Method for producing sea urchin, feed for sea urchin, method for producing feed, and method for raising, cultivating, storing or transporting sea urchin

Abstract

To provide a method for producing sea urchins, feed to be given to the sea urchins, method for producing the feed and method for rearing, culturing, storing or transporting the sea urchins, which can improve the commercial value or production efficiency of sea urchins.SOLUTION: A method for producing sea urchins U includes releasing sea urchins U with underdeveloped gonads into rearing cages 102 installed in a rearing tank 101, and then feed F is fed. The feed F is primarily composed of sake lees from shochu made from barley as the main ingredient, along with agar as a coagulant. In this case, the inventor confirmed that when the feed F containing sake lees is fed to the sea urchins U with undeveloped gonads, the color of the gonads of the sea urchins U is whitened. Based on this, producers can produce the sea urchins U whose gonads are whitened by feeding the feed F to the sea urchins U with underdeveloped gonads.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing sea urchins, feed to be given to sea urchins, a method for producing the feed, and a method for raising, cultivating, storing or transporting sea urchins. [Background technology]

[0002] Conventionally, sea urchins have been reared or cultivated by artificially hatching or by capturing them from natural marine areas. For example, Patent Document 1 below discloses a marine invertebrate feed that improves the survival rate of sea urchins, promotes the growth of shell length, and increases individual body weight by feeding sea urchins a feed containing seaweed powder and food processing residues such as sake lees, and a method for producing the feed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-91558

[0004] However, even if the marine invertebrate feed and the method for producing the feed described in Patent Document 1 are used, there is a constant demand for improving the commercial value of sea urchins at sea urchin production sites.

[0005] The present invention has been made to address the above-mentioned problems, and its object is to provide a method for producing sea urchins, feed to be given to sea urchins, a method for producing feed, and methods for raising, cultivating, storing, or transporting sea urchins, which can improve the commercial value of sea urchins. Summary of the Invention

[0006] To achieve the above object, the present invention is characterized by a method for producing sea urchins, in which sea urchins with underdeveloped gonads are fed a feed containing sake lees.

[0007] According to the features of the present invention configured as described above, the sea urchin production method involves feeding sea urchins with underdeveloped gonads with a feed containing sake lees, so that sake lees can be used as a feed instead of the algae that sea urchins with underdeveloped gonads (hereinafter also referred to as "juvenile sea urchins") normally eat. Here, "underdeveloped gonads" refers to the state in which the gonads have not yet developed until about one year after sea urchin larvae hatch from fertilized eggs.

[0008] It is known that sea urchins typically feed on different diets during their development. Specifically, during the planktonic larval stage, when they live floating in the water, they primarily feed on phytoplankton. However, after metamorphosis into juvenile sea urchins, they primarily feed on algae such as kelp (a type of green alga) or epiphytic diatoms (diatoms that grow attached to an underwater substrate). As they grow, they begin to feed on kelp or wakame seaweed. For this reason, in conventional sea urchin production, algae for juvenile sea urchins must be artificially produced or harvested from the wild, resulting in an environmental burden for the juvenile sea urchins. However, in the sea urchin production method of the present invention, a feed containing sake lees can be used as an alternative to conventional juvenile sea urchin feed. This is based on the inventor's confirmation that the sake lees-containing feed of the present invention is equivalent to conventional juvenile sea urchin feed in terms of sea urchin growth rate and is effective as a sea urchin feed. Therefore, the sea urchin production method enables the production of sea urchins using feed with reduced environmental impact.

[0009] The sake lees contained in the feed for the young sea urchins are either the lees generated when the mash is squeezed during the brewing process or the residue remaining after the mash is distilled during the distilling process. They are a slurry-like fluid containing solids such as the main ingredients of distilled alcohol (for example, rice, barley, corn, buckwheat, brown sugar, or potato) or koji. Currently, most of this sake lees have little potential for reuse and are mainly disposed of as waste. However, in the sea urchin production method of the present invention, sea urchins can be produced using this sake lees.

[0010] For these reasons, the sea urchin production method uses feed that reduces the environmental impact of the young sea urchins and contains sake lees that would otherwise be disposed of. This means that sea urchins can be produced using environmentally friendly feed, and the commercial value of sea urchins can be improved as they are highly sustainable.

[0011] Here, sea urchins to which the present invention can be applied include purple sea urchin, northern purple sea urchin, sea urchin, sea urchin, and red sea urchin.

[0012] Another feature of the present invention is that in the method for producing sea urchins, the gonads are whitened by feeding the sea urchins with a feed.

[0013] According to another feature of the present invention configured as described above, the sea urchin production method whitens the gonads by feeding the sea urchins with a feed, thereby producing extremely unique sea urchins with white gonads. Here, the gonads of sea urchins are composed of the ovaries or testes and are the edible part of the sea urchin. These gonads, whether farmed or wild, usually have a yellowish color, such as reddish yellow (orange), yellow, or pale yellow. However, the sea urchins produced by the production method of the present invention have value as a new food ingredient because of their white gonads. They can also be used as samples to clarify the mechanism of sea urchin gonad color development or the relationship between gonad color change and the feed fed to the sea urchins, thereby improving the commercial value or utility value of sea urchins.

[0014] Furthermore, the white color in the context of whitening according to the present invention refers to a color that exhibits a chromaticity in the range of an L* (brightness) value of 65 or more in the L*a*b* color space, an a* (redness) value of 5 or less, and a b* (yellowness) value of 10 or less.

[0015] In addition, the sake lees contained in the sea urchin feed are easy to obtain and require little economic burden, allowing for efficient production of sea urchins.

[0016] To achieve the above objective, the present invention is characterized by a method for producing sea urchins, in which the proportion of gonad weight to the total weight of an individual sea urchin is increased to 8% or more by feeding sea urchins in which the proportion of gonad weight to the total weight of an individual is less than 8% with feed containing sake lees.

[0017] According to the features of the present invention configured as described above, the sea urchin production method can produce sea urchins with a gonad somatic index (GSI), i.e., the ratio of gonad weight to the total weight of a single sea urchin, of less than 8% by feeding them a feed containing sake lees. This is based on the inventor's discovery that feeding sea urchins with a GSI of less than 8% with a feed containing sake lees can increase the GSI of sea urchins to 8% or more. Normally, sea urchins with a GSI of less than 8% do not meet shipping standards and have no commercial value. However, according to the production method of the present invention, the GSI of sea urchins can be increased to 8% or more, thereby making sea urchins with no commercial value commercially valuable. In this case, the GSI ratio should be 8% or more, preferably 10% or more, and more preferably 15% or more.

[0018] Furthermore, according to the production method of the present invention, the feed given to sea urchins contains sake lees, which would otherwise be disposed of as waste, and therefore sea urchins can be produced using environmentally friendly feed, thereby improving the commercial value of sea urchins as highly sustainable sea urchins.

[0019] In order to achieve the above object, the present invention is characterized in that it is a feed to be given to sea urchins with underdeveloped gonads, which contains sake lees.

[0020] According to the features of the present invention configured as described above, the feed given to sea urchins with underdeveloped gonads contains sake lees, which reduces the environmental impact compared to conventional feed for juvenile sea urchins and makes effective use of sake lees that would otherwise be disposed of. Therefore, by feeding this feed to juvenile sea urchins, the feed according to the present invention can add value to the sea urchins as highly sustainable sea urchins raised on an environmentally friendly feed, thereby improving the commercial value of the sea urchins.

[0021] Another feature of the present invention is that the amount of sake lees in the feed is an amount that can whiten the gonads.

