Crustacean aquaculture device and crustacean production method

Abstract

Provided is a technology that enables yield to be improved with respect to crustacean inland aquaculture. This crustacean aquaculture device for inland aquaculture is characterized: by comprising a water tank, a plurality of nets that divide the inside of the water tank into a plurality of regions, and a holding part for securing the plurality of nets in a stacked manner; and in that the plurality of regions are configured so that the crustaceans can move back and forth. This crustacean production method for inland aquaculture is characterized by including a step for farming crustaceans using a water tank that is divided into a plurality of regions by a plurality of nets which are disposed in a stacked manner, and that is configured so that the crustaceans can move back and forth in the plurality of regions.

Description

Crustacean farming device and crustacean production method

[0001] The present disclosure relates to a shellfish farming device.

[0002] Conventionally, farming devices for land-based farming of crustaceans such as shrimp and crabs have been proposed. For example, Patent Document 1 discloses a farming device that prevents cannibalism by housing individual shrimp in a number of consecutive compartments.

[0003] Japanese Patent Application Laid-Open No. 2021-112182

[0004] The aquaculture device described in Patent Document 1 has room for improvement in terms of the yield of cultivated crustaceans. Therefore, there has been a demand for technology that can improve the aquaculture yield in land-based crustacean aquaculture.

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, there is provided a crustacean farming device. This crustacean farming device is a crustacean farming device for land-based farming, and is characterized in that it includes an aquarium, a plurality of nets that divide the interior of the aquarium into a plurality of areas, and a holder that stacks and secures the plurality of nets, the plurality of areas being configured to allow the crustaceans to move between. With this form of crustacean farming device, the interior of the aquarium is divided into a plurality of areas by the stacked nets, and the plurality of areas are configured to allow the crustaceans to move between, thereby improving the farming yield in land-based crustacean farming.

[0007] (2) In the Crustacean farming device described in (1) above, the spacing between the stacked nets may be 10 mm or more and 300 mm or less. According to this form of Crustacean farming device, the spacing between the stacked nets is 10 mm or more and 300 mm or less, so that the device can be suitably used for cultivating saltwater-swimming edible shrimp such as whiteleg shrimp.

[0008] (3) In the Crustacean farming apparatus described in (1) or (2) above, the mesh size of the net may be 2 mm or more and 25 mm or less. This type of Crustacean farming apparatus has a mesh size of 2 mm or more and 25 mm or less, making it suitable for use in cultivating saltwater-swimming edible shrimp such as whiteleg shrimp.

[0009] (4) In the Crustacean farming device according to any one of (1) to (3), the plurality of nets and the holding unit may be integrated. In this form of the Crustacean farming device, the plurality of nets and the holding unit are integrated, which makes it easy to install and move the nets, and as a result, the interior of the tank can be easily divided into a plurality of areas.

[0010] (5) In the crustacean farming apparatus according to any one of (1) to (4), the crustaceans may be seawater-swimming edible shrimp. This type of crustacean farming apparatus can improve the yield of seawater-swimming edible shrimp in land-based farming.

[0011] (6) In the Crustacean farming apparatus described in (5) above, the seawater-swimming edible shrimp may be whiteleg shrimp. This type of Crustacean farming apparatus can improve the yield of whiteleg shrimp in land-based farming.

[0012] (7) According to another aspect of the present disclosure, there is provided a method for producing Crustaceans. This method for producing Crustaceans in land-based aquaculture is characterized in that it includes a step of cultivating the Crustaceans in an aquarium divided into multiple areas by a plurality of stacked nets, the multiple areas being configured to allow the Crustaceans to move between. According to this aspect of the method for producing Crustaceans, the Crustaceans are cultivated in an aquarium divided into multiple areas by a plurality of stacked nets, the multiple areas being configured to allow the Crustaceans to move between, and therefore the cultivation yield can be improved in land-based Crustacean aquaculture.

[0013] The present disclosure can be realized in various forms, for example, a crustacean farming system, a method for manufacturing a crustacean farming device, a crustacean farming method, etc.

