Aquatic fry breeding device and breeding method before attachment of shellfish fry

Abstract

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

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to an aquatic seedling cultivation device and a cultivation method for shellfish seedlings before attachment. Background Art

[0002] In the cultivation of crabs, shrimps and other crustaceans, shellfish and fish seedlings at all stages (especially in the early sensitive development stages), very high requirements are placed on water quality and water quality stability.

[0003] At present, shrimp and crab seedlings are still cultivated in traditional cultivation ponds. The cultivation period is as long as 20 to 30 days. During this period, a large amount of residual bait, feces, etc. are deposited at the bottom of the pond and cannot be removed, resulting in the continuous deterioration of water quality, the breeding of bacteria, and the easy poisoning and disease. The weak constitution and poor resistance to adversity, especially when the shrimp seedlings develop into shrimp fry and the crab seedlings develop into young crabs, all gather at the bottom of the pond, which is more harmful and causes low survival rate. The juveniles of shrimp, crab and other crustacean seedlings have high requirements for the stability of water quality. Although a large amount of water change is conducive to improving water quality, it destroys the stability of water quality and is not conducive to the growth and survival of the juveniles. However, if the amount of water change is small, it will lead to a large amount of fecal residual bait, which will be deposited at the bottom of the cultivation, causing toxic ions such as nitrite, ammonia nitrogen, and hydrogen sulfide to exceed the standard, and it is easy to breed a large number of pathogens. For example, vibriosis has become an important reason for the failure of shrimp and crab seedling cultivation, often causing heavy losses. Therefore, how to reduce the amount of water change while purifying the water quality and killing pathogens is an important problem that needs to be solved.

[0004] Shellfish seed breeding has very high requirements for water quality, and its average daily water exchange volume reaches more than 100%. During the fertilized egg hatching stage, excess sperm and production secretions are very easy to deteriorate and produce toxic ions such as ammonia nitrogen and nitrite, which not only affect the hatching rate of fertilized eggs, but also have an adverse effect on the physique of the hatched larvae that is difficult to change. They will continue to die in subsequent cultivation, which is extremely harmful but difficult to deal with. In order to change this adverse consequence, the main egg washing measures are taken. For eggs with strong sinking properties, the method of discharging the upper clear water after stopping the gas can be adopted; for eggs with strong buoyancy, the method of stopping the gas and stilling, and then taking out the floating eggs can be adopted; while for suspended fertilized eggs, it is more difficult to handle. If filtered with a filter, it is very easy to damage the fertilized eggs and affect the hatching rate, which is difficult to do well in actual production. Even the first two types of eggs, because they are not strong in sinking and buoyancy, the water body of the cultivation pool is large and it is difficult to be completely still, so it is also difficult to handle in actual operation. There is no good method for washing and incubating fertilized shellfish eggs. The main method is to control the hatching density of fertilized eggs. After the larvae develop their primary shells, they are collected by filtering through filter bags and placed in new ponds. This process often takes 18 hours or even longer, often causing irreversible poisoning to the larvae, resulting in weak vitality and poor resistance, which will gradually manifest in the subsequent production process and affect the final survival rate.

[0005] In order to improve the survival rate of crab, shrimp, shellfish and fish seedlings, new breeding equipment needs to be designed to replace traditional breeding ponds. At the same time, shellfish seedlings are extremely sensitive to the environment before they attach, and the mortality rate is high. Therefore, it is necessary to improve the existing methods of artificially breeding shellfish seedlings to improve the survival rate of shellfish seedlings. Summary of the invention

[0006] In order to overcome the above-mentioned deficiencies of the prior art, the first technical problem to be solved by the present invention is to provide an aquatic seedling cultivation device that can reduce the amount of water change, while killing pathogens, purifying water quality, and improving the survival rate of aquatic seedlings.

[0007] The second technical problem to be solved by the present invention is to provide a method for cultivating shellfish seedlings before attachment, which can improve the survival rate of shellfish seedlings.

[0008] In order to solve the above-mentioned first technical problem, the present invention adopts the following technical solution:

[0009] An aquatic seedling cultivation device comprises: a bracket seat and a cultivation tank installed on the bracket seat, a filter assembly is fixedly installed on the inner side of the upper part of the cultivation tank, and a first upper interface and a second upper interface are arranged on the outer side, the first upper interface is connected to a drainage pipe, and the second upper interface is connected to a filtering circulation assembly.

[0010] The lower part of the cultivation tank is set as a conical bottom shell, and the conical bottom shell is provided with a bottom interface and a side interface. The bottom interface is connected with a seedling emergence pipeline and a water inlet pipeline. The side interface and the bottom interface are connected through an anti-sinking pipeline. The water inlet pipeline is connected to the filtering circulation component.

[0011] An air-filled tube with an air stone plugged into the bottom end is fixed in the cultivation tank, and the air stone is located at the bottom of the conical bottom shell.

[0012] The drainage pipe is equipped with a drainage control valve, the water inlet pipe is equipped with a first water inlet control valve, a sterilizing device and a second water inlet control valve, and the seedling emergence pipe is equipped with a seedling emergence control valve.

[0013] Preferably: the filtration circulation component 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 water 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 water inlet pipe.

[0014] Preferably, the conical bottom shell of the cultivation tank has a taper of 45°.

[0015] Preferably, the filter assembly comprises a filter frame and a filter, the filter frame comprises an upper conical cylinder and a lower cylindrical cylinder, a plurality of spaced filter installation areas are provided on the upper conical cylinder, and the filter is fixedly installed at the filter installation area.