[0022] According to another feature of the present invention configured in this manner, the amount of sake lees in the feed given to sea urchins with underdeveloped gonads is sufficient to whiten the gonads, and therefore the gonads of sea urchins fed this feed can be whitened. This is based on the inventor's discovery that feeding sea urchins with underdeveloped gonads with feed containing sake lees can whiten the gonads of the sea urchins. In this case, the amount of sake lees sufficient to whiten the gonads can be determined experimentally in advance.

[0023] In order to achieve the above object, the present invention is characterized in that it is a feed given to sea urchins, which contains distiller's lees produced in the process of producing distilled liquor and agar that solidifies the distiller's lees.

[0024] According to the features of the present invention configured as described above, the feed provided to sea urchins contains distiller's lees produced during the distiller's liquor production process and agar for coagulating the distiller's lees. This eliminates the need to dissolve the agar in water during the feed production process, thereby improving feed production efficiency and reducing environmental impact. This is based on the fact that distiller's lees (i.e., the residue remaining after distilling unrefined sake during the distiller's liquor production process) have a moisture content of approximately 90% or more. Because distiller's lees contain a high moisture content, the agar can be dissolved by mixing it into the distiller's lees, eliminating the need to dissolve the agar in water, which is typically required when agar is used as a coagulant. Therefore, by feeding sea urchins with the feed of the present invention, added value can be added as highly sustainable sea urchins raised on environmentally friendly feed, thereby improving the commercial value of the sea urchins.

[0025] Another feature of the present invention is that the feed is composed only of distiller's lees and agar.

[0026] According to another feature of the present invention, the feed is composed only of distiller's lees and agar, which reduces the cost of raw materials and allows for inexpensive production. In particular, the sake lees contained in the feed are subject to disposal and are easily and inexpensively available, which reduces the cost of raw materials for the feed.

[0027] Another feature of the present invention is that the surface of the feed is whitish in color.

[0028] According to another feature of the present invention configured in this manner, the surface of the feed is whitish, making it easy to distinguish the feed from sea urchins, which are black, green, or reddish-brown, by their colors. In other words, according to the present invention, it is easier to grasp at a glance the number and position of sea urchins, whether or not the sea urchins are consuming feed, and the amount of feed consumed by the sea urchins, compared to when the feed is a color other than whitish. This is particularly effective for juvenile sea urchins, which are smaller in size and therefore more difficult to distinguish from feed than fully grown sea urchins. The feed may have a whitish interior in addition to its surface.

[0029] Here, the term "white" refers to pure white, the brightest grays, the most saturated colors among the hues of chromatic colors (i.e., pure colors) to which white is added, or the lightest, pale colors among the colors to which gray is added (i.e., intermediate colors) to which pure colors are added.

[0030] In order to achieve the above object, the present invention is characterized in that it is a feed given to sea urchins, which contains sake lees in an amount that whitens the sea urchin feces, and has a surface that is a color other than white.

[0031] According to the features of the present invention configured in this manner, the feed contains sake lees in an amount sufficient to whiten the feces of sea urchins, thereby whitening the feces of sea urchins fed this feed. This is based on the inventor's observation of whitish feces of sea urchins raised on the feed of the present invention. Therefore, since the surface of the feed is composed of a color other than whitish, the whitened sea urchin feces and the feed can be easily distinguished by their colors. In other words, according to the present invention, it is easier to determine at a glance whether the sea urchin has ingested the feed and the amount of food intake by the sea urchin, compared to when the feed is whitish in color. Note that the feed may have a color other than whitish inside as well as on the surface.

[0032] Another feature of the present invention is that the feed is formed into a sheet or plate shape.

[0033] According to another feature of the present invention configured in this way, since the feed is formed in a sheet or plate shape, multiple sea urchins can attach to one sheet of feed, providing an opportunity for many sea urchins to eat at the same time, increasing the opportunities for each individual to eat and reducing the amount of food left over.Furthermore, feed formed in a flat shape is easy for sea urchins crawling in the breeding tank to eat, and its shape makes it easy for breeders to monitor the sea urchins.

[0034] Furthermore, by forming the feed into a sheet or plate shape, it can be torn into pieces of an appropriate size by hand, making it easier to feed. In this case, the feed can be torn into pieces of a size that corresponds to the shape of the area where the sea urchins are fed or the size of the sea urchins, and the feed can be provided in a size that is easy to feed or easy for the sea urchins to eat, even in a small breeding tank.

[0035] Furthermore, by forming the feed into a sheet that is at least flexible, the shape of the feed can be deformed to fit the shape of the area where the feed is fed, making it easy to feed even in small breeding tanks and preventing the sea urchins' range of movement within the breeding tank from becoming narrower.

[0036] Furthermore, by forming the feed into a plate-like shape that does not have the flexibility of a rigid body, it can be placed upright or suspended in the rearing tank, and by having sea urchins attach to both sides of the plate-shaped feed, more sea urchins can be given the opportunity to eat at the same time.

[0037] Another feature of the present invention is that the feed is configured to be flexible and pliable.

[0038] According to another feature of the present invention, the feed is flexible and bendable, so that the sea urchins can be easily removed from the tank by pulling up the feed with the sea urchins attached from the tank without directly touching them. Here, "flexible" refers to a softness that is not so stiff that the feed cannot maintain its horizontal or upright positions.

[0039] Another feature of the present invention is that the feed has a surface area of ​​20 cm 2 It is more than that.

[0040] According to another aspect of the invention, the feed is made up of a material having a surface area of ​​20 cm 2 For the above reasons, by having multiple sea urchins attach to one feed, it is possible to increase the opportunity for each sea urchin to feed, and since the sea urchins can be positioned without being in close contact with each other, it is possible to prevent them from injuring or cannibalizing each other. This is based on the fact that the present inventor confirmed that sea urchins start feeding on feed when their shell diameter reaches about 2 cm.

[0041] Another feature of the present invention is that the feed is formed into a block shape.

[0042] According to another feature of the present invention configured in this manner, since the feed is formed in a block shape, multiple sea urchins can simultaneously attach to each side of the block-shaped feed, increasing the opportunity for each individual to eat. In addition, by attaching to different sides, the sea urchins can position themselves without being in close contact with each other, thereby preventing them from injuring or cannibalizing each other.

[0043] Another feature of the present invention is that the feed has a surface area of ​​20 cm 2 It is more than that.

[0044] According to another aspect of the invention, the feed is made up of a material having a surface area of ​​20 cm 2 For the above reasons, by having multiple sea urchins attach to one feed, it is possible to increase the opportunity for each sea urchin to feed, and since the sea urchins can be positioned without being in close contact with each other, it is possible to prevent them from injuring or cannibalizing each other. This is based on the fact that the present inventor confirmed that sea urchins start feeding on feed when their shell diameter reaches about 2 cm.

[0045] Furthermore, the present invention can be implemented not only as an invention of a feed, but also as an invention of a method for raising, cultivating, storing or transporting sea urchins.

[0046] Specifically, it is preferable that any one of the above feeds is fed to sea urchins for rearing, cultivating, storing, or transporting. In the case of an invention of a method for rearing, cultivating, storing, or transporting sea urchins, the same effects as those of the invention of the feed can be expected.

[0047] In order to achieve the above-mentioned object, the present invention is characterized in that it is a method for producing feed to be given to sea urchins, which includes a sake lees mixture production process in which a coagulant is added to sake lees heated to about 80°C or higher to produce a sake lees mixture, and a solidification process in which the sake lees mixture is solidified.