[0014] A top view schematically showing the overall configuration of the aquaculture device. A perspective view schematically showing the overall configuration of the aquaculture rack. A perspective view schematically showing the overall configuration of the aquaculture device according to a modified example. A top view schematically showing the overall configuration of the aquaculture device according to a modified example. A top view schematically showing the overall configuration of the aquaculture device according to a modified example. A perspective view schematically showing the overall configuration of the aquaculture rack according to a modified example. A perspective view schematically showing the overall configuration of the aquaculture rack according to a modified example. An explanatory diagram showing an overview of the device used in the experiment.

[0015] A. Embodiment: FIG. 1 is a top view schematically illustrating the overall configuration of an aquaculture device 100 according to one embodiment of the present disclosure. The aquaculture device 100 is used for cultivating crustaceans in land-based aquaculture. Crustaceans to be cultivated include, but are not limited to, shrimp, crabs, and the like, and may be either freshwater or saltwater crustaceans. The crustaceans to be cultivated are preferably pelagic shrimp, more preferably pelagic shrimp, and even more preferably saltwater-swimming edible shrimp. Saltwater-swimming edible shrimp include, but are not limited to, whiteleg shrimp (Litopenaeus vannamei), Korean shrimp (Penaeus chinesis), blue shrimp (Penaeus stylirostris), banana shrimp (Penaeus merguiensis), and Indian shrimp (Penaeus indicus). As the saltwater-swimming edible shrimp, vannamei shrimp is particularly preferred. The crustaceans to be cultured may be immature individuals such as juvenile shrimp or juvenile crab, or may be mature individuals.

[0016] The aquaculture device 100 includes an aquarium 10, a net 20, and a holder 30. In this embodiment, the aquarium 10 has a generally rectangular shape with rounded corners when viewed from above. The aquarium 10 is configured to store rearing water therein, and crustaceans are reared therein. The rearing water is not particularly limited and is selected depending on the crustaceans to be reared. If the crustaceans to be reared are freshwater crustaceans, for example, fresh water or well water may be used. If the crustaceans to be reared are marine crustaceans, for example, salty water such as seawater, artificial seawater, or brackish water may be used. The depth of the aquarium 10 is not particularly limited and may be, for example, 300 mm to 1500 mm, or 500 mm to 1000 mm. In addition, the aquaculture device 100 may be a closed circulation type land-based aquaculture device that circulates all or almost all of the breeding water discharged from the aquarium 10 and returns it to the aquarium 10, or it may be a semi-closed circulation type land-based aquaculture device that circulates a portion of the breeding water discharged from the aquarium 10 and returns it to the aquarium 10.

[0017] The aquaculture device 100 of this embodiment has a configuration in which a plurality of aquaculture racks 40, each of which integrates a net 20 and a holder 30, are arranged inside the aquarium 10. In the example shown in Fig. 1, four aquaculture racks 40 having a generally rectangular external shape when viewed from above and two aquaculture racks 40 having a generally trapezoidal external shape when viewed from above are combined and installed to fit the shape of the aquarium 10. In addition to the aquaculture racks 40, a circulation pump, a microbial purification device, a wave-making device, artificial seaweed, etc., which are not shown, may also be provided inside the aquarium 10.

[0018] Fig. 2 is a perspective view showing a schematic configuration of the aquaculture rack 40. In the example shown in Fig. 2, the aquaculture rack 40 has a generally rectangular external shape when viewed from above. In the example shown in Fig. 2, the aquaculture rack 40 has five nets 20 stacked vertically and a holder 30. All of the multiple nets 20 are formed to be approximately the same size and shape, and are stacked so as to be approximately parallel to the bottom surface of the aquarium 10.