[0016] Preferably, the taper of the upper frustum cylinder of the filter frame is 45°.

[0017] Preferably: the filter frame is plugged and fixed on the upper inner side of the cultivation tank, a plug-in seat is fixed on the upper inner wall of the cultivation tank, an annular plug-in groove is provided on the plug-in seat, and the bottom of the lower cylindrical body is inserted into the annular plug-in groove.

[0018] Preferably, a sealing rubber ring is provided between the annular plug-in groove and the bottom of the lower cylindrical body.

[0019] Preferably, the bracket seat comprises an inverted conical truncated cone sleeve and a plurality of supporting legs, the plurality of supporting legs are evenly distributed along the circumference of the inverted conical truncated cone sleeve, and the inverted conical truncated cone sleeve is fixed to the supporting legs by welding.

[0020] Preferably, the filter comprises a shell and filter cotton, and a sealing window is provided on the shell.

[0021] To solve the above second technical problem, the present invention adopts the following technical solution:

[0022] A method for cultivating shellfish seedlings before attachment, based on the above-mentioned aquatic seedling cultivation device, the method comprises the following steps:

[0023] a. Artificial induction of spawning: placing the parent shellfish with mature gonads into the aquatic seed breeding device for artificial induction of spawning,

[0024] During the induced labor period, water is added and drained, the drainage control valve, the first water inlet control valve and the second water inlet control valve are opened, and the first filter circulation control valve and the second filter circulation control valve are closed at the same time, and new seawater is continuously added to the aquatic seedling cultivation device, and at the same time, water is continuously drained out from the drainage pipe.

[0025] When the parent shellfish starts to lay eggs and ejaculate, stop adding water and draining water, and close the drainage control valve, the first water inlet control valve and the second water inlet control valve;

[0026] After a period of time, the parent shellfish have all completed production, and the parent shellfish release sperm and eggs into the water. The sperm and eggs combine with each other to complete fertilization, and the parent shellfish after spawning are taken out of the aquatic seed cultivation device;

[0027] b. Washing fertilized eggs: When washing fertilized eggs, water is added and drained. The drainage control valve, the first water inlet control valve and the second water inlet control valve are opened, and the first filter circulation control valve and the second filter circulation control valve are closed at the same time. New seawater is continuously added to the aquatic seedling cultivation device from the bottom water inlet pipe. The new seawater rises and pushes the original seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer. The seawater carries a large amount of excess sperm after fertilization and tissue fluid when fertilized eggs are discharged. After being filtered by the filter assembly, the seawater is continuously discharged from the drainage pipe. At the same time, the eggs are blocked by the filter assembly and flow downward with the water and remain in the aquatic seedling cultivation device.

[0028] When there is no more foam in the seawater and the seawater is very clear, it means that there are very few sperm in the water. At this time, stop adding water and draining water, and close the drainage control valve, the second water inlet control valve and the first water inlet control valve in sequence to complete the egg washing process;

[0029] c. Fertilized egg hatching: the first step is to add water, drain water and sterilize at the same time, improve water quality by adding water and changing water, open the drainage control valve, the first water inlet control valve and the second water inlet control valve, and close the first filter circulation control valve and the second filter circulation control valve at the same time, and start the ultraviolet sterilizer, and continuously add new seawater from the bottom water inlet pipe to the aquatic seedling cultivation device. The rising seawater pushes the original seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer, and the seawater mixed with organic particles and metabolic products produced by the death and rupture of eggs is filtered by the filter assembly and continuously discharged from the drainage pipe. This process can be started multiple times according to the changes in water quality;

[0030] The second step is to perform self-circulation purification, open the first filter circulation control valve, the second filter circulation control valve and the first water inlet control valve, and close the drainage control valve and the second water inlet control valve, start the pipeline pump, and the upper seawater in the aquatic seedling cultivation device enters the filter through the connecting pipeline for filtration, and the filtered seawater enters the ultraviolet sterilizer to kill all pathogens, and finally the filtered and sterilized seawater returns to the aquatic seedling cultivation device. This process can be carried out continuously or intermittently according to the water quality conditions;

[0031] The third step is to inflate the air pipe with the air stone plugged into the bottom during the water addition and drainage period, the self-circulation purification period, and the self-circulation purification interruption period, so that the water in the anti-sinking pipe is always in a flowing circulation state, so that the eggs will not settle at the bottom of the aquatic seedling cultivation device, so as to improve the hatching rate.

[0032] After a period of incubation, all fertilized eggs hatched and developed into D-shaped larvae, entering the planktonic larvae culture stage;

[0033] d. Cultivation of planktonic larvae: During the cultivation of planktonic larvae, the aquatic seed cultivation device is subjected to alternating self-circulation purification and water addition and drainage operations, and the air tube connected to the air stone at the bottom is inflated all the time. The cultivation time is 6 to 20 days, and the density of planktonic larvae cultivation can be controlled at 30 to 40 larvae per milliliter.