[0048] According to the features of the present invention configured as described above, the feed production method involves adding and dissolving a coagulant directly to sake lees heated to approximately 80°C or higher, thereby eliminating the need for water or seawater to dissolve the coagulant and allowing feed to be produced without diluting the sake lees concentration. In other words, according to the present invention, it is possible to produce feed with a higher concentration of sake lees than feed produced using water or seawater, and thus produce feed with high nutritional value per unit intake of sea urchins. In this case, the heating temperature of the sake lees should be approximately 80°C or higher, preferably 90°C or higher, and more preferably 100°C or higher (above the boiling point).

[0049] Another feature of the present invention is that the method for producing the feed further comprises a color adjustment step of adjusting the color of the sake lees mixture to a color other than white.

[0050] According to another feature of the present invention configured as described above, the method for producing a feed includes a color adjustment step of adjusting the sake lees mixture to a color other than white, so that the sake lees mixture can be adjusted to a color that is easily distinguishable from the whitened sea urchin feces. In other words, according to the present invention, a feed that is easily distinguishable from sea urchin feces can be produced, and therefore it is possible to produce a feed that makes it easy to determine at a glance whether or not the sea urchins have ingested the feed and the amount of food intake by the sea urchins.

[0051] In the method for producing the feed, the color adjustment step may include adjusting the color of the sake lees mixture to a color other than whitish by freezing the sake lees mixture.

[0052] According to this, in the feed production method, the color adjustment step involves freezing the sake lees mixture to adjust the color of the sake lees mixture to a color other than whitish, so the color of the sake lees mixture can be easily adjusted to a color other than whitish. This is based on the inventor's discovery that freezing the sake lees mixture can change the color of the sake lees mixture to a brownish color. In this case, the longer the freezing time of the sake lees mixture, the more the sake lees mixture can be changed to a brownish color.

[0053] The method for producing the feed may further include a thawing step of thawing the frozen sake lees mixture.

[0054] According to this, since the method for producing feed includes a thawing process, it is possible to produce feed that prevents the water temperature of the breeding water from dropping during feeding, compared to when the sake lees mixture is fed to sea urchins while still frozen. [Brief explanation of the drawings]

[0055] [Figure 1] 1 is a longitudinal cross-sectional view schematically illustrating the outline of the configuration of a sea urchin rearing system used in a sea urchin production method according to the present invention. [Figure 2] FIG. 1 is a plan view showing the state inside the breeding tank when the feed according to the present invention is fed to sea urchins. [Figure 3]FIG. 3 is a perspective view showing the outline of the external configuration of the mold for forming the feed shown in FIG. 2. [Figure 4] FIG. 4 is a perspective view showing the outline of the external configuration of the feed molded using the mold shown in FIG. 3. [Figure 5] 5 is a line graph showing the relationship between the shell diameter and the feeding period for sea urchins fed with the feed shown in FIG. 4 and sea urchins fed with Akamoku. [Figure 6] The average values ​​for shell diameter, weight, gonad weight, and gonad weight index (GSI) are shown for sea urchins fed the diet shown in Figure 4 and sea urchins fed salted wakame seaweed after 20 months of rearing. [Figure 7] FIG. 5 is a box plot showing the variation in GSI for sea urchins fed the diet shown in FIG. 4 and sea urchins fed salted wakame seaweed after 20 months of rearing. [Figure 8] 5 is a graph showing the results of a color analysis of L* (brightness) in the L*a*b* color space of each gonad of sea urchins fed the feed shown in FIG. 4 and sea urchins fed salted wakame seaweed. [Figure 9] 5 is a graph showing the results of a* (red color) analysis in the L*a*b* color space of the gonads of sea urchins fed the feed shown in FIG. 4 and sea urchins fed salted wakame seaweed. [Figure 10] The graph shows the average values ​​of the color analysis using the L*a*b* color space of the gonads of sea urchins fed the diet shown in Figure 4 and sea urchins fed salted wakame seaweed after being raised for approximately 20 months. [Figure 11] This is a photograph showing one gonad from each sea urchin fed with seaweed and one from each sea urchin fed with the diet shown in Figure 4, with the gonads of the sea urchin fed with seaweed on the left and the gonads of the sea urchin fed with the diet shown in Figure 4 on the right. [Figure 12] 5 is a flowchart showing the steps of the method for producing the feed shown in FIG. 4. [Figure 13] FIG. 10 is a perspective view showing the outline of the external configuration of a feed according to another modified example of the present invention. [Figure 14] FIG. 14 is a plan view showing the state inside the breeding tank when the feed shown in FIG. 13 is fed to sea urchins. DETAILED DESCRIPTION OF THE INVENTION

[0056] Hereinafter, one embodiment of the method for producing sea urchins, the feed to be given to sea urchins, the method for producing the feed to be given to sea urchins, and the method for rearing, cultivating, storing, or transporting sea urchins according to the present invention will be described with reference to the drawings. Fig. 1 is a longitudinal cross-sectional view showing a schematic outline of the configuration of a sea urchin rearing system 100 used in the method for producing sea urchins U according to the present invention. This sea urchin rearing system 100 is a facility for rearing sea urchins U (for example, purple sea urchins, northern purple sea urchins, Pacific sea urchins, Siberian sea urchins, or red sea urchins).

[0057] (Configuration of sea urchin rearing system 100) The sea urchin rearing system 100 includes a rearing tank 101. The rearing tank 101 is an aquarium for rearing a plurality of sea urchins U that have transitioned to a benthic lifestyle, and is constructed by forming an FRP (fiber reinforced plastic) material into a box shape that is rectangular in plan view, has an opening at the top, and has a predetermined depth. The size and depth of the rearing tank 101 in plan view are not particularly limited, but in this embodiment, it is formed to be approximately 1 m long, 4 m wide, and 1.5 m high, and the rearing tank 101 is filled with rearing water W to a depth of approximately 1 meter. In this embodiment, the rearing tank 101 is installed in a building on land.

[0058] The inner wall surface of this breeding tank 101 is colored blue to make it easier to see the sea urchins U, the excrement of the sea urchins U, or the feed F given to the sea urchins U in the breeding tank 101. A plurality of breeding cages 102 are housed in this breeding tank 101.

[0059] The breeding cage 102 is a breeding container for separately housing multiple sea urchins U, and is formed from a resin material (such as polypropylene) in the shape of a rectangular box in plan view, with an opening at the top and a predetermined depth. In this embodiment, as shown in Fig. 2, the breeding cage 102 is approximately 40 cm long, 60 cm wide, and 30 cm high in plan view, and is configured with multiple through-holes on the four sides and bottom to allow breeding water W to pass through.

[0060] Three breeding cages 102 are arranged in a row in the longitudinal direction within the breeding tank 101. In this case, each breeding cage 102 is installed in a state in which it is suspended from a rod-shaped installation member 103 that is suspended in the short direction of the breeding tank 101 above the opening of the breeding tank 101. In this case, each breeding cage 102 is installed in the breeding tank 101 with its opening exposed above the water surface.

[0061] In addition, a water intake pipe 104 is provided at one end (right side in the figure) of the breeding tank 101 in the longitudinal direction, and a water supply pipe 107 is provided at the other end (left side in the figure).

[0062] The water intake pipe 104 is a pipe that sucks in some of the breeding water W in the breeding tank 101 and leads it to the purification tank 105, and is provided near the bottom of the breeding tank 101. The purification tank 105 is a mechanical device that filters and sterilizes the breeding water W taken in by the water intake pipe 104 to purify it. The breeding water W purified by this purification tank 105 is returned to the breeding tank 101 via a water supply pipe 107 by a water pump 106.