[0019] The net 20 divides the interior of the aquarium 10 into multiple regions. The net 20 has multiple pores formed throughout its entirety, each large enough to allow the aquaculture water to pass through. The specific configuration of the net 20 is not particularly limited, but may be, for example, a net made of woven mesh fibers made of resin such as polyethylene or nylon, or a punched board made of resin such as polyvinyl chloride, with multiple pores punched into it. The shape of the pores is not particularly limited, and may be any shape, such as a square, circle, or polygon. The mesh size of the net 20, i.e., the size of the pores formed in the net 20, is not particularly limited, but is preferably large enough to prevent the crustaceans from passing through, allowing the crustaceans to land and rest stably. Furthermore, the mesh size is preferably large enough to prevent clogging due to dirt in the aquarium 10. The mesh size of the net 20 is preferably 1 mm to 50 mm, more preferably 2 mm to 25 mm, and even more preferably 3 mm to 10 mm. In the present disclosure, the "mesh size of the net 20" refers to the size of the pores formed in the net 20. For example, if the pores formed in the net 20 are rectangular, the mesh size of the net 20 corresponds to the dimension of the long side of the pores, and if the pores formed in the net 20 are circular, the mesh size of the net 20 corresponds to the diameter of the pores. Note that the mesh sizes of the nets 20 may all be the same in a single net 20, or may be partially or entirely different. Furthermore, the mesh sizes of the nets 20 may all be the same in multiple nets 20, or may be partially or entirely different.

[0020] The holding unit 30 secures multiple nets 20 in a stacked manner. In this embodiment, the holding unit 30 is formed by combining multiple thin tubes vertically and horizontally. In this embodiment, the holding unit 30 is formed from a hard polyvinyl chloride tube, but it may be formed from any material, such as other resin tubes made from polyethylene, polypropylene, etc. Furthermore, in this embodiment, the holding unit 30 is formed so that its upper portion is located above the water surface of the aquarium 10. Therefore, a user of the aquaculture device 100 can easily install or move the aquaculture rack 40 by grasping the upper portion of the holding unit 30.

[0021] The method for integrating the mesh 20 and the holding portion 30 is not particularly limited, but for example, they may be fixed to each other with a cable tie or string, or they may be integrated by fitting or welding, etc.

[0022] The spacing between the stacked nets 20 is not particularly limited as long as it allows the crustaceans to enter. The spacing between the stacked nets 20 is preferably large enough not to hinder the movement of the crustaceans, and is also preferably large enough to increase the landing area and prevent overcrowding inside the aquarium 10. The spacing between the stacked nets 20 is preferably 10 mm to 300 mm, more preferably 20 mm to 150 mm, even more preferably 30 mm to 100 mm, and even more preferably 50 mm to 80 mm. The spacing between the nets 20 may be equal, or some or all of the spacing may be different.

[0023] The number of stacked nets 20 is not particularly limited and may be set appropriately depending on the culture conditions such as the depth of the aquarium 10. From the viewpoint of increasing the landing area of ​​the crustaceans, the number of stacked nets 20 is preferably 3 or more, and more preferably 5 or more. From the viewpoint of ensuring that even the topmost net 20 has a water depth sufficient to prevent crustaceans from jumping out of the water surface of the aquarium 10, the number of stacked nets 20 is preferably 15 or less, and more preferably 10 or less.

[0024] By stacking and fixing multiple nets 20, the interior of the aquarium 10 is divided into multiple regions. The multiple regions are configured to allow the crustaceans to move between them. For example, in the example shown in FIG. 1 , the presence of at least one of gaps between the multiple culture racks 40 and gaps between the culture racks 40 and the inner wall of the aquarium 10 allows the crustaceans to move between the multiple regions. The gaps between the culture racks 40 and between the culture racks 40 and the inner wall of the aquarium 10 are preferably 10 mm to 300 mm, more preferably 20 mm to 150 mm, even more preferably 30 mm to 100 mm, and even more preferably 50 mm to 80 mm. The stacked nets 20 may be formed with different sizes and shapes to ensure space for the crustaceans to move between the multiple regions. The multiple regions can also be referred to as "tiers."

[0025] According to the aquaculture device 100 of this embodiment, the crustaceans to be cultured can be dispersed among the various areas (layers), preventing overcrowding within the aquarium 10. As a result, cannibalism among the crustaceans can be suppressed, improving the culture yield. In this specification, "culture yield" refers to the ratio of the number of shippable individuals obtained to the number of individuals introduced.

