JP2017085903A - Culture apparatus for underwater creatures that live in sandy soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a culture apparatus capable of always keeping clean the whole area of a sand layer which is a habitat environment for underwater creatures such as crustacean that live in sandy soil, and producing high quality underwater creatures that live in sandy soil at a fast growth rate and in high density.SOLUTION: A culture apparatus 100 for underwater creatures that live in sandy soil includes a culture tank 10, and water supply pipes 20 arranged on the bottom of the culture tank 10 at constant intervals, the water supply pipes 20 being provided with jetting ports 21 at constant intervals on the side face.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an aquaculture apparatus for sandy inhabited aquatic organisms.

  Shrimp is a typical sandy habitat shellfish that is used for food in many countries. In particular, prawn (Marsupenaaeus japiconicus) is a representative species of sandy inhabiting crustaceans, and is widely used as a high-class food in Japan. The prawns are nocturnal, dive into the sand during the day, and move out onto the sand for feeding during a limited time during the night.

  The prawn aquaculture technology was established about 50 years ago. In areas such as Japan where there are unsuitable winter seasons, seedlings are usually introduced from around April and May when the water temperature rises, and after about 6 months of growth, the plants are grown for about 6 months before the end of September. To ship. During winter, when growth stops due to a drop in water temperature, no breeding is performed, and during this period, water is drained from the aquaculture pond or aquaculture tank and cleaning is performed. In warm regions where the shrimp can grow even in winter, it is cultivated so that it can be shipped in the winter when the market is in short supply, and it is shipped from around November to around May. During the month of July, clean up the aquaculture pond or aquaculture tank.

The shrimp farming method is roughly divided into two types.
The first method is called the “Setouchi type”, and is a method of replacing pond water using tides in a pond built on the coast. A sand layer with a thickness of about 10 to 20 cm is formed on the bottom of the pond, seawater is applied at a depth of about 2 m, water is changed once a day, and pollutants such as residual food, excrement and molting shells are discharged together with drainage. . When the tide is at low tide, open the sluice to drain and clean the pond. Adjust the tide level and pond height to replace the water so that the optimal water level can be maintained. A filter will be installed at the sluice to prevent shrimp spills and other aquatic life. The Setouchi-style is a culture method that is susceptible to damage from typhoons and storm surges and the weather, but that raises and raises young seedlings of seedlings at a low density and requires relatively little labor.

  The second method is called “pour-off type”, where sand is placed on the bottom of ponds and aquariums on land, fresh sea water pumped up by pumps is used to replace water, and rearing while discharging pollutants It is a method to do. There is no need to construct a dike, etc., and by filtering the supplied seawater with a filter, it is possible to maintain a good water quality and raise the breeding density relatively high. The flow-through method has a high running cost such as electricity and filter for operating the pump, and cannot completely discharge the settled contaminants or the contaminants buried in the sand.

  In addition to the conventional aquaculture method described above, 10-15 cm away from the bottom of the aquarium, a double bottom is provided with a mesh or the like, a sand layer is laid on this double bottom, and seawater is directed from the top to the bottom of the sand layer, There is a so-called flowing water method in which pollutants are discharged by always draining. The flowing water type drains a large amount of water from the central drainage device several times a day, and discharges the accumulated pollutant together with this large amount of drainage. The flowing water type can increase the production volume in a small area compared to the Setouchi type and the pouring type, but it requires a large capacity pump to increase the water conversion rate 3-4 times a day, and the running cost Is expensive.

As described above, the most serious problem of the conventional prawn aquaculture apparatus is that the sand layer, which is the prawn growth environment, is contaminated with contaminants. Contaminants left in the sand layer are decomposed by microorganisms and become harmful substances such as ammonia and hydrogen sulfide. The prawns concentrate on areas where there is little contamination while avoiding the contaminated areas. However, as the prawns concentrate, the contamination progresses in a short period of time. By repeating this, the area with less pollution gradually decreases, and the prawn habitat becomes only a part of the aquaculture tank, and the actual breeding density in the aquaculture tank is the breeding density calculated from the area of the aquaculture tank Higher than. If the breeding density of the prawns becomes high and the growth environment becomes inferior, the stress increases and the growth rate of the prawns decreases, and the prawns are damaged by each other and the quality is lowered. In addition, the unsanitary environment causes diseases such as bacteriosis, mycosis and virosis, causing drowning of prawns and reducing production.
If the breeding density of the prawn is increased in order to increase the production amount, the growth environment is further deteriorated, the disease is likely to occur, the drowning prawn is increased, and the productivity is lowered.
In addition, even when prawns are produced by controlling the breeding density and managing them appropriately, contaminants accumulate in the sand layer of the aquaculture pond or aquaculture tank, and in some cases become sludge and solidify. Therefore, it is necessary to clean up the seawater by completely discharging the breeding seawater before the seeds are introduced in the next fiscal year, digging up the sand layer, exposing it to sunlight and air, washing it with clean seawater, or replacing it with new sand.