[0063] The sea urchin rearing system 100 also includes other equipment (not shown) that is generally required for rearing sea urchins U, such as a drainage pipe that keeps the water level of the rearing water W in the rearing tank 101 constant, an aeration system that supplies oxygen to both the rearing tank 101 and the septic tank 105, a heating and cooling system that keeps the temperature of the rearing water W constant, and devices that detect the salinity, pH, temperature, and ammonia concentration of the rearing water W. However, because these pieces of equipment are not directly related to the present invention, their description will be omitted.

[0064] (Method of manufacturing feed F given to sea urchin U) Next, a manufacturing process of the feed F to be given to sea urchins U in the production of sea urchins U using the sea urchin rearing system 100 configured as described above will be described. First, as the first step, an operator performs a preparation step, as shown in Fig. 12. This preparation step is a step of preparing raw materials for the feed F and a mold M for shaping the feed F.

[0065] First, the worker prepares the raw materials for the feed F. Specifically, the worker prepares sake lees and a coagulant as the raw materials for the feed F.

[0066] Here, sake lees are the residue remaining after distilling unrefined sake during the production of distilled alcoholic beverages, and are a slurry-like fluid containing solids such as the main ingredients of distilled alcoholic beverages (for example, rice, barley, corn, buckwheat, brown sugar, or sweet potato) or koji. In this embodiment, the worker uses sake lees that are generated when shochu, which is made from barley, is produced.

[0067] A coagulant is a substance that solidifies a liquid, sol, or slurry-like fluid. Examples of coagulants that can be used include agar, sodium alginate, carrageenan, and gelatin. In this embodiment, the worker uses powdered agar as the coagulant. This agar is a coagulant made from red algae such as Gelidium or Gracilaria, and has the property of dissolving in the object when the object's temperature is approximately 80°C or higher and beginning to solidify at approximately 30°C to 40°C.

[0068] In this embodiment, the worker prepares 1000 ml of sake lees and 1% (10 g in this embodiment) of agar by weight of feed F per kg of feed F to be produced. In other words, feed F contains the most sake lees, and sake lees is the main ingredient.

[0069] Next, the worker prepares a mold M for shaping the feed F. Specifically, the worker prepares a mold M made of metal (e.g., steel) or resin (e.g., polypropylene or silicone) formed into a container-like shape with a bottom and an open top. In this embodiment, the worker prepares a mold M formed with multiple rows of depressions, each about 3 cm long, 4 cm wide, and 3 cm deep in a plan view, arranged in the left-right and up-down directions in a plan view, as shown in FIG. 3. This allows the worker to simultaneously produce multiple (12 in this embodiment) block-shaped feed F, each about 2 cm long, 3 cm wide, and 3 cm deep in a plan view, as shown in FIG. 4.

[0070] Next, the worker performs the second step, a sake lees mixture production step. This sake lees mixture production step is a step in which a sake lees mixture is produced by dissolving a coagulant in boiled sake lees using the raw materials of feed F prepared in the preparation step. This sake lees mixture production step is carried out by the worker by carrying out the following sub-steps 1 to 3.

[0071] Substep 1: First, the worker heats the sake lees to a boil. Specifically, the worker places the sake lees in a pot and heats it until the sake lees boil. Sub-step 2: Next, the worker adds a coagulant to the boiling sake lees and mixes them together. Specifically, the worker adds agar as a coagulant little by little while stirring the sake lees while maintaining the boiling state of the sake lees in sub-step 1 by heating. This allows the worker to dissolve the agar in the sake lees while preventing the agar from solidifying without dissolving (forming lumps) within the sake lees. Sub-step 3: Next, the worker heats the sake lees mixed with agar for a predetermined time. Specifically, the worker heats the sake lees mixed with agar until the agar in the sake lees is sufficiently dissolved. This allows the worker to produce a sake lees mixture in which the agar is sufficiently dissolved in the sake lees.

[0072] Next, the worker performs the third and fourth steps, a solidification step and a color adjustment step, respectively. The solidification step in this third step is a step of solidifying the fluid sake lees mixture. Here, solidification includes not only solidifying the fluid sake lees mixture until it becomes a rigid body that does not elastically deform, but also solidifying it to the extent that it maintains a predetermined shape while allowing elastic or plastic deformation (for example, into a jelly-like state).

[0073] The color adjustment step in this fourth step is a step of adjusting the color of the sake lees mixture to a color other than whitish. Here, whitish colors refer to pure white, grays with high brightness, and colors obtained by adding white to the most saturated color among the hues of chromatic colors (i.e., pure colors), or lighter, lighter colors obtained by adding gray to pure colors (i.e., intermediate colors). These third and fourth steps will be described together in this embodiment because some steps are common to both steps.

[0074] First, the worker pours the hot sake lees mixture into mold M lined with plastic wrap to cool the sake lees mixture (i.e., removes the heat). By pouring the sake lees mixture into mold M lined with plastic wrap in this way, the worker can easily remove the solidified sake lees mixture from mold M. The worker may also omit the step of lining mold M with plastic wrap and pour the sake lees mixture directly into mold M.

[0075] In the process of pouring the sake lees mixture into mold M, the worker pours the fluid sake lees mixture produced in sub-step 3 into mold M as is, without adjusting the pH of the fluid sake lees mixture. The shochu lees used in this embodiment are generally known to have acidic properties. In other words, in this embodiment, the worker pours the acidic sake lees mixture into mold M without processing it.

[0076] Next, the worker covers the opening of the mold M with plastic wrap over the mold M into which the sake lees mixture has been poured. This allows the worker to reduce the drying of the sake lees mixture. Note that in this solidification step, the worker can employ other methods to prevent the sake lees mixture from drying out. For example, the worker may cover the mold M after pouring the sake lees mixture into it. The worker may also omit the step of covering the mold M with plastic wrap.

[0077] Next, the worker places mold M in a freezer and cools it until the sake lees mixture is frozen. During the freezing process of freezing this sake lees mixture, the fluid sake lees mixture solidifies into a jelly-like state, and then solidifies into a rigid body through freezing. This allows the worker to shape and solidify the sake lees mixture into a block. This freezing process of freezing the sake lees mixture constitutes a solidification process of solidifying the fluid sake lees mixture, but also constitutes the color adjustment process in the fourth process.

[0078] That is, as described above, the color adjustment step in step 4 is a step of adjusting the color of the sake lees mixture to a color other than whitish. In this embodiment, however, this freezing step also adjusts the color of the sake lees mixture to a color other than whitish by discoloring the surface of the sake lees mixture. This is based on the inventor's experiments, which found that freezing a fluid sake lees mixture can change the surface color of the sake lees mixture to a brownish color other than whitish. In this case, the longer the freezing time, the more the sake lees mixture can be discolored to a brownish color.

[0079] Next, the worker performs the thawing step as the fifth step. This thawing step is a step of thawing the frozen sake lees mixture. Specifically, the worker removes the mold M from the freezing device, then removes the block-shaped sake lees mixture (hereinafter also referred to as the "sake lees block") from the mold M and returns it to the jelly-like solidified state it was in before freezing (so-called natural thawing). In this way, the worker can thaw the frozen sake lees mixture and obtain a sake lees mixture solidified into a jelly-like state.

[0080] The worker can also thaw the frozen sake lees mixture in the mold M and then remove the jelly-like solidified sake lees mixture from the mold M. The worker can also use a method other than natural thawing to thaw the frozen sake lees mixture. For example, the worker can thaw the frozen sake lees mixture by immersing it in the rearing water W. This allows the worker to thaw the frozen sake lees mixture more quickly than natural thawing and produce feed F at a temperature close to the temperature of the rearing water W.

