Apparatus and method for aquaculturing crustacean

Abstract

Provided are an apparatus and a method for aquaculturing a crustacean, which do not require the replacement of individual compartments according to the growth of the crustacean, and can aquaculture a crustacean while preventing cannibalism of the crustacean without performing excessive feeding. A crustacean is aquacultured using an aquaculture apparatus for crustaceans, wherein the aquaculture apparatus has an aquaculture tank 1 in which an air diffusion pipe 2 is installed. The turbidity of water in the aquaculture tank 1 is set to 50 NTU or more by supplying air bubbles of 1-5,000 μm in size into the aquaculture tank 1 through the air diffusion pipe 2 so as to narrow the visual field / visual range of the crustacean, thereby preventing the cannibalism of the crustacean.

Description

Crustacean farming equipment and farming method

[0001] The present invention relates to a crustacean farming apparatus and method, and more particularly to a crustacean farming apparatus and method that are designed to prevent cannibalism of crustaceans during farming.

[0002] Crustaceans such as shrimp grow by repeatedly molting, and cannibalism of the soft bodies immediately after molting is a major cause of the decline in the number of surviving shrimp and survival yield during aquaculture. This tendency is said to be particularly strong in juvenile shrimp during the growth process.

[0003] Patent Document 1 describes a farming device for crustaceans such as shrimp, which has a large number of individual compartments into which individual shrimps can enter, enabling farming without cannibalism.

[0004] However, the aquaculture device of Patent Document 1 requires changing the size of the individual chambers depending on the growth of the crustaceans, and therefore uses multiple types of individual chambers of different sizes, which results in high costs. Furthermore, in the case of whiteleg shrimp and the like, cannibalism is most prevalent among juvenile shrimp that are only a few centimeters long. Individual chambers for such small-sized juvenile shrimp are costly to manufacture and require a lot of maintenance, including cleaning.

[0005] One method of crustacean farming to increase the culture density outside of individual rooms and mitigate cannibalism is to frequently feed large amounts of food, exceeding satiation. However, increasing the frequency of feeding is economically difficult. In addition, applying exceeding satiation to closed land-based aquaria can lead to deterioration of water quality, such as the production of ammonia, nitrite, and nitrate due to decay, resulting in a decrease in survival rate.

[0006] Patent Document 2 describes a method for denitrifying the breeding water of aquatic organisms under aerobic conditions, in which denitrifying bacteria that reduce nitrate nitrogen in the breeding water are immobilized on porous cellulose and an intermittent water discharge section using a siphon is provided.

[0007] However, with this method, the flow rate decreases due to the adhesion of algae, slime, etc. to the inside of the siphon pipe, requiring periodic manual cleaning. Furthermore, if the water flow rate decreases due to the adhesion and accumulation of suspended matter such as algae in the pipe, the siphon mechanism will no longer function, preventing aerobic denitrification and resulting in a deterioration of water quality.

[0008] Patent No. 6887052 Patent No. 6480015

[0009] The present invention aims to provide a crustacean farming device and a crustacean farming method that eliminates the need to change individual chambers as the crustaceans grow, and that allows crustaceans to be farmed without excessive feeding, preventing cannibalism among the crustaceans.

[0010] The gist of the present invention is as follows.

[0011] [1] A crustacean farming device having a farming tank and an air bubble supplying means for supplying air bubbles to the water in the farming tank, wherein the air bubble supplying means is configured to make the turbidity of the water in the farming tank 50 NTU or more.

[0012] [2] The crustacean cultivation device according to [1], wherein the air bubble supply means has an air diffuser pipe and / or a pressurized water supply pipe arranged at the bottom of the cultivation tank.

[0013] [3] The crustacean farming device according to [1] or [2], wherein the air bubble supplying means supplies air bubbles having a particle size of 1 to 5,000 μm.

[0014] [4] The crustacean farming device according to any one of [1] to [3], further comprising a denitrification treatment means for removing water from the farming tank, denitrifying the water, and returning the denitrified water to the farming tank.

[0015] [5] The crustacean farming device according to [4], wherein the denitrification treatment means comprises a denitrification tank that receives the water in the farming tank, and a turntable that is arranged so that a portion of the turntable is immersed in the water in the denitrification tank.

[0016] [6] The crustacean farming device according to [5], wherein the turntable holds a carrier carrying denitrifying bacteria.