In the late 1980s, prawns were cultivated in an amount exceeding 3000 tons per year, but in recent years they are stagnant at around 1600 tons. As described above, this is due to the difficulty of carcass shrimp culture, low disease productivity due to disease, and the high work load that requires manpower.
In contrast to the conventional prawn aquaculture method having such problems, several aquaculture apparatuses or aquaculture methods for efficiently removing contaminants from the sand layer have been proposed.
For example, in Patent Document 1, a discharge port is provided in the center, the surface around the discharge port is a concrete feeding region, a growth region of a sand layer is provided around the discharge port, and a water outlet is provided in the sand layer. An aquaculture tank is disclosed in which a growth area is separated from contamination by bait, and contaminants and the like are prevented from accumulating in the growth sand.
In Patent Document 2, the water layer is covered with a light-shielding house, the brightness is 100 lux or less on the water surface, beneficial bacteria are propagated in the aquarium so that the transparency is 50 cm or less, and nocturnal prawns lurk at the bottom of the aquarium. A growing method without a sand layer is disclosed.
Patent Document 3 discloses an aquaculture system in which a water injection section is provided below a sand layer of a breeding tank that is blocked from the external environment, and strong alkaline seawater is supplied to prevent pathogen propagation.
In Patent Document 4, a sand bed is provided on a water-permeable porous body, external seawater is supplied from below the porous body, and supplied through an annular septic tank provided along the peripheral wall of the circular water tank, An aquaculture device is disclosed in which the circulation mechanism is strengthened in two stages to forcibly mix water to strengthen the swirl flow and move the filth in the water toward the drain pipe provided at the center of the bottom of the circular aquarium.

Japanese Patent Laid-Open No. 61-293325 JP 2006-217895 A JP-A-11-169011 JP 2002-360110 A

  The present invention provides an aquaculture device capable of always producing a high-quality sandy inhabited aquatic organism at a high growth rate at a high density while keeping the entire surface of the sand layer, which is a habitat for sandy aquatic organisms such as crustaceans, clean at all times. .

  In order to grasp the essential problems regarding the cultivation of sandy inhabited aquatic organisms, the present inventors have intensively studied to arrive at the present invention. That is, the present inventors have determined that the main cause of the deterioration of the growth environment is contaminants that remain trapped in the sand layer that is difficult to remove with conventional aquaculture devices and methods, and are trapped in the sand layer. We have developed an aquaculture device that can efficiently release the contaminated material into the water layer, keep the entire sand layer clean and maintain a good growth environment.

The specific configuration is as follows.
1. An aquaculture tank,
Water supply pipes arranged at regular intervals at the bottom of the aquaculture tank;
Have
The aquaculture apparatus for sandy inhabited aquatic organisms, wherein the water supply pipe is provided with spouts on a side surface at a constant pitch.
2. 1. The pitch of the said jet nozzle is smaller than the space | interval of the said water supply piping. The aquaculture device described in 1.
3. The water supply pipe does not have a closed end. Or 2. The aquaculture device described in 1.
4). The jet outlet of the water supply pipe does not face the jet outlet of the adjacent water supply pipe. ~ 3. An aquaculture device according to any one of the above.
5. The spout spouts water in a direction of 15 degrees or more left and right around a normal passing through the spout center. ~ 4. An aquaculture device according to any one of the above.
6). 1. It drains from the center part of the aquaculture tank. ~ 5. An aquaculture device according to any one of the above.
7). 1. It has a swirl flow generator installed around the inner wall of the aquaculture tank. ~ 6. An aquaculture device according to any one of the above.

The aquaculture apparatus of the present invention efficiently disposes contaminants such as residual food, excrement, and molting shells in the sand layer from the entire surface of the sand layer into the water layer by arranging the spout uniformly over the entire bottom surface of the aquaculture tank. Pollutants that are released and suspended in water can be discharged from the aquaculture tank, and generation of toxic substances such as hydrogen sulfide can be suppressed. The entire sand layer can be kept clean, the contaminants can be discharged from the water layer, and the entire sand layer can be kept clean.
With the aquaculture device of the present invention, the entire sand layer can be kept clean, and the entire sand layer can be used as a habitat for sandy aquatic organisms. Sandy inhabited aquatic organisms are not partly concentrated and are evenly distributed over the entire sand layer, and a fast growth rate is achieved with a small amount of feeding. With the aquaculture device of the present invention, prawns can be produced with a low mortality rate and a high aquaculture density, and the production amount per unit area can be greatly increased. The aquaculture apparatus of the present invention can produce high-quality sandy inhabited aquatic organisms with little stress on the sandy inhabited aquatic organisms.
Since the aquaculture apparatus of the present invention has few contaminants remaining in the sand layer, it is possible to reduce the frequency of cleaning and replacement of the sand layer after completion of the culture, and in some cases, it is not necessary to clean and replace the sand layer. The time required to clean the sand layer is short, and in some cases, without further cleaning, the next aquaculture can be started, the operating time of the aquaculture equipment can be increased, and the annual production can be greatly increased. .