[0034] After adopting the above technical solution, the beneficial effects of the present invention are:

[0035] The lower part of the aquatic seedling cultivation device of the present invention is arranged as a conical bottom shell, which greatly reduces the area of ​​the bottom. In addition, a water inlet pipe, an anti-sinking pipe and an air stone are arranged at the bottom of the conical bottom shell, so that the newly added seawater from the water inlet pipe and the seawater filtered through the filtering circulation component can enter the cultivation tank from the bottom. When inflated, the air enters from the bottom, and the bubbles float up to drive the seawater to flow from bottom to top, so that the water in the anti-sinking pipe and its vicinity is always in a circulating flow, avoiding the formation of precipitation at the bottom. In addition, the bottom area of ​​the conical bottom shell of the cultivation device is relatively small, so that the seawater at the bottom of the conical bottom shell rises as a whole without leaving dead corners, avoiding the sedimentation of pollutants such as larval feces at the bottom, and preventing the formation of a bottom pollution layer, thereby avoiding the formation of a bottom pollution layer formed by the collection of pollutants at the bottom in traditional cultivation pools.

[0036] The upward current formed by the bottom inflation and the water inlet makes the larvae float up forever. The effect of the larvae floating up forever in the aquatic seed breeding device is beneficial to the development and survival of the larvae.

[0037] The aquatic seedling cultivation device of the present invention adopts the method of bottom water intake and top water discharge, so that the newly added seawater and the seawater filtered by the filtering circulation component can enter the cultivation tank from the bottom, thereby ensuring that the bottom of the cultivation tank is always good water and the replaced seawater is bad. It avoids the situation that when the conventional cultivation pool adopts conventional water exchange (the conventional water exchange method generally drains water and adds water from the top), the upper layer of good water is discharged while the sewage at the bottom pollution layer can never be discharged.

[0038] The pipeline pump of the filtration circulation component makes the seawater flow from top to bottom. The seawater passes through the filter cotton to filter out the remaining bait, feces and other impurities. The filtered seawater can return to the breeding tank from the bottom of the breeding tank, thereby achieving the purpose of self-circulation and self-purification of seawater, purifying the water quality. This is conducive to maintaining the stability of the water quality in the breeding tank and can reduce the amount of water change.

[0039] The filter cotton in the filter should be replaced in time according to the impurities. Generally, it should be replaced every time you filter. The filter cotton should be taken out after the filter cycle to prevent the impurities in the filter cotton from spoiling. At the same time, when the water circulates, the sterilization device should be turned on to kill bacteria, viruses and other pathogenic microorganisms.

[0040] The aquatic seedling cultivation device of the present invention can reduce the amount of water change, kill pathogenic organisms, purify water quality, and greatly improve the survival rate of larvae.

[0041] The aquatic seedling cultivation device of the present invention can be used for species with high requirements for water quality and high requirements for water quality stability or their sensitive development stages, such as crabs, shrimps, shellfish and various stages of fish seed cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of the aquatic seed cultivation device of the present invention;

[0043] Figure 2 yes Figure 1 A partial cross-sectional schematic diagram showing a plug-in socket fixed on the upper inner wall of the middle cultivation tank;

[0044] Figure 3 is a schematic diagram of an annular plug-in groove on a plug socket;

[0045] Figure 4 is a schematic diagram of the filter assembly;

[0046] Figure 5 is a schematic diagram of the bracket seat;

[0047] Figure 6 It is a schematic diagram of the cultivation tank;

[0048] In the figure:

[0049] 1. Drainage control valve; 100, drainage pipe; 10, inflation 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 Valve; 6. Seedling control valve; 600. Seedling pipeline; 7. Filter assembly; 70. Filter frame; 701. Upper conical cylinder; 702. Lower cylindrical cylinder; 71. Filter; 8. Bracket seat; 801. Inverted conical conical sleeve; 802. Support leg; 9. Cultivation tank; 90. Plug-in seat; 900. Conical bottom shell; 901. Annular plug-in groove; 902. Sealing rubber ring; B. Anti-sinking pipeline; L. Water level line. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below with reference to the accompanying drawings and embodiments. Figure 1 The arrow inside the aquatic seedling cultivation device indicates the direction of water flow.

[0051] like Figure 1As shown, the aquatic seedling cultivation device comprises: a bracket seat 8 and a cultivation tank 9 installed on the bracket seat 8, a filter assembly 7 is fixedly installed on the inner side of the upper part of the cultivation tank 9, and a first upper interface and a second upper interface are arranged on the outer side, the first upper interface is connected to a drainage pipe 100, and the second upper interface is connected to a filtering circulation assembly.

[0052] The lower part of the cultivation tank 9 is set as a conical bottom shell 900, and the conical bottom shell 900 is provided with a bottom interface and a side interface. The bottom interface is connected to the seedling pipeline 600 and the water inlet pipeline 400. The side interface and the bottom interface are connected through an anti-sinking pipeline B. The water inlet pipeline 400 is connected to the filtering circulation component.

[0053] The cultivation tank 9 is fixed with an air tube 10 with an air stone 101 inserted at the bottom. 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 bubbles float up to drive the seawater to flow from bottom to top, driving the water in the anti-sinking pipe B to circulate continuously, thereby preventing the formation of sediment at the bottom and preventing the larvae from sinking to the bottom. As long as the air tube 10 is inflated, the water in the anti-sinking pipe B will circulate continuously.

[0054] A drainage control valve 1 is installed on the drainage pipe 100, a first water inlet control valve 4, a sterilizing device 401 and a second water inlet control valve 5 are installed on the water inlet pipe 400, and a seedling emergence control valve 6 is installed on the emergence pipe 600. Among them, the sterilizing device 401 is preferably set as an ultraviolet sterilizer. The ultraviolet sterilizer is mainly used to kill pathogenic microorganisms such as bacteria and viruses.