[0017] [7] The crustacean farming device according to [6], wherein a cartridge containing the carrier in a water-permeable case is held on the turntable.

[0018] [8] The crustacean farming device according to [4], wherein the denitrification treatment means comprises: a denitrification tank for receiving water in the farming tank; carriers carrying denitrifying bacteria arranged in the denitrification tank; and water supply / drainage switching means for switching between a state in which the carriers in the denitrification tank are submerged and a state in which the carriers are exposed to the atmosphere.

[0019] [9] A method for cultivating crustaceans using the crustacean cultivating device according to any one of [1] to [8].

[0020] As a result of extensive research to solve the above problems, the inventors have discovered that when cultivating crustaceans with cannibalistic habits in aquaculture tanks, the yield can be improved by allowing air bubbles to be present in the water of the tanks.

[0021] That is, the presence of fine bubbles in the water of the aquaculture tank increases the turbidity of the water, which presumably reduces the visibility of the crustaceans and prevents cannibalism, thereby improving the yield of crustacean farming.

[0022] In one aspect of the present invention, a denitrification treatment means is attached to the culture tank to remove nitrogen components such as nitrate and nitrite, thereby enabling a high rearing density and achieving further improvement in yield.

[0023] Fig. 1 is a configuration diagram of a crustacean farming apparatus according to an embodiment. Fig. 2 is a configuration diagram showing one aspect of a denitrification tank. Fig. 3 is a configuration diagram of a crustacean farming apparatus according to another embodiment. Fig. 4 is a configuration diagram showing one aspect of a denitrification tank. Fig. 5 is a configuration diagram of a crustacean farming apparatus according to an embodiment. Fig. 6 is a configuration diagram of a crustacean farming apparatus according to an embodiment.

[0024] Hereinafter, an embodiment will be described with reference to the drawings.

[0025] 1 shows an embodiment of a crustacean farming apparatus. This crustacean farming apparatus includes a farm tank 1, a pipe 4 for supplying water from the farm tank 1 to a relay tank 5, a pipe 7 and a pump 6 for extracting water from the relay tank 5 and supplying it to a denitrification tank 8, an overflow pipe 9 for returning overflow water from the denitrification tank 8 to the relay tank 5, a pipe 13 and a valve 12 for returning denitrification-treated water from the denitrification tank 8 to the relay tank 5, a filtration pH adjustment tank 20 into which water from the relay tank 5 is introduced, a nitrification tank 21 into which water from the filtration pH adjustment tank 20 is introduced, a receiving chamber 24 for receiving the nitrification-treated water from the nitrification tank 21, and a pump 25 and a pipe 26 for returning water from the receiving chamber 24 to the farm tank 1. When the water in the aquaculture tank 1 is supplied to the pipe 4, it is preferable to install an anti-suction net (not shown) at the intake port of the pipe 4 to prevent crustaceans such as shrimp in the aquaculture tank 1 from being sucked into the pipe 4.

[0026] As shown in Figure 2, the denitrification tank 8 is an intermittent water supply system. In this denitrification tank 8, carriers 20 containing denitrifying bacteria are packed on a grating 11. The pump 6 is operated intermittently to supply water from a pipe 7 into the denitrification tank 8, as shown in Figures 2(a) and 2(b). After the carriers 10 are submerged, the water supply is stopped. The valve 12 is constantly open, and the water in the denitrification tank 8 flows into the relay tank 5 through a pipe 13. The carriers 10 are preferably exposed to the atmosphere (air) and submerged several hundred times a day, for example, 300 to 2,000 times a day, and preferably 400 to 1,000 times a day. Repeated submersion and exposure to air of the carriers 10 denitrifies nitrogen components in the water, such as nitrate. The carriers 10 are typically made of porous cellulose supporting denitrifying bacteria. Sludge collected from a wastewater denitrification tank can be used as the denitrifying bacteria.

[0027] According to the denitrification tank 8 of FIG. 2, maintenance such as cleaning the siphon pipe of the water discharge section and replacing the solenoid valve can be simplified.

[0028] The relay tank 5, denitrification tank 8, filtration pH adjustment tank 20, nitrification tank 21, pumps 6 and 25, and pipes 7, 9 and 13 constitute a water purification unit 27.