[0081] As a result, the worker can produce feed F that allows efficient production of sea urchin U. In this case, feed F can be fed to sea urchin U not only when producing sea urchin U but also when raising, cultivating, storing, or transporting sea urchin U.

[0082] (Sea Urchin Production) Next, a method for producing sea urchin U using the sea urchin rearing system 100 configured as described above and the feed F produced by the production method will be described. First, a producer who produces sea urchin U fills the rearing tank 101 with rearing water W and operates the septic tank 105 and the water pump 106 to prepare the rearing environment (water quality, water temperature, salinity, etc.) in the rearing tank 101 to an environment suitable for rearing sea urchin U. This rearing environment for sea urchin U may be a commonly known rearing environment for rearing sea urchin U.

[0083] Next, the producer prepares the rearing cages 102 and the installation structures 103. In this embodiment, the producer prepares three rearing cages 102 and three installation structures 103. Next, the worker installs the rearing cages 102 in the rearing tank 101 using the installation structures 103. Specifically, the producer can install the rearing cages 102 in the rearing tank 101 using the installation structures 103 by suspending the installation structures 103 from which the rearing cages 102 are hung across the top surface of the rearing tank 101 in the short direction. In this case, the installation position of the rearing cages 102 is adjusted to a height where the opening is exposed above the water surface.

[0084] Next, the producer places sea urchin U in the rearing cage 102. In this case, the producer places at least one juvenile sea urchin (sea urchin U) that has been artificially hatched and / or caught in natural waters and has an underdeveloped gonad into the rearing cage 102. Here, "underdeveloped gonads" refers to a state in which the gonads have not yet developed until about one year has passed since the larvae of sea urchin U hatched from the fertilized egg. In this embodiment, juvenile sea urchins (sea urchin U) that are in their metamorphosis and benthic life stage from about two months after hatching until about one year after hatching, before the development of the gonads begins, are used. Note that the producer can place not only sea urchins U of the same species but also different species of sea urchin U in the same or different rearing cages 102.

[0085] Next, the producer feeds the sea urchins U in the rearing cage 102. Specifically, the producer pours the feed F produced by the above-described production method into the rearing cage 102. In this way, the producer pours the feed F that has been thawed in the thawing process, and therefore it is possible to prevent the temperature of the rearing water W from dropping when feeding. In this case, the feed F poured into the rearing cage 102 sinks to the bottom of the rearing cage 102. The feed F may be produced by the producer himself, but it goes without saying that it may also be purchased from another party.

[0086] At this time, the sea urchins U in the rearing cage 102 into which the feed F has been added eat the feed F that has settled to the bottom of the rearing cage 102, as shown in Figure 2. In this case, the producer can monitor the amount of food eaten by the sea urchins U and, if necessary, feed them additional fresh feed F.

[0087] Next, the producer raises the sea urchins U by feeding them with feed F until the gonads of the sea urchins U turn white and / or the GSI exceeds 8%. The time, frequency, and duration of feeding the sea urchins U are selected appropriately depending on the type, age, or size of the sea urchins U. The gonad whitening or GSI of the sea urchins U can be confirmed by sampling a portion of the sea urchins U being raised. Here, GSI indicates the proportion of gonad weight to the total weight of one individual sea urchin U, and is expressed in percent (%).

[0088] Here, the results of three rearing experiments conducted by the present inventor will be described. First, the present inventor conducted a first experiment to confirm the effectiveness of feed F according to the present invention as a feed for sea urchin U. Specifically, in the first rearing experiment, the present inventor placed eight rearing cages 102 in two rearing tanks 101, and housed 25 juvenile red sea urchins (sea urchin U) that were one year old after hatching in each rearing cage 102. The inventor then conducted an experiment to compare the growth rates of sea urchin U between a Sargassum group (four rearing cages 102) in which the sea urchins were reared on only Sargassum, a common feed for sea urchin U, and a feed F1 group (the remaining four rearing cages 102) in which the sea urchins were reared on only feed F according to the present invention.

[0089] In this case, the inventors reared sea urchins U housed in the Sargassum spp. and F1 feed zones for seven months at the same time, and evaluated the growth of 20 sea urchins U randomly selected from each zone each month by measuring the shell diameter. Here, the shell diameter of sea urchin U refers to the length of the widest part of the shell of sea urchin U in a planar view, when the anus of sea urchin U at the top of sea urchin U is viewed from directly above.

[0090] Figure 5 shows the average monthly shell diameters of sea urchin U selected from each of the above-mentioned areas, with the vertical axis representing the shell diameter (mm) of sea urchin U and the horizontal axis representing the month of the feeding period. The line with black circles is a line graph connecting the monthly shell diameter values ​​of sea urchin U reared in the diet F1 area, and the line with white circles is a line graph connecting the monthly shell diameter values ​​of sea urchin U reared in the Sargassum area.

[0091] As a result of this first rearing experiment, sea urchin U reared on diet F1 increased in shell diameter at approximately the same rate of growth as sea urchin U reared on the Sargassum spp. In other words, diet F was equivalent to a general diet for sea urchin U in terms of the rate of growth of sea urchin U, and it was confirmed that diet F is effective as a feed for sea urchin U.

[0092] On the other hand, at sea urchin U production sites, it is known that some feeds for sea urchin U are capable of increasing the size of sea urchin U, but are not effective in developing the gonads (edible parts) of sea urchin U. Therefore, the present inventors conducted a second experiment to confirm the effectiveness of feed F according to the present invention as a feed for developing the gonads of sea urchin U.

[0093] Specifically, as a second rearing experiment, the inventor set up eight rearing cages 102 in two rearing tanks 101, and housed 25 juvenile red sea urchins (sea urchin U) that were one year old after hatching and had a GSI of less than 8% in each rearing cage 102.The inventor then conducted an experiment to compare the growth rate of the gonads of sea urchin U in a first salted wakame area (four rearing cages 102) in which the sea urchins were reared on only salted wakame (salted wakame with the salt washed away), which is a common feed for sea urchin U, and a feed F2 area (the remaining four rearing cages 102) in which the sea urchins were reared on only feed F according to the present invention.

[0094] In this case, the inventor reared the sea urchins U housed in the first salted wakame area and the feed F2 area for seven months at the same time, and then measured the shell diameter, weight, and gonad weight (gonad weight) of five individuals randomly selected from each area, and calculated the gonad weight index (GSI).

[0095] Figure 6 shows the average values ​​of shell diameter (mm), weight (g), gonad weight (g), and GSI (%) for sea urchin U selected from each of the above plots. Figure 7 shows the variation in the GSI values ​​for each individual sea urchin U selected from each of the above plots, with the vertical axis representing GSI (%) and the horizontal axis representing the type of food fed to sea urchin U.

[0096] The results of this second rearing experiment showed that the GSI of sea urchin U reared in the F2 diet exceeded 8%, the standard for the harvesting of sea urchin U, and the gonads of sea urchin U reared in the first salted wakame diet increased in a shorter period of time, allowing them to grow to a size that could be harvested earlier. In other words, because diet F can grow the gonads of sea urchin U in a shorter period of time than the general sea urchin U diet, it was confirmed that diet F is more effective than the general sea urchin U diet as a feed for developing the gonads of sea urchin U.

[0097] In addition, in the second rearing experiment, the inventor reared sea urchins U housed in the first salted wakame area and the feed F2 area for the same period of seven months, and then analyzed the color of the gonads of five sea urchins U randomly selected from each area.