[0055] The filtration circulation component includes a connecting pipe 201, a filter 202 and a pipeline pump 203. One end of the connecting pipe 201 is fixedly connected to the second upper interface, and the other end is fixedly connected to the water inlet pipe 400. The filter 202 and the pipeline pump 203 are installed on the connecting pipe 201. A first filtration circulation control valve 2 is installed on the connecting pipe 201 between the pipeline pump 203 and the filter 202, and a second filtration circulation control valve 3 is installed on the connecting pipe 201 between the pipeline pump 203 and the water inlet pipe 400.

[0056] The water inlet pipe 400 is connected to the bottom interface of the conical bottom shell 900, so that the newly added seawater and the seawater filtered by the filtering circulation component can enter the cultivation tank 9 from the bottom, thereby ensuring that the bottom of the cultivation tank is always good water and the discharged seawater is bad. This avoids the situation that when the conventional cultivation tank adopts conventional water exchange (the conventional water exchange method generally drains water and adds water from the top), the upper layer of good water is discharged while the sewage at the bottom pollution layer can never be discharged. The bottom pollution layer of the conventional cultivation tank is usually formed by the accumulation of pollutants at the bottom.

[0057] The upward current formed by aeration and water addition from the bottom makes the larvae float up forever. The effect of the larvae floating up forever in the aquatic seed breeding device is beneficial to the development and survival of the larvae.

[0058] In order to make the bottom seawater rise smoothly, 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 part of the conical bottom shell 900, so that when it is inflated, the air enters from the bottom, and the bubbles float up to drive the seawater to flow from bottom to top, so that the water in and near the anti-sinking pipe B is always in a circulating flow, avoiding the formation of sediment at the bottom. At the same time, it also avoids the contaminants such as larval feces from settling at the bottom, and does not form a bottom pollution layer, avoiding the bottom pollution layer formed by the contaminants gathering at the bottom in the traditional breeding pool. The bottom pollution layer of the traditional breeding pool makes the survival rate of the larvae low, while the aquatic seed breeding device of the present invention greatly improves the survival rate of the larvae.

[0059] like Figure 6 As shown, the conical bottom shell 900 of the cultivation tank 9 is preferably tapered at 45° so that dirt is not easily attached to the side wall of the conical bottom shell 900 .

[0060] 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 truncated cone body 701 and a lower cylindrical body 702. The upper truncated cone body 701 is provided with a plurality of spaced filter installation areas, and the filter 71 is fixedly installed at the filter installation area. Preferably, the taper of the upper truncated cone body 701 of the filter frame 70 is 45°.

[0061] The uppermost edge of the filter installation area is located below the water level L, ensuring that the upper edge of the filter 71 is below the water level L to prevent the larvae from splashing onto the net above the water level and dying. The filter 71 is installed inside the filter frame 70, and screens of different mesh sizes are selected according to the size of the larvae. Since the taper of the upper truncated cone cylinder 701 of the filter frame 70 is 45°, the larvae that hit the filter 71 can be separated from the filter with the downward water flow to avoid aggregation.

[0062] The filter frame 70 is plugged and fixed on the upper inner side of the cultivation tank 9. A plug-in seat 90 is fixed on the upper inner side wall of the cultivation tank 9. The plug-in seat 90 is provided with an annular plug-in groove 901. The bottom of the lower cylindrical body 702 is inserted into the annular plug-in groove 901. Figure 2 As shown, the socket 90 is fixedly connected to the inner side wall of the cultivation tank 9 by bolts and nuts. Preferably, a sealing gasket is installed between the socket 90 and the inner side wall of the cultivation tank 9.

[0063] A sealing rubber ring 902 is provided between the annular plug-in groove 901 and the bottom of the lower cylindrical body 702 .

[0064] In some embodiments, Figure 5As shown, the bracket seat 8 includes an inverted conical truncated cone sleeve 801 and a plurality of supporting legs 802 . The plurality of supporting legs 802 are evenly distributed along the circumference of the inverted conical truncated cone sleeve 801 . The inverted conical truncated cone sleeve 801 and the supporting legs 802 are welded and fixed. Figure 5 In the figure, four supporting legs 802 are provided and are welded and fixed to the inverted conical truncated cone sleeve 801.

[0065] In some embodiments, the filter 202 includes a housing 2021 and filter cotton 2022, and a sealing window 2023 is provided on the housing 2021. The provision of the sealing window 2023 facilitates the replacement of the filter cotton 2022.

[0066] Method of using aquatic seed cultivation device:

[0067] (1) The emergence control valve 6 is opened only when the seedlings emerge, and the emergence control valve 6 is in a closed state in other states.

[0068] (2) When changing the water in the aquatic seedling cultivation device: open the drainage control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5. At the same time, close the first filtration circulation control valve 2 and the second filtration circulation control valve 3. New seawater enters the aquatic seedling cultivation device from the bottom to the top through the water inlet pipe 400. The excess seawater in the upper part can be discharged from the drainage pipe 100. After the water change is completed, close the drainage control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5.