[0029] An air diffuser 2 is installed at the bottom of the culture tank 1, and is configured so that air supplied from a blower 3 is supplied into the culture tank 1 in the form of fine bubbles.

[0030] In Figure 1, one water purification unit 27 is installed for one aquaculture tank 1, but it is also possible to install multiple aquaculture tanks 1 (for example, 2 to 10 tanks) side by side and provide one water purification unit 27 for each of them.

[0031] The volume of the culture tank 1 is not particularly limited, but if the volume is small, the breeding efficiency will be low, and if the volume is large, the yield will decrease when the water quality deteriorates or when diseases occur. Therefore, it is recommended to set the volume at 0.05 m ３ Above, especially 0.1m ３ Above, especially 0.2m ３ It is preferable that the length is 200 m or more. ３ Below, especially 10m ３ Below, 3m ３ Below, especially 1m ３ It is preferable that the capacity is less than 300 L (900 mm x 600 mm x 600 mm), and specifically, a capacity of about 300 L (900 mm x 600 mm) to 2000 L can be used.

[0032] The shorter the distance between the aeration pipe 2 and the bottom of the culture tank 1, the better.

[0033] The particle size of the bubbles diffused into the water from the air diffuser 2 is preferably 1 μm or more, particularly 50 μm or more, and 5,000 μm or less, particularly 1,000 μm or less. The particle size of the bubbles increases as the water depth in the aquaculture tank 1 decreases, but it is preferable that the particle size be within the above range throughout the entire area from the deepest part to near the water surface.

[0034] A particle size measuring sensor may be installed to measure the particle size of bubbles in the water in the aquaculture tank 1. As such a particle size measuring sensor, various commercially available sensors that utilize laser diffraction / scattering methods or CCD cameras can be used.

[0035] By diffusing air in this manner, it is preferable to set the turbidity of the water in the culture tank 1 to a range of 50 NTU or more, particularly 100 NTU or more, and especially 300 NTU or more, as measured by a turbidity meter specified in JIS K0801.

[0036] The presence of such fine bubbles in the water in the culture tank 1 increases the turbidity of the water, which likely narrows the field of view / visibility of the crustaceans and prevents cannibalism, thereby improving the yield when cultivating crustaceans.

[0037] It is also possible to form a water flow in the aquaculture tank 1 by stirring the water in the aquaculture tank 1, causing the air bubbles to flow and distribute the air bubbles throughout the aquaculture tank 1. It is also possible to form a water flow in the aquaculture tank 1 by regulating the inflow direction of water flowing into the aquaculture tank 1 from the pipe 26, causing the air bubbles to flow and distribute the air bubbles throughout the aquaculture tank 1.

[0038] In this embodiment, the water in the aquaculture tank 1 is introduced into a water purification unit 27 having a denitrification tank 8, where it is denitrified, and then returned to the aquaculture tank 1, thereby maintaining the nitrate nitrogen concentration of the water in the aquaculture tank 1 at a predetermined value or less. It is preferable that the nitrate nitrogen concentration of the water in the aquaculture tank 1 be maintained at 400 mg-N / L or less, and particularly 30 mg-N / L or less.

[0039] In Fig. 1, the denitrification tank 8 is installed in the relay tank 5. However, as shown in Fig. 3, a denitrification tank 28 may be installed in place of the relay tank 5 and the denitrification tank 8, and a contact disk type denitrification tank may be used as shown in Fig. 4. Furthermore, the installation locations (water intake points) of denitrification treatment means such as the denitrification tank 8 and the denitrification tank 28 are not limited to the locations shown in Figs. 1 and 3, and may be anywhere along the circulation path between the aquaculture tank 1 and the water purification unit 27. While Figs. 5 and 6 show an example in which the denitrification tank 8 and the denitrification tank 28 are installed downstream of the nitrification tank 21, providing a denitrification means downstream of the filtration pH tank 20 in this manner prevents residual feed and feces from flowing into the denitrification tank 8 and the denitrification tank 28 because they are removed in the filtration pH adjustment tank 20.

[0040] Furthermore, in the above embodiment, the aeration pipe 2 is used as the bubble supply means, but a pressurized water supply pipe equipped with a jet outlet for jetting pressurized water, in which air is dissolved at a pressure of about 0.4 to 0.5 MPa in the water in the aquaculture tank 1 or in part of the circulating water circulating between the aquaculture tank 1 and the water purification unit 27, into the aquaculture tank 1, can be used instead of or in combination with the aeration pipe 2. The pressurized water may be produced by any method commonly used to produce pressurized water, and for example, a compressor pressurization method or a vortex pump method can be used.