[0098] 8 and 9 show the results of color analysis of L* (brightness) and a* (redness) in the L*a*b* color space for each gonad of sea urchin U selected from each of the above-mentioned groups, with the black circles representing data for sea urchin U reared in the F2 diet group and the white circles representing data for sea urchin U reared in the first salted wakame group. As a result of this second rearing experiment, the gonads of sea urchin U reared in the F2 diet group had an a* value of 5 or less and an L* value of 65 or more, and were a light reddish-white color, which was closer to white than the color of the gonads of sea urchin U reared in the first salted wakame group.

[0099] Furthermore, the present inventors conducted a third experiment to confirm how feeding Feed F according to the present invention affects the color tone of the gonads of sea urchins U.

[0100] Specifically, as a third rearing experiment, the inventor set up eight rearing cages 102 in two rearing tanks 101, and housed 25 juvenile red sea urchins (sea urchin U) that were one year old after hatching in each rearing cage 102. An experiment was conducted to compare the color of the gonads of sea urchin U in a second salted wakame area (four rearing cages 102) where the sea urchins were reared only on salted wakame (salted wakame with the salt washed off), which is a common feed for sea urchin U, and a feed F3 area (the remaining four rearing cages 102) where the sea urchins were reared only on feed F according to the present invention.

[0101] In this case, the inventor reared the sea urchins U housed in the second salted wakame area and the feed F3 area for approximately 20 months, and then analyzed the color tone of the gonads of three sea urchins U randomly selected from the second salted wakame area and six sea urchins U randomly selected from the feed F3 area.

[0102] Figure 10 shows the average values ​​of color analysis using the L*a*b* color space for the gonads of sea urchin U selected from each of the above-mentioned groups. The results of this third rearing experiment showed that the color of the gonads of sea urchin U reared on the F3 diet was approximately one-quarter of the color of the gonads of sea urchin U reared on the second salted wakame group in both a* (toward red) and b* (toward yellow), indicating very low a* and b* values. Furthermore, as in the second rearing experiment, the gonads of sea urchin U reared on the F3 diet showed a color with a very high L* value.

[0103] Therefore, the results of the color analysis in the second and third rearing experiments confirmed that the gonads of sea urchin U, which were reared by feeding diet F to juvenile sea urchins one year after hatching, exhibited a white color (right side of the figure) with higher brightness and lower chromaticity than sea urchin U (left side of the figure) reared by feeding general sea urchin U diet, as shown in Figure 11.

[0104] In Figure 11, because the color photograph image has been processed into grayscale, it is difficult to distinguish the difference in color tone between the gonads of sea urchin U raised on general sea urchin U feed and the gonads of sea urchin U raised on feed F. However, when comparing the color tone within dashed circle A (gonads of sea urchin U raised on general sea urchin U feed) shown in Figure 11 with the color tone within dashed circle B (gonads of sea urchin U raised on feed F), it can be confirmed that the gonad within dashed circle B is whiter than the gonad within dashed circle A.

[0105] The present inventors also conducted a similar experiment to the third rearing experiment on sea urchin U, whose gonads were fully developed. As a result of this experiment, sea urchin U, whose gonads were fully developed, was reared by feeding it with feed F. F It was confirmed that the gonads of sea urchins U with bleached gonads or with only a low degree of bleaching. The inventors also conducted an experiment in which sea urchins U with bleached gonads and fully developed were fed pumpkin for 60 days. As a result, it was confirmed that the color of the gonads of sea urchins U with bleached gonads and fully developed gonads changed to a yellowish color.

[0106] From the above experimental results, producers can produce sea urchins U with white gonads by feeding feed F to sea urchins U with underdeveloped gonads. In this case, producers can conduct experiments in advance to determine the rearing period and / or the amount of feed required until the gonads turn white and / or until a sufficient GSI is reached, and can specify the timing for landing (harvesting) the sea urchins U from the rearing tank 101 by waiting for a predetermined period of time and / or feeding a predetermined amount of food. This allows producers to avoid losses due to sampling of the sea urchins U and harvest the sea urchins U when the gonads turn white or the GSI exceeds 8%.

[0107] Sea urchin U produced in this way can be used in various situations as shown below. Specifically, sea urchin U with whitish gonads can be used as a new food ingredient with white edible parts. Currently, most of the edible parts of sea urchin U are reddish yellow (orange), yellow, or light yellow, so sea urchin U with whitish gonads is extremely unique. In this way, sea urchin U with whitish gonads has value as a new food ingredient because its edible parts have unique characteristics.

[0108] Furthermore, sea urchins U with whitish gonads can be used as samples for experiments to clarify the mechanism of gonad coloration in sea urchins U or the relationship between gonad color change and the feed fed to sea urchins U. In this case, in order to use sea urchins U with whitish gonads as samples for the experiments, the sea urchins U with whitish gonads need to be alive. In this regard, sea urchins U produced by the above-mentioned production method have a whitish gonad color and can be landed (harvested) in the same state without being split, making them useful as samples in the research field.

[0109] Furthermore, in the first to third rearing experiments, it was observed that sea urchin U, which was reared on feed F, excreted whitish feces. From this, as a method for producing sea urchin U, producers can check the feeding status of sea urchin U by distinguishing between feed F and the feces of sea urchin U based on their colors after feeding them feed F, and can prepare an environment suitable for sea urchin U based on the feeding status.

[0110] Specifically, because the producer can distinguish between the feed F, which is a color other than whitish (in this embodiment, brownish-red), and the excrement of the sea urchin U, which is whitish, by their colors, the producer can confirm the feeding status of the sea urchin U, such as whether or not the sea urchin U has ingested the feed F, how much feed F it has ingested, and which sea urchin U has ingested the feed F. Then, based on the confirmed feeding status, the producer can adjust the feeding method of the feed F, such as the amount, timing, frequency, and position of the feed F, and the shape of the feed F, or the rearing environment (water quality, water temperature, salinity, etc.) to a state suitable for the sea urchin U.

[0111] As can be understood from the above operation description, according to the above embodiment, in the method for producing sea urchin U, the feed F fed to young sea urchins (sea urchin U) is a feed that reduces the environmental impact and contains sake lees that would otherwise be subject to disposal. Therefore, sea urchin U can be produced using environmentally friendly feed F, and the commercial value of sea urchin U can be improved as a highly sustainable sea urchin U.

[0112] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the object of the present invention.

[0113] For example, in the above embodiment, the method for producing sea urchin U is configured to feed sea urchin U with feed F to produce sea urchin U with whitish gonads. This method for producing sea urchin U can produce extremely unique sea urchin U with whitish gonads, and since this sea urchin U has value as a new food or useful value as a sample, the commercial value or utility value of the sea urchin U can be improved. However, producers may also produce sea urchin U with normal gonads by feeding the sea urchin U with feed F to the extent that the gonads do not turn white. This allows producers to produce sea urchin U using feed F containing sake lees, which would otherwise be subject to disposal, while reducing the environmental impact, thereby adding value as a highly sustainable sea urchin U and improving the commercial value of the sea urchin U.

[0114] In the above embodiment, the feed F contains distilled sake lees. However, the feed F may also contain sake lees that are generated when unrefined sake mash is squeezed during the production of brewed alcoholic beverages, such as sake, beer, and wine.

[0115] Furthermore, in the above embodiment, feed F was prepared using 1000 ml of sake lees, which is approximately 99% of the weight of feed F, as the amount of sake lees that can whiten the gonads of sea urchin U. However, the blending ratio of sake lees in feed F is not limited to the above ratio, as long as it is an amount that can whiten the gonads of sea urchin U. In this case, the content of sake lees in feed F should be 50% or more, preferably 60% or more, more preferably 70% or more, more preferably 80% or more, and more preferably 90% or more.

