, the ponds should be rotated every 3-5 days. While large-scale water changes improve water quality, they can lead to drastic changes. While frequent pond emptying can improve overall water and substrate conditions, it can also damage larvae, often resulting in mass larval mortality. Conversely, reducing the water exchange rate can lead to gradual deterioration of water quality and the proliferation of pathogens, causing disease outbreaks and further mortality.

[0082] In this application, an aquatic seedling cultivation device is used during the planktonic larval cultivation stage. During this period, the aquatic seedling cultivation device alternately undergoes self-circulation purification and water addition / discharge operations, while continuously filling the aeration tube at the bottom connected to the air stone with air. The self-circulation purification method for maintaining water quality is basically the same as the self-circulation purification operation during the fertilized egg hatching stage, except for the water addition / discharge time, the self-circulation purification process continues.

[0083] The self-circulating purification during the planktonic larval cultivation stage can filter out larval feces in a timely manner, preventing them from decomposing and causing a large amount of toxic ions such as ammonia nitrogen and nitrite. This keeps the seawater in the cultivation device in a good state for a long time. In addition, the ultraviolet sterilizer kills pathogenic microorganisms (including bacteria, viruses, protozoa, etc.). If the density of pathogenic microorganisms in the seawater is always kept at a very low level, it will not cause disease. Therefore, only a small amount of ammonia nitrogen and other excrement produced by the larvae themselves will accumulate in the seawater, effectively maintaining the stability of seawater quality.

[0084] The water addition and drainage operation methods in the planktonic larval stage are basically the same as those in the fertilized egg hatching stage. Since the self-circulation purification can purify the water, the water addition and drainage volume can be reduced to 30-50% during the water addition and drainage process, which further improves the water quality and maintains the stability of the water quality.

[0085] Throughout the entire larval rearing stage, air is continuously pumped into the aeration tube connected to the air stone at the bottom, ensuring the water in the anti-sinking pipe remains in a constant state of circulation. Combined with alternating self-circulating purification and water addition / discharge operations on the aquatic seedling rearing device, this ensures that contaminants never accumulate at the bottom of the device, maintaining a consistently healthy environment. Therefore, the entire rearing process can proceed without using a separate pond, eliminating larval mortality and disease caused by pond displacement. Furthermore, it keeps the larvae in suspension, guaranteeing a uniform and healthy aquatic environment. The larval rearing density can be controlled at 30–40 larvae / ml, more than double that of traditional methods.

[0086] The use of this aquatic seedling cultivation device creates the most ideal aquatic environment for artificial spawning of shellfish, washing of fertilized eggs, hatching of fertilized eggs, and cultivation of planktonic larvae. It improves the hatching rate of eggs, the quality and survival rate of larvae, and makes the juvenile shellfish after metamorphosis more healthy, vigorous, and adaptable, laying a good foundation for subsequent juvenile shellfish cultivation.

[0087] This aquatic seedling cultivation device can be used not only for the cultivation of shellfish seedlings before attachment, but also for species or their sensitive developmental stages that require high water quality and stability, such as crab, shrimp, shellfish and fish seedlings at various stages of cultivation.

Claims

1. An aquatic seedling cultivation device, characterized in that, include: The system includes a support bracket and a culture tank mounted on the support bracket. A filter assembly is fixedly installed on the inner upper part of the culture tank, and a first upper interface and a second upper interface are provided on its outer side. The first upper interface is connected to a drain pipe, and the second upper interface is connected to a filter circulation assembly. The lower part of the cultivation tank is configured as a conical bottom shell, which has a bottom interface and a side interface. The bottom interface is connected to a seedling outlet pipe and a water inlet pipe. The side interface and the bottom interface are connected by an anti-sinking pipe. The water inlet pipe is connected to the filtration and circulation assembly. An air-filling pipe with an air stone inserted at its bottom is fixed inside the cultivation tank. The air stone is located at the bottom of the conical bottom shell. The drainage pipe is equipped with a drainage control valve, the inlet pipe is equipped with a first inlet control valve, a sterilization device and a second inlet control valve, and the germination pipe is equipped with a germination control valve.

2. The aquatic seedling cultivation device as described in claim 1, characterized in that: The filtration circulation assembly includes a connecting pipe, a filter, and a pipeline pump. One end of the connecting pipe is fixedly connected to the second upper interface, and the other end is fixedly connected to the inlet pipe. The filter and the pipeline pump are installed on the connecting pipe. A first filtration circulation control valve is installed on the connecting pipe between the pipeline pump and the filter, and a second filtration circulation control valve is installed on the connecting pipe between the pipeline pump and the inlet pipe.

3. The aquatic seedling cultivation device as described in claim 2, characterized in that: The cone-shaped bottom shell of the cultivation tank has a taper of 45°.

4. The aquatic seedling cultivation device as described in claim 2, characterized in that: The filter assembly includes a filter frame and a filter. The filter frame includes an upper frustum cylinder and a lower cylindrical cylinder. The upper frustum cylinder has multiple spaced filter installation areas, and the filter is fixedly installed in each of the filter installation areas.

5. The aquatic seedling cultivation device as described in claim 4, characterized in that: The upper frustum of the filter frame has a taper of 45°.

6. The aquatic seedling cultivation device as described in claim 4, characterized in that: The filter frame is inserted and fixed to the upper inner side of the cultivation tank. An insertion seat is fixed on the upper inner side wall of the cultivation tank. An annular insertion groove is provided on the insertion seat. The bottom of the lower cylindrical body is inserted into the annular insertion groove.

7. The aquatic seedling cultivation device as described in claim 6, characterized in that: A sealing rubber ring is provided between the annular insertion groove and the bottom of the lower cylindrical body.

8. The aquatic seedling cultivation device as described in claim 6, characterized in that: The bracket base includes an inverted conical frustum sleeve and multiple support legs. The multiple support legs are evenly distributed along the circumference of the inverted conical frustum sleeve, and the inverted conical frustum sleeve is welded and fixed to the support legs.

9. The aquatic seedling cultivation device as described in claim 2, characterized in that: The filter includes a housing and filter cotton, and the housing is provided with a sealing window.

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