[0041] 3 and 4, the contact disk type denitrification tank 28 is equipped with a waterwheel-shaped rotating disk 30 equipped with paddles 31 and fitted with cartridges 32 filled with carriers containing denitrifying bacteria. The axis 34 of the rotating disk 30 is horizontal and located near the water surface.

[0042] The rotating disk 30 has a hub portion 33 having a shaft 34 and an outer peripheral ring portion 35 connected by spokes 36. A cartridge 32 filled with a carrier is arranged in a space surrounded by the spokes 36, the hub portion 33, and the outer peripheral ring portion 35 so as to be able to be inserted and removed.

[0043] The cartridge 32 filled with the carriers has an isosceles triangular or sector-shaped side view as shown in the figure. The cartridge 32 is a water-permeable case filled with the carriers. The case can be made of a material such as mesh. If the thickness of the cartridge 32 in the direction of the axis 34 is too large, it will come into contact with the shrimp, so it is preferable to determine the thickness in consideration of the depth of the aquarium.

[0044] The carrier containing denitrifying bacteria may be one in which denitrifying bacteria are supported on porous cellulose, etc. Note that if denitrifying bacteria are introduced from outside, reducing organisms that are harmful to the crustaceans being cultured may be introduced into the aquaculture water system. Therefore, it is preferable to intermittently supply water from the circulating aquaculture tank 1 to a carrier that does not support microorganisms, thereby repeatedly immersing the carrier and exposing it to the atmosphere, thereby naturally supporting the denitrifying bacteria.

[0045] As the denitrifying bacteria, sludge collected from a denitrification treatment tank for wastewater can be used.

[0046] In one example of the present invention, the diameter of the turntable 30 is preferably 0.5 to 3 m, for example, about 1 m, and the ratio of the area of ​​the turntable 30 that is submerged in water to the total area of ​​the turntable 30 is preferably 30 to 70%, and particularly preferably about 50%.

[0047] A drive device such as a motor (not shown) rotates the turntable 30 at 15 to 60 revolutions per hour. As the turntable 30 rotates, the cartridge 32 alternately comes into contact with the air (atmospheric air) and the water in the denitrification tank 8, thereby carrying out aerobic denitrification treatment.

[0048] In Figures 3 and 4, the turntable 30 is rotated by a drive unit, but it may also be rotated by pouring water on it like a waterwheel, or by using the flow of water from a water tank.

[0049] When rotating the material using a water flow, the rotation speed can be adjusted using gears and brakes, and the contact time between the gas phase and the water phase can be controlled.

[0050] When the carrier is worn out or when adhesion of algae, slime, etc. is confirmed, the carrier can be easily replaced by replacing the cartridge 32.

[0051] As described above, this crustacean farming device can prevent cannibalism and deterioration of water quality, which hinder improvement in crustacean farming efficiency.

[0052] In the method for cultivating crustaceans of the present invention, aeration may be stopped or reduced during feeding, which makes it easier for the crustaceans to find food and slows the water flow, making it easier for the crustaceans to eat the food.

[0053] The feed can be ordinary dry pellets, moist pellets, sterilized live feed, etc. There is no need to feed more than satiation.

[0054] The crustaceans to be cultured using the crustacean culture device and method of the present invention are not particularly limited and include shrimp, crabs, crayfish, hermit crabs, etc. However, the present invention is particularly suitable for cultivating shrimp, which are prone to cannibalism, particularly juvenile shrimp, but is not limited to juvenile shrimp and can also be applied to the cultivating of shrimp at or above the juvenile stage. Examples of shrimp include vannamei shrimp and black tiger shrimp.

[0055] The density of the crustaceans in the culture tank 1 is preferably changed according to the growth of the shrimp, and for juvenile shrimp (less than 3 cm in length), it is preferably more than 1 fish / L and not more than 100 fish / L, particularly 10 to 100 fish / L, and especially 20 to 60 fish / L, while for shrimp at a growth stage above juvenile shrimp (3 cm or more in length), it is preferably about 0.1 to 1 fish / L, particularly 0.2 to 0.5 fish / L.