[0069] (3) When the aquatic seedling cultivation device purifies seawater by self-circulation: open the first filter circulation control valve 2, the second filter circulation control valve 3 and the second water inlet control valve 5, close the drainage control valve 1 and the first water inlet control valve 4, and the pipeline pump 203 allows the seawater to flow from top to bottom. The seawater passes through the filter cotton 2022 of the filter 202 to filter out the remaining bait, feces and other impurities. The filtered seawater can return to the cultivation tank 9 from the bottom of the cultivation tank 9, thereby achieving the purpose of self-circulation and purification of seawater, which is conducive to maintaining the stability of the water quality in the cultivation tank 9. The filter cotton 2022 in the filter is replaced in time according to the impurity situation, generally replaced once every filtration, and the filter cotton 2022 is taken out after the filtration cycle to prevent the impurities in the filter cotton 2022 from rotting and deteriorating. When the water circulates, the sterilization device 401 is turned on to kill bacteria, viruses and other pathogenic microorganisms.

[0070] The aquatic seedling cultivation device of the present invention can be used as an egg washer, an incubator, or a planktonic larvae culture device. The specific use method is as follows:

[0071] (1) Used as an egg washer: During the incubation stage, the fertilized eggs are added together with seawater to the aquatic seedling cultivation device, the equipment is started, and new seawater is continuously added from the bottom to ensure that the eggs always float in the water. In addition, the extra seawater on the upper layer carries sperm and tissue fluid during production and is continuously discharged from the water tank, which plays a good egg washing role while ensuring that the eggs are not damaged. When there are very few sperm in the seawater, the fertilized eggs can be moved together with the seawater into the cultivation pool for incubation.

[0072] (2) Use as an incubator: Since the aquatic seedling cultivation device always maintains good seawater quality by continuously adding new seawater and circulating filtered seawater, the eggs and seedlings are always in a good water environment; the upwelling formed by adding water and aeration from the bottom makes the fertilized eggs and planktonic larvae always in a suspended state, thus avoiding the eggs from gathering at the bottom of the aquatic seedling cultivation device, which causes the eggs to be unable to hatch normally, deformed or have poor vitality due to lack of oxygen and adverse environment. At present, the hatching density of shellfish eggs in factory-based cultivation ponds generally does not exceed 15 eggs / ml, and the pond bottom needs to be stirred once every hour, otherwise the hatching rate and larval vitality are very poor. The aquatic seedling cultivation device of the present invention can completely solve this problem, so that not only can the hatching density of eggs be increased, but also the vitality of the hatched larvae can be increased, and the hatching density can reach 100 eggs / ml.

[0073] (3) Used as a planktonic larvae culture device: Since the aquatic seedling cultivation device of the present invention takes in water from the bottom of the cultivation tank 9 and fully utilizes the great advantage of maintaining excellent seawater quality, it can cultivate planktonic larvae to the bottom stage at a high density, and the cultivation density can reach 30 / ml.

[0074] The aquatic seedling cultivation device of the present invention can be used for species with high requirements for water quality and high requirements for water quality stability or their sensitive development stages, such as crabs, shrimps, shellfish and various stages of fish seed cultivation.

[0075] This is because the cultivation of crustacean seedlings such as crabs and shrimps, the zoan larvae and megalopa of crabs, the zoan larvae, shrimp larvae, shrimp larvae, and fish larvae are all in a planktonic state, which is also the key period for their seedling cultivation. At this time, the larvae are small, have high requirements for water quality and environmental stability, and have poor resistance to pathogenic microorganisms. The development and growth state of the larvae at this stage directly determines the quality and survival rate of the seedlings. The traditional method is to carry out in cement or plastic culture pools. The excrement of the larvae and the residual bait and feces continue to accumulate in the water and at the bottom of the pool, resulting in the continuous increase of toxic ions such as ammonia nitrogen, nitrite, and hydrogen sulfide in the water and at the bottom of the pool, which has a toxic effect on the larvae, causing the larvae to be weak and have poor vitality, affecting metamorphosis and survival rate; in addition, the pathogenic microorganisms in the water continue to increase, aggravating the sensitivity of the larvae to toxic ions, making the larvae very easy to get sick and die. During the cultivation process, although changing water is beneficial to reducing the content of toxic ions, a large amount of water change will cause stress reaction in the larvae, which will in turn trigger or aggravate the occurrence of diseases. The aquatic seed cultivation device of the present invention can effectively solve these problems when cultivating.

[0076] The aquatic seedling cultivation device of the present invention replaces seawater by continuously adding water and draining water, and purifies seawater by self-circulating filtration to always maintain good seawater quality in the cultivation device and keep pathogenic bacteria in the water at a low density level.

[0077] The purpose of replacing seawater is achieved by adding water and draining water to improve the water quality in the aquatic seedling cultivation device. The specific operation of adding water and draining water is: open the drainage control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5, and close the first filter circulation control valve 2 and the second filter circulation control valve 3. At the same time, start the ultraviolet sterilizer 401, and continuously add new seawater from the bottom water inlet pipe to the aquatic seedling cultivation device. The new seawater rises and pushes the original old seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer. After being filtered by the filter 71 of the filter assembly 7, it is discharged from the cultivation device from the drainage pipe 100, thereby improving the seawater quality in the device by replacing the old seawater with new seawater. This process can be started multiple times according to the changes in water quality.

[0078] The purpose of maintaining water quality can be achieved by using self-circulation purification. The first filtering circulation control valve 2, the second filtering circulation control valve 3 and the first water inlet control valve 4 are opened, and the drainage control valve 1 and the second water inlet control valve 5 are closed. The pipeline pump 203 is started, and the upper seawater in the aquatic seedling cultivation device enters the filter 202 through the connecting pipeline 201 for filtration, and the residual bait and feces in the seawater are filtered out. The filtered seawater enters the ultraviolet sterilizer 401 to kill all pathogens, and finally the filtered and sterilized seawater returns to the aquatic seedling cultivation device. This process can be carried out continuously or intermittently according to the water quality conditions;

[0079] At the same time, during the water addition and drainage, self-circulation purification and self-circulation purification interruption, air is continuously inflated into the inflation tube 10 with the air stone 101 inserted at the bottom, so that the water in the anti-sinking pipe B is always in a flowing circulation state, ensuring that the larvae and seedlings in the aquatic seedling cultivation device always float up and avoid sinking to the bottom.