[0116] Furthermore, in the above embodiment, the feed F is configured to contain an amount of sake lees that is capable of whitening the gonads of the sea urchins U. This allows the feed F to whiten the gonads of the sea urchins U that are fed this feed F. However, since the feed F is only required to contain at least sake lees, it may also be configured with an amount of sake lees that is less than the amount that is capable of whitening the gonads of the sea urchins U. For example, the feed F may be configured to contain 40% sake lees by weight of the feed F.

[0117] In the above embodiment, feed F was prepared by using 10 g of agar for 1000 ml of sake lees. However, the blending ratio of sake lees and coagulant in feed F is appropriately selected depending on the type, age, or size of sea urchin U, and is not limited to the above amounts. Therefore, feed F may be prepared by using, for example, 20 to 30 g of agar for 1000 ml of sake lees.

[0118] In the above embodiment, the feed F is formed into a block shape. However, the feed F may be formed into a shape other than a block. For example, the feed F may be formed into a sheet, plate, or strip shape, as shown in FIG. 13.

[0119] In this case, the worker producing the feed F first prepares a mold M (not shown) for forming the feed F into a sheet, plate, or strip. Specifically, the worker prepares a mold M made of metal (e.g., steel) or resin (e.g., polypropylene or silicone) material shaped like a shallow container (tray) with an opening at the top. The worker can then produce the feed F formed into a sheet, plate, or strip using the same manufacturing process as in the above embodiment. In this way, as shown in FIG. 14, multiple sea urchins U can attach to one sheet of feed F, providing an opportunity for many sea urchins U to eat at the same time, increasing the opportunity for each individual to eat and reducing the amount of food waste.

[0120] Specifically, the feed F can be formed into a sheet, plate, or strip shape with at least one side measuring 4 cm or more. In this way, the sea urchins U, which start eating the feed F when they grow to a shell diameter of about 2 cm, can attach at least two of them to one sheet of feed F at the same time, providing an opportunity for multiple sea urchins U to eat the feed F at the same time.

[0121] In addition, feed F has a surface area of ​​20 cm 2 The feed F can be formed into a sheet, plate, or strip shape as described above. In this way, the feed F can be configured so that multiple sea urchins U attach to one sheet of feed F, thereby increasing the opportunities for each sea urchin U to eat, and since the sea urchins U can be positioned without being in close contact with each other, it is possible to prevent them from injuring or cannibalizing each other. Furthermore, the feed F formed in a flat shape is easy for the sea urchins U crawling inside the rearing cage 102 to eat, and is in a form that makes it easy for rearers to monitor the sea urchins U.

[0122] Furthermore, by forming the feed F into a sheet, plate, or strip shape, it can be torn by hand into appropriate sizes to facilitate feeding. In this case, the feed F can be torn into sizes according to the shape of the rearing cage 102 in which the sea urchins U are reared or the size of the sea urchins U, and even if the rearing cage 102 is small, the feed F can be provided in a size that is easy to feed or that the sea urchins U can easily eat. Furthermore, the feed F formed into a sheet, plate, or strip shape can also be used for shellfish other than sea urchins U.

[0123] Furthermore, the feed F can be formed into a flexible sheet, plate, or strip shape. This allows the shape of the feed F to be deformed to fit the shape of the area where the feed F is provided, making it easy to feed the sea urchins U even when the rearing cage 102 is small, and preventing the range of movement of the sea urchins U within the rearing cage 102 from becoming narrower.

[0124] Furthermore, the feed F can be formed into a plate-like shape that does not have flexibility like a rigid body. In this way, the feed F can be set upright or suspended in the rearing cage 102, and the sea urchins U can be attached to both sides of the plate-like feed F, thereby providing an opportunity for more sea urchins U to eat at the same time.

[0125] Furthermore, the feed F can be formed into a flexible and pliable sheet, plate, or strip shape. In this way, the sea urchins U can be easily removed from the rearing tank 101 without directly touching them by simply pulling up the feed F with the sea urchins U attached from the rearing cage 102. Here, "flexible" refers to a softness that does not have enough stiffness to prevent the feed F from maintaining its horizontal or upright positions. These sheet, plate, or strip-shaped feed F can be placed in a horizontal position within the rearing cage 102, or can be placed in a vertical position by leaning it against something or hanging it up.

[0126] In the above embodiment, the feed F was formed into a block shape with a length of about 2 cm, a width of about 3 cm, and a height of about 3 cm in plan view. 2 According to this, the feed F can increase the chances of each sea urchin U feeding by attaching multiple sea urchins U to one feed F, and can also prevent the sea urchins U from hurting or cannibalizing each other because they can be positioned without being in close contact with each other. However, the feed F has a surface area of ​​20 cm 2 It can also be formed and configured to be less than this.

[0127] Furthermore, in the above embodiment, the worker used the mold M to shape the feed F into a block of a size to be fed to the sea urchin U. However, the worker can shape the feed F into a desired shape by forming the feed F into a block larger than the size to be fed to the sea urchin U, and then cutting this block of feed F into an appropriate size for feeding to the sea urchin U. This forming method can also be adopted when the worker shapes the feed F into a shape other than a block, for example, into a sheet, plate, or strip.

[0128] Furthermore, in the above embodiment, the feed F is composed of a brownish-red color. However, the feed F can also be composed of a whitish color. In this case, since the feed F is composed of a whitish color, the feed F can be easily distinguished from the sea urchin U, which is black, green, or reddish-brown, by these colors. In other words, according to the present invention, it is easier to grasp at a glance the number and position of the sea urchins U, whether or not the sea urchins U are ingesting the feed F, and the amount of food intake of the sea urchins U, compared to when the color of the feed F is a color other than whitish. This is particularly effective for juvenile sea urchins (sea urchins U), which are smaller in size and therefore more difficult to distinguish from the feed F than the grown sea urchins U.

[0129] Furthermore, in the above embodiment, the feed F contains sake lees in an amount sufficient to whiten the feces of the sea urchin U and is constituted of a brownish-red color other than whitish. According to this, since the feed F contains sake lees in an amount sufficient to whiten the feces of the sea urchin U and is constituted of a brownish-red color, the whitened feces of the sea urchin U and the feed F can be easily distinguished by their colors, and it is easier to determine at a glance whether the sea urchin U has ingested the feed F or the amount of the sea urchin U that has ingested it, compared to when the color of the feed F is whitish. However, the color of the feed F is not limited to brownish-red, as long as it is constituted of a color that can be easily distinguished from the whitish feces of the sea urchin U, specifically a color other than whitish, such as black, green, or navy blue.

[0130] In the above embodiment, feed F is prepared using agar as a coagulant. However, the coagulant used in feed F is not limited to agar, and for example, sodium alginate, carrageenan, or gelatin can be used. When using sodium alginate, the worker producing feed F first gradually adds 10 g (1% of the weight of feed F) of sodium alginate to 1000 ml of sake lees to create a mixture in which the sodium alginate is completely dissolved. Next, the worker prepares a mold M for forming feed F, pours the mixture into the mold M, and then places it in a refrigerator to cool. Next, the worker dissolves 200 g of calcium chloride in 1800 ml of water to create an approximately 10% calcium chloride aqueous solution. Next, the worker immerses the cooled mixture in the calcium chloride aqueous solution to solidify it. In this way, the worker can produce feed F using sodium alginate as a coagulant.

[0131] In the above embodiment, feed F is made using only the distilled liquor lees (barley shochu lees) and agar. This allows feed F to be produced inexpensively by reducing the cost of raw materials. However, feed F can also be made by adding other ingredients such as seaweed, vegetables (e.g., pumpkin or cabbage), or fruits (e.g., apples or grapes) to the distilled liquor lees and agar.