By making the pitch of the spouts smaller than the interval between the water supply pipes, water can be uniformly supplied to the entire surface of the sand layer.
By not providing the closed end in the water supply pipe, the pressure loss is reduced as compared with the case where the closed end is provided, and the momentum of the water ejected from each outlet of the water supply pipe can be made uniform.
The jetted water passes through the sand layer and flows out onto the sand, but thickness unevenness and poor purification may occur in the sand layer. It was clarified that one of the causes was the behavior of the water flow in the sand layer, and the positions and shapes of the pipes and jet nozzles were identified. By piping so that the outlets of the adjacent water supply pipes do not face each other, the water jetted from the outlets of the adjacent water supply pipes does not collide, and variation in the flow velocity of the upward water flow that passes through each part of the sand layer is reduced. The thickness of the sand layer does not vary.
By ejecting water in the direction of 15 degrees or more to the left and right around the normal line passing through the center of the ejection port from the ejection port, water can be ejected at a wide angle and water can be supplied to a wide area of the sand layer. .
By draining from the center of the aquaculture tank, the distance from each part of the aquaculture tank to the drainage device can be shortened, and contaminants released from the entire sand layer to the water layer can be efficiently discharged. .
By generating a swirl flow with the swirl flow generator and gently stirring the sand layer, contaminants carried on the surface of the sand layer by the upward water flow and pollutants buried in the sand layer are easily released into the water layer. In addition, the gentle agitation of the sand layer by swirling flow works in the same way as the agitation of sand by natural waves and tides, making the habitat such as prawns closer to the natural environment and reducing the stress of prawns. be able to. At this time, the waste collected from the central part of the culture tank by the swirling flow can be discharged more efficiently by draining from the central part of the culture tank.

The schematic diagram of one Embodiment of the aquaculture apparatus of this invention. The schematic diagram inside the aquaculture apparatus seen from the II direction in FIG. The schematic diagram of the flow of the water from the jet nozzle provided in the water supply piping seen from the III direction in FIG. The aquaculture apparatus of the present invention in which water supply pipes are concentrically arranged in a circular aquaculture tank. The aquaculture apparatus of the present invention in which the water supply pipe does not have a closed end. The enlarged view of the IV part in FIG. The enlarged view of the water supply piping which the jet nozzle of two adjacent water supply piping does not oppose. The schematic diagram which spouts water from the spout which is narrow inside and is wide outside in a horizontal direction cross section. The schematic diagram which spouts water from the jet nozzle which consists of two or more independent pores. The aquaculture device of the present invention having a swirl flow generator.

  The aquaculture apparatus of the present invention can release contaminants from the entire surface of the sand layer to the water layer to keep the sand layer in a clean state, and can be suitably used for aquaculture of sandy inhabited aquatic organisms that inhabit the sandy land. Examples of the sandy inhabited aquatic organisms that can be cultivated with the aquaculture device of the present invention include shellfish such as prawns, crabs, and clams, shellfish such as clams, swordfish, clams, and fish such as flounder and flatfish. it can.

The schematic diagram of one Embodiment of the culture apparatus of this invention is shown in FIG.
An aquaculture device 100 according to an embodiment has ten water supply pipes 20 arranged at regular intervals at the bottom of the culture tank 10, and each water supply pipe 20 has 11 jets at a constant pitch on the side surface. An outlet 21 is provided. In addition, a drainage device 30 is provided at the center of the culture tank 10.
FIG. 2 shows a schematic diagram of the inside of the aquaculture device 100 as viewed from the II direction in FIG. Moreover, the schematic diagram of the flow of the water from the jet nozzle 21 provided in the water supply piping 20 seen from the III direction in FIG. 1 is shown in FIG.
The aquaculture device 100 ejects water from the jet port 21 on the side surface of the water supply pipe 20 to the side of the water supply pipe 20. The water supply pipe 20 is embedded in the bottom of the sand layer 11, and the water ejected laterally from the jet port 21 gradually diffuses while proceeding through the sand layer 11. The water spouted from the spout 21 is blocked by the bottom surface of the aquaculture tank 10 and cannot travel downward, so that it changes to an upward water flow (hereinafter referred to as an upward water flow) as a whole, and the sand layer 11 is moved upward from below. To penetrate. As the upward water flow permeates through the sand layer 11, the degree of filling of the sand particles forming the sand layer 11 is relaxed, and contaminants such as residual food, feces and molting shells captured by the sand layer 11 are removed from the water layer above the sand layer 11. 12 can be released.