[0080] The aquatic seedling cultivation device of the present invention significantly improves the water quality and its stability. After 15 to 30 days of cultivation, the larvae of crustaceans such as crabs and shrimps cultivated therein can end the floating stage and can be sold or enter the bottom cultivation stage. The survival rate is increased by more than 30% compared with the traditional method.

[0081] The present invention discloses a method for cultivating shellfish seedlings before attachment. Based on the above-mentioned aquatic seedling cultivation device, the method comprises the following steps:

[0082] a. Artificial induction of spawning: placing the parent shellfish with mature gonads into the aquatic seed breeding device for artificial induction of spawning,

[0083] During the period of inducing labor, water is added and drained. The drainage control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5 are opened, and the first filter circulation control valve 2 and the second filter circulation control valve 3 are closed at the same time. New seawater is continuously added to the aquatic seedling cultivation device, and at the same time, water is continuously drained out from the drainage pipe 100. The purpose of water change is achieved through the above-mentioned water addition and drainage operations, thereby improving the water quality. While maintaining the water quality, the water flow intensity is increased, which plays a role in enhancing the inducing labor.

[0084] When the parent shellfish begins to lay eggs and ejaculate, stop adding water 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;

[0085] After about 1 hour, all the broodstock have finished giving birth. The broodstock release sperm and eggs into the water. The sperm and eggs combine with each other to complete fertilization. The broodstock after spawning are taken out of the aquatic seed cultivation device;

[0086] b. Washing fertilized eggs: When washing fertilized eggs, water is added and drained. The drainage control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5 are opened, and the first filter circulation control valve 2 and the second filter circulation control valve 3 are closed at the same time. New seawater is continuously added to the aquatic seedling cultivation device from the bottom water inlet pipe 400. The new seawater rises and pushes the original seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer. The seawater carries the sperm that failed to fertilize and the tissue fluid when the sperm is discharged from the egg after being filtered by the filter assembly, and is continuously discharged from the drainage pipe 100. At the same time, the eggs are blocked by the filter assembly 7 and flow downward with the water and remain in the aquatic seedling cultivation device.

[0087] When there is no more foam in the seawater and it is very clear, it means that there are very few sperm in the water. At this time, stop adding water and draining water, and close the drainage control valve 1 on the drainage 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;

[0088] c. Fertilized egg hatching: The aquatic seedling cultivation device always maintains good seawater quality in the device by continuously adding new seawater and circulating filtered seawater.

[0089] The first step is to add water, drain water and sterilize at the same time, and improve the water quality by adding water and changing water. The drainage control valve 1, the first water inlet control valve 4 and the second water inlet control valve 5 are opened, and the first filter circulation control valve 2 and the second filter circulation control valve 3 are closed at the same time, and the ultraviolet sterilizer 401 is started, and new seawater is continuously added to the aquatic seedling cultivation device from the bottom water inlet pipe. The rising seawater pushes the original seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer. The seawater mixed with feces and metabolic products is filtered by the filter 71 of the filter assembly 7 and continuously discharged from the drainage pipe 100; the feces and metabolic products (such as harmful substances) are discharged, thereby improving the quality of seawater in the device by replacing old water with new seawater. This process can be started multiple times according to the change of water quality;

[0090] The second step is to perform 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, and the drainage control valve 1 and the second water inlet control valve 5 are closed. The pipeline pump 203 is started, and the upper 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 returns to the aquatic seedling cultivation device. This process can be carried out continuously or intermittently according to the water quality.

[0091] The third step is to inflate the air pipe 10 connected to the air stone 101 at the bottom during the water addition and drainage, self-circulation purification and self-circulation purification interruption, so that the water in the anti-sinking pipe B is always in a flowing circulation state, so that the eggs will not settle at the bottom of the aquatic seedling cultivation device, and maintain sufficient dissolved oxygen content in the seawater to improve the hatching rate.

[0092] After 18 to 24 hours of incubation, all fertilized eggs hatch and develop into D-shaped larvae, entering the planktonic larval culture stage;

[0093] Because the water quality and stability have been significantly improved, the hatching density of fertilized eggs can reach 100 eggs / ml, which is 1 to 2 times higher than the traditional method;

[0094] d. Planktonic larvae cultivation: Planktonic larvae cultivation is the most critical period for shellfish seed cultivation and is also the time when problems are most likely to occur. Although the planktonic time of different shellfish is different, it is generally 6 to 20 days. The planktonic larvae cultivation stage is most likely to cause a large number of deaths due to poor water quality and large changes in water quality, which will also cause physical weakness and make it difficult to cultivate in the later stage. The main reason is that the larvae begin to eat a lot and their metabolism speeds up. Not only does their own excretion of ammonia nitrogen and other excretions increase, but also the excretion of feces increases a lot, resulting in the continuous accumulation of ammonia nitrogen and nitrite in the water. The larvae are particularly sensitive to this and are easily caused to sink to the bottom and die. The conventional solution is to change water and turn the pond (the example pond refers to the conventional method of filtering out the larvae from one pond and moving them to another pond regularly or irregularly during traditional shellfish seed cultivation to provide a water environment suitable for the larvae to develop). In order to improve and maintain water quality, the daily water change volume reaches 100-300%, and in order to eliminate the impact of pond bottom sediment pollution, the pond is turned every 3-5 days. Although large-scale water changes can improve water quality, they can lead to dramatic changes in water quality. Although pond inversion can improve water quality and bottom environmental conditions overall, it can also cause damage to larvae. Large-scale water changes and frequent pond inversions often cause large-scale larval deaths. If the amount of water changes is reduced, the water quality will gradually deteriorate and a large number of pathogens will breed, leading to diseases and causing large-scale deaths.