[0026] The inventors of the present application also discovered that even pelagic shrimp, such as whiteleg shrimp, which swim three-dimensionally in the water, require a certain landing area for resting. According to the aquaculture device 100 of this embodiment, the interior of the aquarium 10 is divided into multiple levels by the vertically stacked nets 20, so that the landing area within the aquarium 10 can be increased and crowding within the aquarium 10 can be prevented. As a result, cannibalism among crustaceans can be further suppressed, thereby further improving the aquaculture yield.

[0027] Furthermore, according to the aquaculture device 100 of this embodiment, since the plurality of nets 20 and the holding unit 30 are integrated, multiple floors can be easily formed within the aquarium 10. Furthermore, by using a unit-shaped aquaculture rack 40 in which the plurality of nets 20 and the holding unit 30 are integrated, the nets 20 can be easily installed and moved within the aquarium 10, making it possible to easily divide the interior of the aquarium 10 into multiple areas. Furthermore, by using a unit-shaped aquaculture rack 40, the nets 20 can be easily moved and removed within the aquarium 10, thereby preventing a decrease in convenience. In the aquaculture device 100 of this embodiment, multiple aquaculture racks 40 are combined and installed to match the shape of the aquarium 10. As a result, a tiered structure of the nets 20 can be formed over a wide area within the aquarium 10, thereby further increasing the landing area.

[0028] According to another aspect of the present disclosure, there is provided a method for producing crustaceans in land-based aquaculture. This production method includes a process of cultivating crustaceans using an aquarium divided into multiple areas by multiple nets arranged in layers, with the aquarium configured to allow crustaceans to move between the multiple areas. This process may be a process of raising crustaceans using the aquaculture device 100 described above. According to this production method, the crustaceans to be cultivated can be dispersed among the various areas, thereby preventing overcrowding within the aquarium 10. As a result, cannibalism among the crustaceans can be suppressed, thereby improving the aquaculture yield.

[0029] B. Modification: Fig. 3 is a perspective view showing a schematic configuration of the aquaculture device 100a in a modification. The aquaculture device 100 in the above embodiment has a configuration in which a plurality of unit-shaped aquaculture racks 40, each of which integrates the net 20 and the holder 30, are arranged inside the aquarium 10, but the present disclosure is not limited to this.

[0030] In the aquaculture device 100a shown in Figure 3, pillars located inside the aquarium 10a function as holders 30a, and nets 20a are stacked and fixed to the holders 30a. The holders are not limited to pillars, and may be formed by any other member located inside the aquarium. For example, a pump or purifier installed inside the aquarium 10a may function as the holder, or hooks or protrusions provided inside the aquarium 10a may function as the holder. With this configuration, the interior of the aquarium 10a can be divided into multiple regions by stacking multiple nets 20a.

[0031] FIG. 4 is a top view schematically illustrating the general configuration of an aquaculture device 100b according to a modified example. FIG. 5 is a top view schematically illustrating the general configuration of an aquaculture device 100c according to a modified example. The configuration of the aquaculture device 100 according to the above embodiment is merely an example and can be modified in various ways. For example, as shown in FIG. 4, the aquaculture tank 10b may have any shape, such as a generally circular shape when viewed from above. The aquaculture rack 40 may be formed in any shape to match the size and shape of the aquaculture tank 10b. For example, as shown in FIG. 5, the number of aquaculture racks 40 installed per aquaculture tank 10c may be one, not multiple. Note that the configurations shown in FIGS. 4 and 5 are not limited to the configuration in which the aquaculture racks 40 are installed, but are also applicable to a configuration in which any component located inside the aquaculture tank 10a functions as the holder 30a.