The thickness of the sand layer 11 above the water supply pipe 20 is appropriately selected depending on the type of sandland inhabiting aquatic organisms to be cultivated, but when cultivating prawns, a range of 10 to 40 cm is preferable. If the sand layer 11 above the water supply pipe is thinner than 10 cm, when the water supply pipe 20 is arranged at the bottom of the sand layer 11, the thickness becomes insufficient as a sand floor into which prawns sink, and the sand flows due to upward water flow or water flow in the aquaculture tank. Is likely to cause uneven thickness. If the sand layer 11 above the water supply pipe is thicker than 40 cm, the sand layer 11 that traps contaminants becomes thick, and the effect of releasing contaminants from the sand layer 11 is weakened. Further, the water permeability resistance of the sand layer 11 increases, and a powerful pump for supplying water at a high pressure to the water supply pipe 20 is required to generate an upward water flow, resulting in a high cost.
The sand which comprises the sand layer 11 can be selected according to the kind of sandland inhabited aquatic organism to culture. For example, when cultivating prawns, river sand, sea sand, etc. can be used, and sand containing 20 to 50% of sand having a median particle size of 0.5 to 1.5 mm and 0.2 mm or less is used. preferable.
What is necessary is just to set the depth (water depth) of the water layer 12 suitably according to the kind of sandland inhabited aquatic organism to cultivate, required water quantity, etc.

  The aquaculture tank 10 can be a water tank formed of concrete, fiber reinforced plastic (FRP), a resin sheet or the like, or an aquaculture pond built on the coast. A water tank made of concrete is preferable because it is hard to leak water and has high strength and can accommodate a large amount of sand and water. The aquaculture tank 10 is preferably shielded from the external environment in order to prevent the entry of harmful viruses and pests from the outside. Examples of the shape of the aquaculture tank 10 include polygons such as quadrilaterals, hexagons, and octagons, shapes in which the corners of these polygons are curved, circles, ellipses, and the like.

The water supply pipes 20 are arranged at a constant interval on the bottom of the culture tank 10 so as to be distributed substantially uniformly over the entire bottom surface of the culture tank 10. The water supply pipe 20 is preferably made of resin because it does not rust. In addition, any of a rigid material that cannot be bent and a flexible material that can be bent can be used, but a rigid material that is not crushed by the weight of the sand layer 11 is preferable even when no water pressure is applied to the inside. For example, the water supply pipe 20 can be arranged in a concentric square shape, a concentric circle shape, or the like. Further, one water supply pipe 20 can be arranged in a sine wave shape, a rectangular wave shape, a spiral shape, or the like. As an example, FIG. 4 shows an aquaculture apparatus 101 in which water supply pipes 20 are arranged concentrically in a circular aquaculture tank 10. In FIG. 4, the same members as those in FIG. It is preferable to arrange | position in the range of 5 cm or more and 100 cm or less, and, as for the space | interval of the adjacent water supply piping 20, it is more preferable that it is 10 cm or more and 50 cm or less. If the interval between the adjacent water supply pipes 20 is smaller than 5 cm, the number of water supply pipes 20 increases, the installation work becomes complicated, and the area where car prawns and the like can sink is reduced. When the interval between the adjacent water supply pipes 20 is larger than 100 cm, the water ejected from the jet outlet 21 is difficult to reach the vicinity of the adjacent water supply pipe 20.
FIG. 5 shows an aquaculture device 102 in which the end portions of the respective water supply pipes 20 are connected by communication pipes 22. In FIG. 5, the same members as those in FIG. When the water supply pipe 20 does not have a closed end and the end is connected by the communication pipe 22, the pressure loss in the water supply pipe 20 is reduced, and water is ejected more uniformly from each outlet 21 of the water supply pipe 20. can do.

An enlarged view of the IV portion in FIG. 1 is shown in FIG.
The water supply pipe 20 is provided with jet nozzles 21 at a constant pitch (b) on the side surface. The pitch (b) of the jet ports 21 is preferably smaller than the interval (a) between the water supply pipes 20. By making the pitch (b) of the jet nozzles 21 smaller than the interval (a) of the water supply pipe 20, water can be supplied uniformly over a wide area of the sand layer 11.
Here, in the water supply pipe 20 shown in FIG. 6, the jet outlets 21a and 21b of two adjacent water supply pipes 20a and 20b are opposed to each other. At this time, if the momentum of the water ejected from the respective ejection ports 21a and 21b is too strong, a collision occurs in the vicinity of the middle between the two water supply pipes 20a and 20b. Since the collided water flows strongly upward, the upward water flow at the collision point becomes stronger than the upward water flow at other points, and the sand above the collision point flows, causing unevenness in the thickness of the sand layer 11, and carr shrimp and the like There are cases where the area that can be dive is reduced.