[0056] Since the desirable density of crustaceans in the culture tank 1 varies depending on the growth of the shrimp, it is preferable to culture them in separate tanks such as a juvenile shrimp tank, a first intermediate tank, a second intermediate tank, and a shipping tank according to their growth so as to achieve the desirable density.

[0057] The water purification unit 27 having the denitrification tank can be used to treat not only water in shrimp culture tanks (first intermediate tank, second intermediate tank, shipping tank) during the growth period of shrimp or above, or at the time of shipping, but also water in culture tanks for crustaceans other than shrimp at various stages of growth, and various types of wastewater containing nitrate nitrogen other than water in culture tanks for crustaceans (for example, water in culture tanks for fish such as flounder or shellfish such as abalone). The nitrate nitrogen concentration in this nitrogen-containing wastewater is preferably 50 mg-N / L or less, particularly 20 mg-N / L or less, in the case of fish culture water, and 30 mg-N / L or less, particularly 5 mg-N / L or less, in the case of shellfish culture water.

[0058] Example 1 Using the farming apparatus shown in FIG. 1 (without the installation of the denitrification tank 8), baby shrimp and medium-sized shrimp were farmed for three days, and the number of remaining baby shrimp was measured.

[0059] The specifications of the aquaculture equipment are as follows:

[0060] Capacity of aquaculture tank 1: 400 L (water depth 400 mm) Capacity of relay tank 5: 100 L Capacity of filtration pH adjustment tank 20: 150 L Volume of nitrification tank 21: 150 L

[0061] In the filtration pH adjustment tank 20, the pH was adjusted to about 7.4 using coral sand as a filtering material.

[0062] Other operating conditions are as follows:

[0063] <Amount of Circulating Water> The amount of circulating water (flow rate of the pipes 4 and 26) was set to 18.8 L / min.

[0064] <Shrimp> 150 baby shrimp with an average body length of 15 mm and 5 medium-sized shrimp with an average body length of 60 mm were placed in the culture tank 1 .

[0065] <Feeding> Three times a day, 0.5 g of juvenile Tiger Prawn No. 2 manufactured by Hayashikane Sangyo Co., Ltd. was fed as feed to the culture tank 1. In Example 1, the microbubble generator was stopped for 30 minutes after the feed was fed.

[0066] <Air bubbles> Air bubbles with an average particle size of 5 μm were supplied from a microbubble generator to the bottom of the culture tank 1, and the turbidity in the culture tank 1 was set to approximately 170 to 200 NTU. Note that the supply of air bubbles was stopped during feeding. Turbidity was measured using a transmitted light turbidity meter TC-500 manufactured by OPTEX Corporation.

[0067] <Results> The number of baby shrimp in the culture tank 1 was measured, and there were 150 on the second day and 142 on the third day, giving a survival rate of 94.7% over three days.

[0068] Comparative Example 1 A test was carried out under the same conditions as in Example 1, except that microbubbles were not supplied.

[0069] <Results> The number of baby shrimp in the culture tank 1 was measured, and there were 40 on the second day and 26 on the third day, giving a survival rate of 17.3% over three days.

[0070] <Discussion> From these results, it was confirmed that supplying microbubbles into the culture tank 1 prevented (suppressed) cannibalism among shrimp, and significantly increased the survival rate of juvenile shrimp.

[0071] Reference Example 1 (Measurement of change over time in nitrate ion concentration in culture tank 1 (with denitrification tank in operation)) Medium-sized shrimp were cultured using the large culture apparatus shown in FIG. 1, and the change over time in nitrate ion concentration in culture tank 1 was measured.

[0072] The specifications of the aquaculture equipment are as follows:

[0073] Volume of aquaculture tank 1: 2800 L (water depth 400 mm) Volume of relay tank 5: 400 L Volume of denitrification tank 8: 200 L Volume of filtration pH adjustment tank 20: 300 L Volume of nitrification tank 21: 400 L

[0074] The denitrification tank 8 was filled with 10 kg of porous cellulose. Between the relay tank 5 and the denitrification tank 8, the pump 6 was turned on to supply water to the denitrification tank 8 for 1 minute, and then the pump 6 was turned off to stop the supply of water to the denitrification tank 8 for the time t (t = 1, 5, 9 or 14 min) shown in Table 1. The water supply rate when the pump 6 was on was 200 L / min.