[0095] The present application uses an aquatic seedling cultivation device in the planktonic larvae cultivation stage, during which the aquatic seedling cultivation device is alternately subjected to self-circulation purification and water addition and drainage operations, and air is continuously inflated into the inflation tube with the air stone plugged into the bottom end, wherein the self-circulation purification and water quality maintenance operation method is basically the same as the self-circulation purification operation in the above-mentioned fertilized egg hatching stage, except for the time of water addition and drainage, the self-circulation purification process is continuously carried out.

[0096] The self-circulating purification in the planktonic larvae cultivation stage can filter out the larval feces in time, so that it will not decompose and cause the large-scale production of toxic ions such as ammonia nitrogen and nitrite, so that the seawater in the cultivation device can maintain a good treatment state for a long time. In addition, the ultraviolet disinfector circulates and kills pathogenic microorganisms (including bacteria, viruses, protozoa, etc.). If the density of pathogenic microorganisms in seawater is always at an extremely low state, it will not cause diseases. Therefore, only a small amount of excrement such as ammonia nitrogen produced by the larvae themselves will accumulate in the seawater, effectively maintaining the stability of seawater quality;

[0097] The water adding and water draining operation method in the planktonic larvae cultivation stage is basically the same as the water adding and water draining operation method in the fertilized egg hatching stage. Since the self-circulating purification can purify the water quality, the amount of water added and water exchanged can be reduced to 30-50% during the water adding and water draining process, which further improves the water quality and maintains the stability of the water quality.

[0098] During the whole stage of the cultivation of planktonic larvae, the air is continuously inflated into the air pipe with the air stone inserted at the bottom, so that the water in the anti-sinking pipe is always in a flowing circulation state. In addition, the aquatic seedling cultivation device is alternately self-circulating and purified and water is added and drained. On the one hand, it is ensured that no pollutants are deposited at the bottom of the aquatic seedling cultivation device, and the bottom environment is always maintained in a good state. Therefore, the whole cultivation process does not need to use the case pool. The death of larvae and the occurrence of diseases caused by the damage of the inverted pool are eliminated. On the other hand, the planktonic larvae are always kept in a suspended state, ensuring that the planktonic larvae are always in a uniform and good water environment. The density of planktonic larvae cultivation can be controlled at 30-40 / ml, which is more than 1 times higher than that of the traditional method.

[0099] The use of the aquatic seed cultivation device of the present invention creates the most ideal water environment for artificial induction of shellfish spawning, washing of fertilized eggs, hatching of fertilized eggs and cultivation of planktonic larvae, improves the hatching rate of eggs, improves the quality and survival rate of larvae, makes the juvenile shellfish after metamorphosis and attachment healthier and more energetic, and has stronger adaptability, laying a good foundation for subsequent juvenile shellfish cultivation.

[0100] The aquatic seedling cultivation device of the present invention can not only be used for the cultivation of the above-mentioned shellfish seedlings before attachment, but can also be used for species with high requirements for water quality and high requirements for water quality stability or their sensitive developmental stages, such as various stages of crab, shrimp, shellfish and fish seed cultivation.

Claims

1. An aquatic seedling cultivation device, characterized in that: include: A bracket seat and a cultivation tank mounted on the bracket seat, wherein a filter assembly is fixedly mounted on the inner side of the upper part of the cultivation tank, and a first upper interface and a second upper interface are arranged on the outer side, wherein the first upper interface is connected to a drainage pipe, and the second upper interface is connected to a filtering circulation assembly, The lower part of the cultivation tank is set as a conical bottom shell, and the conical bottom shell is provided with a bottom interface and a side interface. The bottom interface is connected with a seedling emergence pipeline and a water inlet pipeline. The side interface and the bottom interface are connected through an anti-sinking pipeline. The water inlet pipeline is connected to the filtering circulation component. An air-filled tube with an air stone plugged into the bottom end is fixed in the cultivation tank, and the air stone is located at the bottom of the conical bottom shell. The drainage pipe is equipped with a drainage control valve, the water inlet pipe is equipped with a first water inlet control valve, a sterilizing device and a second water inlet control valve, and the seedling emergence pipe is equipped with a seedling emergence control valve.

2. The aquatic seedling cultivation device according to claim 1, characterized in that: The filtration circulation component 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 water 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 water inlet pipe.

3. The aquatic seedling cultivation device according to claim 2, characterized in that: The conical bottom shell of the cultivation tank has a taper of 45°.

4. The aquatic seedling cultivation device according to claim 2, characterized in that: The filter assembly comprises a filter frame and a filter. The filter frame comprises an upper conical cylinder and a lower cylindrical cylinder. The upper conical cylinder is provided with a plurality of spaced filter installation areas, and the filter is fixedly installed at the filter installation area.