In FIG. 7, the enlarged view of the water supply piping 20 which the jet nozzles 21c and 21d of two adjacent water supply piping 20c and 20d do not oppose is shown. The fact that the spout 21c of the water supply pipe 20c and the spout 21d of the adjacent water supply pipe 20d do not face each other means that the normal line of the water supply pipe wall passing through the center of the spout 21c of the water supply pipe 20c and the adjacent water supply pipe 20d This means that the distance (b ′) from the normal line of the water supply piping wall passing through the center of the jet outlet 21d is 0.2 times or more the pitch (b) of the jet outlets 21c and 21d. The distance (b ') between the normal line of the water supply pipe wall passing through the center of the jet outlet 21c of the water supply pipe 20c and the normal line of the water supply pipe wall passing through the center of the jet outlet 21d of the adjacent water supply pipe 20d is the jet outlet 21c. More preferably, it is 0.3 times or more of the pitch (b) of 21d, more preferably 0.4 times or more, and most preferably 0.5 times.
The distance (b ′) between the normal line of the water supply pipe wall passing through the center of the jet outlet 21c of the water supply pipe 20c and the normal line of the water supply pipe wall passing through the center of the jet outlet 21d of the adjacent water supply pipe 20d is the jet outlet 21c. When the water is ejected from the respective outlets 21c, 21d to the vicinity of the adjacent water supply pipes 20c, 21d at 0.5 times the pitch (b) of 21d, the momentum of the upward water flow in each part of the sand layer 11 Since the thickness becomes uniform, the sand layer is less likely to have uneven thickness.

  The opening shape of the spout 21 is not particularly limited, and examples thereof include a circle, an ellipse, an oval, and a quadrangle. The maximum diameter of the jet nozzle 21 is preferably 0.5 mm or more and 5 mm or less, and more preferably 1 mm or more and 3 mm or less. When the maximum diameter of the jet nozzle 21 is smaller than 0.5 mm, it is likely to be clogged with foreign matters. In addition, when the required amount of water is ejected, the flow velocity becomes too fast, the sand near the spout 21 flows, the thickness of the sand layer 11 becomes uneven, and the sandbed area that can be submerged, such as prawns, is reduced. There is. Moreover, if a strong water flow flows in the sand layer 11, it will give stress to the prawns and the like. When the maximum diameter of the jet nozzle 21 is larger than 5 mm, when a required amount of water is jetted, the water flow becomes weak and it may be difficult for water to reach a region away from the jet nozzle 21.

Water is ejected to the side of the water supply pipe 20 from a jet port 21 provided on the side of the water supply pipe 20. In the present invention, the side means a direction within 30 degrees vertically with respect to the horizontal direction, that is, a direction within 60 degrees with respect to the horizontal direction. By ejecting water in a direction within 30 degrees up and down centering on the horizontal direction, the water can reach further in the horizontal direction.
The water ejected upward widens the gap between the sand particles, expands the sand layer 11, and gradually diffuses while proceeding through the sand layer 11. On the other hand, the water jetted downward collides with the bottom surface of the aquaculture tank 10 to form a vortex, and the sand around the collision location flows, and also collides and loses the flow velocity and does not reach far. Therefore, it is more preferable that the water ejection direction is upward from the horizontal direction than downward from the horizontal direction. Specifically, it is preferably a range from 30 degrees upward to 20 degrees downward, more preferably from 20 degrees upward to 10 degrees downward, and from 15 degrees upward to 5 degrees downward. The range is further preferable, the range from 10 degrees upward to the horizontal direction is particularly preferable, and the jetting in the horizontal direction is most preferable.

  Water can be supplied to the wide area of the sand layer 11 when the spout 21 spouts water in a direction of 15 degrees or more to the left and right around the normal line of the water supply pipe 20 in a horizontal plane, that is, a wide angle of 30 degrees or more. As a method of ejecting water in the direction of 15 degrees or more to the left and right around the normal line of the water supply pipe 20 in the horizontal plane, water is formed in a fan shape so that the outlet 21 is narrow inside the water supply pipe 20 and wide outside. (FIG. 8), a method of forming the ejection port 21 with a plurality of independent pores 211 and ejecting water from each pore 211 in different directions (FIG. 9) can be mentioned. From the viewpoint of workability, strength of the water supply pipe 20, and the like, the angle at which ejection is possible is up to about 60 degrees left and right with the normal line of the water supply pipe 20 as the center. Here, when the ejection port 21 is formed of a plurality of independent pores 211, the center of the ejection port 21 means the center of the position of the plurality of pores 211.

  The flow rate of water when ejected from the ejection port 21 is preferably 2.5 cm / second or more and 100 cm / second or less, more preferably 5 cm / second or more and 70 cm / second or less, and more preferably 10 cm / second or more and 50 cm / second or less. More preferably. If the flow velocity is slower than 2.5 cm / second, the water ejected from the ejection port 21 does not reach far. When the flow velocity is faster than 100 cm / sec, sand near the jet port 21 is caused to flow, and the sand layer 11 may be less than the thickness required for car prawns or the like to sink. In addition, the strong water flow gives stress to car prawns.

  The aquaculture device 100 generates an upward water flow that penetrates the entire surface of the sand layer 11 from the bottom to the top. The upward water flow loosens the degree of filling of the sand particles forming the sand layer 11, and discharges contaminants such as residual food, feces and molting shells trapped in the sand layer 11 to the water layer 12 above the sand layer 11. Contaminants released to the water layer 12 are discharged out of the system by the drainage device 30. A plurality of drainage devices 30 may be installed. Further, the drainage device 30 is provided with a filter 31 for preventing the outflow of car prawns and the like. By providing the drainage device 30 at the center of the culture tank 10, the distance from each part of the culture tank 10 to the drainage device can be shortened, and the contaminants released from the entire surface of the sand layer 11 to the water layer 12 can be efficiently used. Can be discharged.