[0132] Furthermore, in the above embodiment, the manufacturing method of feed F is configured to include a color adjustment step of adjusting the color of feed F to a color other than whitish. In this way, the manufacturing method of feed F can manufacture feed F configured to have a color that can be easily distinguished from the whitish feces of sea urchin U. However, the manufacturing method of feed F can also be configured to omit the color adjustment step.

[0133] Specifically, a method for producing feed F that omits the color adjustment step can be configured to include the sake lees mixture production step and the solidification step of solidifying the sake lees mixture into a jelly-like form in the above embodiment. This production method does not involve adjusting the color of feed F, so the color of the produced feed F is a color that is naturally acquired during the production process. In this case, feed F produced without color adjustment can be fed to sea urchin U during the production, breeding, cultivation, storage, or transportation of sea urchin U.

[0134] Furthermore, in the above embodiment, the color adjustment step is configured to adjust the color of the sake lees mixture to a color other than whitish by changing the color of the surface of the sake lees mixture through the freezing step. This allows the method for producing feed F to easily adjust the color of the sake lees mixture to a color other than whitish. However, the color adjustment step is not limited to the freezing step, as long as it can adjust the color of the sake lees mixture to a color other than whitish. Specifically, the color adjustment step can be performed by various methods, such as adding a coloring additive to the sake lees mixture, immersing the sake lees mixture in a dye, or coating the surface of the sake lees mixture with a colored substance. In other words, the color adjustment step includes adjusting the color of the surface or outer layer of the sake lees mixture and adjusting the color of the interior of the sake lees mixture.

[0135] In the above embodiment, the color adjustment step is configured to adjust the color by freezing the sake lees mixture solidified into a jelly-like state to change the color of the sake lees mixture. However, the timing of performing the color adjustment step is not limited to when the sake lees mixture is frozen, and may include the timing before or after the sake lees mixture is frozen. In other words, the order in which the freezing step and the color adjustment step are performed does not matter.

[0136] Furthermore, in the above embodiment, the solidification step is configured to solidify the fluid sake lees mixture into a jelly-like state during the freezing step. However, the solidification step is not limited to a freezing step, as long as it can solidify the fluid sake lees mixture into a jelly-like state. Specifically, the solidification step can be performed by pouring the fluid sake lees mixture into a mold M and then leaving the mold M in an appropriate location at a temperature at which the coagulant begins to solidify (for example, a temperature of approximately 30°C to 40°C for agar), thereby solidifying the fluid sake lees mixture into a jelly-like state. Furthermore, the solidification step can be performed by pouring the fluid sake lees mixture into the mold M and then placing the mold M in a refrigerator to cool it, thereby solidifying the fluid sake lees mixture into a jelly-like state more quickly.

[0137] Furthermore, in the above embodiment, the method for producing feed F includes a thawing step of thawing the frozen sake lees mixture. This makes it possible to produce feed F that prevents the temperature of the rearing water W from decreasing during feeding, compared to when the sake lees mixture is fed to the sea urchins U while still frozen. However, the method for producing feed F can also be configured to omit the thawing step.

[0138] Specifically, a method for producing the feed F without the thawing step can be configured to include the sake lees mixture production step, solidification step, color adjustment step, and freezing step in the above embodiment. In this case, the producer can remove the feed F from the freezer immediately before feeding it to the sea urchins U and place the frozen feed F into the rearing cage 102 to feed it to the sea urchins U.

[0139] In the above embodiment, the sea urchin rearing system 100 is configured as an aquarium in which the rearing cage 102 is installed in the rearing tank 101. However, the sea urchin rearing system 100 can also be configured so that the rearing cage 102 is omitted and the sea urchin U is directly placed in the rearing tank 101 and reared.

[0140] Furthermore, in the above embodiment, the sea urchin rearing system 100 is configured by installing the rearing tank 101 on land. However, the sea urchin rearing system 100 can also be configured by installing a net or a fish preserve on the sea surface, or a cage installed underwater. For example, the sea urchin rearing system 100 can be configured by installing a net (not shown) on the sea surface that extends to the seabed to form a compartment for housing the sea urchins U. The sea urchin rearing system 100 can also be configured by installing a cage (not shown) for housing the sea urchins U on or underwater. In these cases, the producer periodically supplies feed F to the compartment or cage for housing the sea urchins U.

[0141] Furthermore, in the above embodiment, the producer produced sea urchin U using the sea urchin rearing system 100. However, the sea urchin rearing system 100 can be omitted in the method for producing sea urchin U. In this case, the producer can produce sea urchins by spreading feed F in the natural ocean. Here, the place where feed F is spread may be, for example, an ocean area where sea urchin U already lives. According to this, in the sea urchin production method, it is possible to omit equipment for producing sea urchin U or transporting sea urchin U to said equipment, thereby improving the commercial value of sea urchins as highly sustainable sea urchins produced with reduced environmental impact. Furthermore, producers can attract sea urchin U to an ocean area where sea urchin U has not been confirmed to live by spreading feed F in that area. [Explanation of symbols]

[0142] F...feed, M...type, U...Sea urchin, U F ...sea urchin, W: breeding water, 100... sea urchin breeding system, 101... breeding tank, 102... breeding cage, 103... erection body, 104...water intake pipe, 105...septic tank, 106...water supply pump, 107...water supply pipe.

Claims

1. A method for producing sea urchin, comprising: A method for producing sea urchins, characterized by feeding sea urchins with underdeveloped gonads with feed containing sake lees.

2. The method for producing sea urchin according to claim 1, A method for producing sea urchins, characterized in that the gonads are whitened by feeding the feed.

3. A method for producing sea urchin, comprising: A method for producing sea urchins, characterized in that the proportion of gonad weight to the total weight of each individual sea urchin is less than 8% by feeding said sea urchins a feed containing sake lees, thereby increasing said proportion to 8% or more.

4. A feed for sea urchins with underdeveloped gonads, A feed characterized by containing sake lees.

5. The feed according to claim 4, The amount of sake lees is: A feed characterized in that the amount is sufficient to whiten the gonads.

6. A feed given to sea urchins, Distiller's lees produced during the distillation process, A feed characterized by containing agar that solidifies the distiller's liquor lees.

7. The feed according to claim 6, A feed characterized by being composed only of the distiller's lees and the agar.

8. The feed according to any one of claims 4 to 6, A feed characterized by having a surface that is white in color.

9. A feed given to sea urchins, The feed contains sake lees in an amount that whitens the sea urchin feces, and has a surface color other than white.

10. The feed according to any one of claims 4, 6 and 9, A feed characterized by being formed in the shape of a sheet or plate.

11. The feed according to claim 10, A feed characterized by being flexible and bendable.

12. The feed according to claim 10, Surface area is 20 cm ２ A feed characterized by the above.

13. The feed according to any one of claims 4, 6 and 9, A feed characterized by being formed in a block shape.

14. The feed according to claim 13, Surface area is 20 cm ２ A feed characterized by the above.

15. A method for raising, cultivating, storing or transporting sea urchins, comprising feeding the sea urchins with the feed according to any one of claims 4, 6 and 9.

16. A method for producing feed for sea urchins, a sake lees mixture producing step of adding a coagulant to sake lees heated to about 80°C or higher to produce a sake lees mixture; and a solidification step of solidifying the sake lees mixture.

17. The method for producing a feed according to claim 16, further comprising: A method for producing a feed, comprising a color adjustment step of adjusting the sake lees mixture to a color other than white.

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