[0032] FIG. 6 is a perspective view schematically illustrating the configuration of a culture rack 40a according to a modified example. FIG. 7 is a perspective view schematically illustrating the configuration of a culture rack 40b according to a modified example. The configuration of the culture rack 40 in the above embodiment is merely an example and can be modified in various ways. For example, as shown in FIG. 6 , the multiple nets 20 do not necessarily have to be substantially parallel to the bottom of the aquarium 10, but may be stacked at an angle to the bottom of the aquarium 10. This configuration allows hovering crustaceans to easily enter the gaps between the nets 20. Furthermore, as shown in FIG. 7 , the multiple nets 20 may be stacked substantially perpendicular to the bottom of the aquarium 10. This configuration increases the landing area for crustaceans that rest on the nets 20. Note that while FIGS. 6 and 7 show the configuration of the culture racks 40a and 40b, the same applies not only to the configuration in which the culture racks 40a and 40b are installed, but also to a configuration in which any component located inside the aquarium 10a functions as the holding unit 30a. That is, the plurality of nets 20 are not limited to being stacked substantially parallel to the bottom surface of the aquarium 10, 10a, but may be stacked diagonally or substantially perpendicularly.

[0033] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0034] 1. Experimental Materials and Methods Aquaculture experiments were conducted under the following conditions.

[0035] FIG. 8 is an explanatory diagram showing an overview of the equipment used in the aquaculture experiment. In the example, four large-sized aquaculture racks, each consisting of five rectangular nets with a long side of 700 mm and a short side of 600 mm stacked at 80 mm intervals, and two small-sized aquaculture racks, each consisting of five square nets with a side of 500 mm stacked at 80 mm intervals, were installed in an aquarium for aquaculture. In the comparative example, no aquaculture racks or nets were installed. Other conditions, such as equipment and number of rearing days, were the same between the example and comparative example. More specifically, an equipment including a rearing aquarium, a biological filtration tank, and two physical filtration tanks was used. The rearing aquarium was equipped with one water flow pump, two circulation pumps, and one protein skimmer, and was sterilized with an ultraviolet germicidal lamp. The biological filtration tank contained 120 L of filter media, 7.5 kg of coral, one water flow pump, and one boot filter. The physical filtration tank contained one protein skimmer and two boot filters. The crustaceans used for cultivation were whiteleg shrimp. A 2.8 ton tank was used. The water temperature was 28°C. The salinity of the water was 1%. The feeding frequency was 8 times a day, every 3 hours. The rearing period was 21 days. The population density of the introduced fish was 1000 fish / t.

[0036] As a result of the aquaculture experiment, the final overpopulation in the comparative example was 3 kg / t, and the survival rate in the comparative example was 70.6%. In contrast, the final overpopulation in the example was 10 kg / t, and the survival rate in the example was 97.8%. Generally, the higher the overpopulation, the lower the survival rate tends to be due to cannibalism, but in this experiment, the survival rate was high despite the high overpopulation. From the above results, it was found that the cultivation yield of crustaceans can be improved by installing multiple stacked nets inside the aquarium.

[0037] The present invention is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and examples corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0038] 10, 10a, 10b, 10c...Aquarium, 20, 20a...Net, 30, 30a...Holding section, 40, 40a, 40b...Aquaculture shelf, 100, 100a, 100b, 100c...Aquaculture device

Claims

1. A crustacean farming device for land-based aquaculture, comprising: an aquarium; a plurality of nets that divide the inside of the aquarium into a plurality of areas; and a holding section that stacks and fixes the plurality of nets, wherein the plurality of areas are configured to allow the crustaceans to move between them.

2. A crustacean farming device as described in claim 1, characterized in that the distance between the stacked nets is between 10 mm and 300 mm.

3. A crustacean farming device as claimed in claim 1, characterized in that the mesh size of the mesh is between 2 mm and 25 mm.

4. A crustacean farming device as claimed in claim 1, characterized in that the plurality of nets and the holding section are integrated together.

5. The crustacean farming apparatus according to claim 1, characterized in that the crustaceans are seawater-swimming edible shrimp.

6. The crustacean farming apparatus according to claim 5, characterized in that the seawater swimming edible shrimp is a whitenamei shrimp.

7. A method for producing Crustaceans in land-based aquaculture, comprising the step of cultivating the Crustaceans in an aquarium divided into a plurality of areas by a plurality of stacked nets, the aquarium being configured to allow the Crustaceans to move between the plurality of areas.

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