  Examples of the drainage device 30 include a drainage pump, a cylindrical drainage device that drains water of a predetermined level or higher, and a drainage groove. Moreover, you may drain intermittently using a valve, a water level sensor, etc. 1 and 2 has a cylindrical drainage device as a drainage device 30 at the center of the culture tank 10. The cylindrical drainage device includes a pipe 32 that is connected to a drainage port to prevent sand from flowing out, and a cylindrical filter 31 that surrounds the pipe 32 and prevents outflow of prawns and the like. In the cylindrical drainage device shown in FIGS. 1 and 2, the water level is adjusted by the height of the external outlet 33, but the water level can also be adjusted by draining from the upper opening end of the pipe 32 by overflow. Further, the upper surface and the upper side surface of the filter 31 are set as a region having no opening, and the height of the upper opening end of the pipe 32 is set to be higher than the region not having the opening of the filter 31, and the water is drained by the principle of siphon. You can also. Since the adjustment of the water level is easy, it is preferable to adjust the water level with the height of the external outlet 33. The cylindrical drainage device can be installed at an arbitrary location, does not require a drive source, is low-cost, and can adjust the water level depending on the height of the external outlet 33 and the pipe 32.

  By installing the swirl flow generating device 40 around the inner wall of the culture tank 10, a swirl flow can be generated in the water layer 12. Examples of the swirl flow generating device 40 that generates a swirl flow in the water layer 12 include a circulation pump and a water turbine type recirculation device. It is preferable to use a circulation pump as the swirling flow generator 40 because it is easy to adjust the flow velocity of the swirling flow and oxygen can be supplied into the water. At this time, it is preferable that the aquaculture tank 10 does not have corners so that the swirl flows smoothly, and a shape obtained by processing circular, elliptical, or polygonal corners into a curved surface is preferable. Moreover, when the aquaculture tank 10 has a shape obtained by processing polygonal corners into a curved surface, the water outlet of the swirling flow generating device 40 has a length equal to or less than a half of the side length and is adjacent to the water discharge port. If two or more are installed at regular intervals on one side of the wall surface to be rotated, a swirling flow can be efficiently generated. In FIG. 10, a circulation pump having a water discharge port that is less than or equal to one half of the length of the side as a swirling flow generator 40 is adjacent to two opposing sides of the square-shaped aquaculture tank 10 whose corners are curved. The aquaculture apparatus 103 installed in the one side of the wall surface to perform is shown. In FIG. 10, the same members as those in FIG.

The flow velocity of the swirling flow in the depth direction is faster in the shallow part and becomes slower as it gets deeper, that is, as it approaches the sand layer 11. The speed of the swirl flow is preferably such that the sand particles on the surface of the sand layer 11 are gently agitated. When cultivating crustaceans such as prawns, the flow speed of the swirl flow on the surface of the water layer 12 is 5 to 30 cm, depending on the depth of the water. Per second.
The swirling flow having an appropriate flow velocity gently agitates the surface of the sand layer 11 and releases the contaminants carried to the surface of the sand layer 11 by the upward water flow and the contaminants buried in the sand layer 11 to the water layer 12. Make it easier. Moreover, moderate agitation of the surface of the sand layer 11 acts in the same manner as agitation of sand by wave and tide fullness, bringing the habitat such as prawns closer to the natural environment and reducing stress such as prawns. On the other hand, when the flow velocity of the swirl flow is too high, sand particles on the surface of the sand layer 11 are rolled up, and the sand layer 11 may be uneven in thickness, thereby narrowing a region where the shrimp or the like to be cultured can be submerged. Also, if the flow rate is too fast, it will stress the shrimp and the like.
Due to the swirling flow, contaminants floating in the water can be collected in the central portion of the culture tank 10. At this time, if the water is drained from the center of the culture tank 10, the contaminants collected in the center of the culture tank 10 can be discharged more efficiently. In addition, what is necessary is just to scrape and discard the large contaminants, such as the molting shell which cannot pass the filter 31 of the drainage device 30, with the net | network etc. near the filter 31 vicinity. If the flow velocity of the swirl flow is too high, the contaminants released and floating in the water layer 12 are diffused over the whole without being focused on the center of the aquaculture tank 10, and as described above, the sand layer The degree to which 11 sand particles are gently stirred is preferred.

Water supply from the water supply pipe 20 is generally in the range of 1 day sand 1 m ² in ^{0.5~5m 3 (0.5m 3 / 1m 2} · day or more ^{5 m} 3/1 m or less ² · day). Ability to release sand contaminants in 11 water layer 12, so determined by the speed and extent how upward water flow, the water supply amount is less than 0.5m 3 / ^1m 2 ^· day, cleaning effect of the sand layer 11 Becomes weaker. When the water supply amount is 5m 3 ^/ 1m more than 2 ^per day, the sand layer 11 becomes unstable to flow, stress the sandy habitat aquatic organisms of aquaculture subject.