5. The aquatic seedling cultivation device according to claim 4, characterized in that: The taper of the upper frustum cylinder of the filter frame is 45°.

6. The aquatic seedling cultivation device according to claim 4, characterized in that: The filter frame is plugged and fixed on the upper inner side of the cultivation tank. A plug-in seat is fixed on the upper inner wall of the cultivation tank. The plug-in seat is provided with an annular plug-in groove, and the bottom of the lower cylindrical body is inserted into the annular plug-in groove.

7. The aquatic seedling cultivation device according to claim 6, characterized in that: A sealing rubber ring is arranged between the annular plug-in groove and the bottom of the lower cylindrical body.

8. The aquatic seedling cultivation device according to claim 6, characterized in that: The bracket seat comprises an inverted conical truncated cone sleeve and a plurality of supporting legs, wherein the plurality of supporting legs are evenly distributed along the circumference of the inverted conical truncated cone sleeve, and the inverted conical truncated cone sleeve is fixed to the supporting legs by welding.

9. The aquatic seedling cultivation device according to claim 1, characterized in that: The filter comprises a shell and filter cotton, and a sealing window is arranged on the shell.

10. A method for cultivating shellfish fry before attachment, characterized in that: Based on the aquatic seed cultivation device according to claim 2, the method comprises the following steps: a. Artificial induction of spawning: placing the parent shellfish with mature gonads into the aquatic seed breeding device for artificial induction of spawning, During the induced labor period, water is added and drained, the drainage control valve, the first water inlet control valve and the second water inlet control valve are opened, and the first filter circulation control valve and the second filter circulation control valve are closed at the same time, and new seawater is continuously added to the aquatic seedling cultivation device, and at the same time, water is continuously drained out from the drainage pipe. When the parent shellfish starts to lay eggs and ejaculate, stop adding water and draining water, and close the drainage control valve, the first water inlet control valve and the second water inlet control valve; After a period of time, the parent shellfish have all completed production, and the parent shellfish release sperm and eggs into the water. The sperm and eggs combine with each other to complete fertilization, and the parent shellfish after spawning are taken out of the aquatic seed cultivation device; b. Washing fertilized eggs: When washing fertilized eggs, water is added and drained. The drainage control valve, the first water inlet control valve and the second water inlet control valve are opened, and the first filter circulation control valve and the second filter circulation control valve are closed at the same time. New seawater is continuously added to the aquatic seedling cultivation device from the bottom water inlet pipe. The new seawater rises and pushes the original seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer. The seawater carries a large amount of excess sperm after fertilization and tissue fluid when fertilized eggs are discharged. After being filtered by the filter assembly, the seawater is continuously discharged from the drainage pipe. At the same time, the eggs are blocked by the filter assembly and flow downward with the water and remain in the aquatic seedling cultivation device. When there is no more foam in the seawater and the seawater is very clear, it means that there are very few sperm in the water. At this time, stop adding water and draining water, and close the drainage control valve, the second water inlet control valve and the first water inlet control valve in sequence to complete the egg washing process; c. Fertilized egg hatching: the first step is to add water, drain water and sterilize at the same time, improve water quality by adding water and changing water, open the drainage control valve, the first water inlet control valve and the second water inlet control valve, and close the first filter circulation control valve and the second filter circulation control valve at the same time, and start the ultraviolet sterilizer, and continuously add new seawater from the bottom water inlet pipe to the aquatic seedling cultivation device. The rising seawater pushes the original seawater in the aquatic seedling cultivation device from the bottom layer to the upper layer, and the seawater mixed with organic particles and metabolic products produced by the death and rupture of eggs is filtered by the filter assembly and continuously discharged from the drainage pipe. This process can be started multiple times according to the changes in water quality; The second step is to perform self-circulation purification, open the first filter circulation control valve, the second filter circulation control valve and the first water inlet control valve, and close the drainage control valve and the second water inlet control valve, start the pipeline pump, and the upper seawater in the aquatic seedling cultivation device enters the filter through the connecting pipeline for filtration, and the filtered seawater enters the ultraviolet sterilizer to kill all pathogens, and finally the filtered and sterilized seawater returns to the aquatic seedling cultivation device. This process can be carried out continuously or intermittently according to the water quality conditions; The third step is to inflate the air pipe with the air stone plugged into the bottom during the water addition and drainage period, the self-circulation purification period and the self-circulation purification interruption period, so that the water in the anti-sinking pipe is always in a flowing circulation state, so that the eggs will not settle at the bottom of the aquatic seedling cultivation device, so as to improve the hatching rate. Continuous aeration also keeps the seawater with sufficient dissolved oxygen content. After a period of incubation, all fertilized eggs hatch and develop into D-shaped larvae, entering the planktonic larvae culture stage; d. Cultivation of planktonic larvae: During the cultivation of planktonic larvae, the aquatic seed cultivation device is subjected to alternating self-circulation purification and water addition and drainage operations, a large amount of feces and other organic debris produced by the larvae are discharged from the cultivation device, pathogens are killed by an ultraviolet disinfector, and air is inflated in the inflation tube connected to the air stone at the bottom, while the larvae are kept in a suspended state, the seawater is kept at a high dissolved oxygen content, a stable and good growth environment is provided for the larvae, thereby improving the larval cultivation density, survival rate and quality. The cultivation time is 6 to 20 days, and the planktonic larvae cultivation density can be controlled at 30 to 40 per milliliter.

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