[0075] In the filtration pH adjustment tank 20, the pH was adjusted to about 7.4 using coral sand as a filtering material.

[0076] Other operating conditions are as follows:

[0077] <Amount of Circulating Water> The amount of circulating water (flow rate of the pipes 4 and 26) was set to 150 L / min.

[0078] <Shrimp> 1,660 baby shrimp with an average body length of 15 mm were placed in culture tank 1.

[0079] <Feeding> 5 g of Tiger Prawns Sigma P-2 manufactured by Hayashikane Sangyo Co., Ltd. was fed to the culture tank 1 three times a day.

[0080] <Air bubbles> No air bubbles were supplied.

[0081] <Results> Table 1 shows the OFF time t (t = 1, 5, 9, or 14 min) of the water supply pump 6 from the relay tank 5 to the denitrification tank 8 and the change over time in the nitrate ion concentration in the aquaculture tank 1. The nitrate ion concentration was measured using a seraNO3 test (detection limit 10 mg / L) manufactured by Sera Japan Co., Ltd.

[0082] Reference Example 2 (Measurement of Changes in Nitrate Ion Concentration Over Time in Culture Tank 1 (Denitrification Tank Not in Operation)) A test was conducted under the same conditions as in Reference Example 1, except that the denitrification tank 8 was not in operation (water was not supplied to the denitrification tank 8 from the relay tank 5). The results are shown in Table 1.

[0083]

[0084] <Discussion> As shown in Table 1, in Reference Example 1 in which the denitrification tank 8 was operated, it was observed that the nitrate ion concentration in the aquaculture tank 1 was significantly lower. On the other hand, in Reference Example 2 in which the denitrification tank 8 was not operated, it was observed that the nitrate ion concentration in the aquaculture tank 1 was higher, reaching approximately 25 mg / L.

[0085] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible within the scope of the effects of the invention. This application is based on Japanese Patent Application No. 2024-008856 filed on January 24, 2024, the entire contents of which are incorporated by reference.

[0086] REFERENCE SIGNS LIST 1 Aquaculture tank 2 Aeration pipe 3 Blower 4, 7, 9, 13, 26 Piping 6, 25 Pump 8, 28 Denitrification tank 12 Valve 20 Filtration pH adjustment tank 21 Nitrification tank 27 Water purification unit 30 Turntable 31 Paddle 32 Cartridge 33 Hub portion 34 Shaft 35 Outer ring portion 36 Spoke

Claims

1. In a crustacean cultivation apparatus having a cultivation tank and a bubble supply means for supplying bubbles to the water in the cultivation tank, the bubble supply means is characterized in that it makes the turbidity of the water in the cultivation tank 50 NTU or more.

2. The crustacean cultivation apparatus according to claim 1, wherein the bubble supply means has a diffuser pipe and / or a pressurized water supply pipe arranged at the bottom of the cultivation tank.

3. The crustacean cultivation apparatus according to claim 1, wherein the bubble supply means supplies bubbles having a particle size of 1 to 5,000 μm.

4. The crustacean cultivation apparatus according to claim 1, further comprising a denitrification treatment means for taking out the water in the cultivation tank, performing denitrification treatment on the water, and returning the denitrification-treated water to the cultivation tank.

5. The crustacean cultivation apparatus according to claim 4, wherein the denitrification treatment means has a denitrification tank for receiving the water in the cultivation tank and a rotating disk arranged so that a part thereof is immersed in the water in the denitrification tank.

6. The crustacean cultivation apparatus according to claim 5, wherein a carrier carrying aerobic denitrifying bacteria is held on the rotating disk.

7. The crustacean cultivation apparatus according to claim 6, wherein a cartridge housing the carrier in a water-permeable case is held on the rotating disk.

8. The crustacean cultivation apparatus according to claim 4, wherein the denitrification treatment means has a denitrification tank for receiving the water in the cultivation tank, a carrier carrying denitrifying bacteria arranged in the denitrification tank, and a water supply / drainage switching means for switching between a state where the carrier in the denitrification tank is submerged in water and a state where the carrier is exposed to the atmosphere by intermittent water supply and constant drainage.

9. A method for cultivating crustaceans using the crustacean cultivation apparatus according to any one of claims 1 to 8.

Images