  The total amount of fresh water required for aquaculture is determined by the amount of water stored in the aquaculture tank 10 and the water exchange rate. When the total amount of fresh water supplied is greater than the amount of water supplied from the water supply pipe 20, fresh water is supplied from the water supply pipe 20, and surplus fresh water is supplied directly to the aquaculture tank 10 or the swirling flow generator 40. When the total amount of fresh water supplied is less than the amount of water supplied from the water supply pipe 20, the water in the culture tank 10 is added to the fresh water and supplied from the water supply pipe 20.

Next, although this invention is demonstrated based on an Example, this invention is not limited only to these.
"Aquaculture equipment"
A concrete square water tank with a length of 8 m, a width of 8 m, and a height of 1.2 m was used as a culture tank. The aquaculture tank has a drain port having a diameter of 100 mm and a pipe mounting groove having a diameter of 200 mm surrounding the drain port concentrically at the center. A resin pipe having a diameter of 200 mm was fitted into the pipe mounting groove so that the upper surface of the resin pipe was 20 cm high from the bottom of the culture tank. As a filter for preventing the outflow of prawns, a cylindrical resin net having a mesh of 3 mm in length and 3 mm in width was attached to the outer periphery of the resin pipe so as to have a height of 120 cm. At the outlet of the drain outlet, a resin pipe with a diameter of 100 mm is 1 m from the bottom of the culture tank so that when the water in the culture tank reaches a certain height (1 m), it automatically drains to the outside of the culture tank. It was installed to become.
As a water supply main pipe, a resin pipe having a diameter of 50 mm was installed from the upper side to the lower side at the center of one wall surface of the culture tank, and branched by 4 m left and right along the culture tank wall surface at the bottom of the culture tank. A total of 40 connecting holes for connecting the water supply pipes are formed at intervals of 20 cm in the water supply main branched from the bottom of the aquaculture tank. An 8m long water supply pipe consisting of a resin hose with 1.0mm diameter jets formed at 20cm pitch on both sides is connected to this connection hole. Installed in. The spout of the water supply pipe is in the range from 10 degrees upward to the horizontal direction, and the spouts of the two adjacent water supply pipes face each other.

River sand was spread at a height of 15 cm to form a sand layer. The resin pipe fitted into the discharge port protrudes by 5 cm from the surface of the sand layer, and can prevent the sand from flowing out from the drain port. As described above, water accumulates up to 1 m from the bottom of the culture tank, so the water depth is 85 cm (= 100 cm-15 cm). When filtered seawater is sent to this water supply main, it can be confirmed that the water rises from the entire surface of the sand layer, and the water spouted from the spout provided in each water supply pipe forms an upward water flow over the entire surface of the sand layer. It was.
One 0.25 kw submersible pump as a circulation pump was hung on the wall surface of the aquaculture tank at a height of 30 cm from the sand layer, and the drain outlet was installed in parallel with the water surface. In addition, a resin net and an oxygen supply tube for preventing the inhalation of prawns were attached to the water inlet of the circulation pump. When the circulation pump was operated, the water in the culture tank swirled at a flow velocity of 20 cm / second on the surface of the water layer.

"Example 1"
The total amount of water supplied to the aquaculture tank was set to 2 rotations / day, and the total amount of water supplied was continuously supplied from the water supply pipe. The amount of water supplied from the water supply pipe can be calculated to be 1.7 m ³ / m ² · day, and the jetting speed of water from the jet outlet can be calculated as 50 cm / sec.
The amount of dissolved oxygen in water was maintained at 7 ± 1 mg / L, and 3200 prawns with a body weight of around 5.6 g were housed to start breeding.
As the feed, Higashimaru Co., Ltd., a prawn mixed feed was used, and was administered once a day after sunset. The daily feeding amount was calculated based on the feeding rate recommended by the feed manufacturer, and the appropriate amount was calculated from the number of accommodated cattle and body weight. Also, large contaminants such as the molting shell that cannot pass through the mesh of the resin net were removed as appropriate.
During the breeding period, we observed drowning, molting, and residual food by diving every day. Further, twice daily in the morning and evening, the temperature of the breeding water, the amount of dissolved oxygen, and pH were measured with a portable dissolved oxygen / pH meter (manufactured by Toa DKK Corporation, device name: DM-32P).
14 weeks after the start of the breeding, all the prawns were picked up and the breeding was terminated.

“Comparative Example 1”
The prawns were reared under the same conditions as in Example 1 except that the flow-through method (conversion rate was 0.5 times / day), which is a conventional aquaculture method.
Hereinafter, Example 1 bred with the culture device of the present invention is referred to as a test group, and Comparative Example 1 bred with a conventional pouring type is referred to as a control group.

"Sulphide concentration measurement"
Every 4 weeks, the concentration of sulfide in the sand at the center of the aquaculture tank and the wall around 1 m from the outer wall of the aquaculture tank was measured using a gas concentration meter (Gastec Co., Ltd., Hedrotech-S detector tube, gas Measurement was performed using a collector Model 801).
“Shrimp Calibration”
Every two weeks, 100 pigs were randomly picked from domestic prawns, weighed, and the average body weight was calculated by dividing the weight by the number of fish.

“Measurement results of sulfide concentration”
Table 1 shows the sulfide concentration during the test period.

In the test area, no sulfide was detected until the 4th week, and the highest 21.2 mg / g was detected at the 12th week. Further, in the peripheral part of the wall of the culture tank, sulfide was not detected until the 8th week, and it was a trace amount of 0.2 mg / g even at the 12th week.
In contrast, in the control plot, the sand in the center of the aquaculture tank detected 22.2 mg / g of sulfide at the 4th week, which was almost the same as the 12th week in the test plot, and continued to rise for 12 weeks. Later, it was 50.8 mg / g. In addition, 1.4 mg / g of sulfide was detected in the periphery of the aquaculture tank wall at the 4th week, and the sulfide concentration in the sand increased as the breeding progressed thereafter. After 12 weeks, 10.0 mg / g g.
Sulfide was detected at a higher concentration in the center than in the periphery of the aquaculture tank wall in both the test and control areas. This is because contaminants accumulate in the center of the culture tank due to the swirling flow generated by the circulation pump.
In the test area, even after 12 weeks of cultivation, there is almost no accumulation of sulfides except around the drainage port. Less sulfide means less other pollutants, so the contaminants to be removed in the cleaning operation after the cultivation is concentrated around the drain. Therefore, the aquaculture apparatus of the present invention only needs to clean the sand layer and the like after completion of the aquaculture only around the drain outlet, and the cleaning operation can be greatly simplified and further omitted.

"Growing state of prawns"
Table 2 shows the transition of the average body weight, and Table 3 shows the transition of the increased amount of meat. The increased amount of weight is the difference in average body weight before and after the passage of two weeks, that is, the amount of weight gain during two weeks.

  From Table 2, the average weight of the shrimp in the test group exceeded the average weight of the control shrimp throughout the breeding period. Moreover, from Table 3, it was confirmed that the shrimp in the test group showed a higher thickness than the control group in any period, and the growth was fast.

試験区の歩留まりは９２％と、対照区の８６％を大きく超えていた。対照区の歩留まりも８６％と一般的な従来のクルマエビ養殖の歩留まり（６０−７０％）より高いが、これは、約５．６ｇにまで成長した稚エビで養殖を開始したためである。本発明の養殖装置を、実際の養殖条件、養殖期間で用いれば、従来方法よりも１０％以上歩留まりが向上すると推測される。 Table 4 summarizes the results of the breeding test. The feed rate and the number of meat increase are calculated using the following formula from the amount of feed (F) given during the breeding period, the number of breeding days (D = 95 days), the number of accommodated fish at the start and end of the test, and the average weight. It is represented by
Feeding rate = F / [D × {(N _f + N ₀ ) / 2} × {(W _f + W ₀ ) / 2}] × 100
Thickening factor = F / [{(N _f + N ₀ ) / 2} × (W _f −W ₀ )]

The yield of the test plot was 92%, greatly exceeding 86% of the control plot. The yield of the control zone is 86%, which is higher than the conventional conventional shrimp farming yield (60-70%), because the farming started with juvenile shrimp that grew to about 5.6 g. If the aquaculture apparatus of the present invention is used under actual aquaculture conditions and aquaculture period, it is estimated that the yield is improved by 10% or more than the conventional method.

  The feeding rate of the prawns in the test group was 1.8%, which was lower than the feeding rate of 2.0% in the control group. A low feeding rate means that higher meat gain was obtained with less feed. This is consistent with the fact that the growth coefficient of the shrimp in the test group is superior to that of the control shrimp. That is, it was confirmed that the test plot was an environment suitable for growth for the prawns compared to the control plot.

The production volume at a typical prawn aquaculture site is around 500 g per 1 m ² , but in the test area of this example, the accommodation density at the end of the breeding is 1292 g / m ^2, which is about 2. I was able to raise six times as many prawns. Even in the control group, the housing density was as high as 1072 g / m ² , because the cultivation was started with juvenile shrimp that had grown to about 5.6 g as described above.
As described above, in the test area using the culture apparatus of the present invention, since the sand layer is kept clean, the sand layer cleaning operation can be significantly simplified and further omitted after the shipment is completed. If cleaning of the sand layer is unnecessary, the next juvenile shrimp can be accommodated immediately after the cultivation. If the aquaculture period is 6 months, production can be performed twice a year by starting the next aquaculture immediately after the end of the aquaculture. Since the aquaculture apparatus of the present invention can accommodate prawns at a density of 1292 g / m ² , it can be expected to produce about 2.6 kg / 1 m ² · years, which is more than five times more productive than the conventional one. have.

"Shark prawns"
The length of the shrimp beard (second tactile sensation) cultivated in the test plot and the control plot was investigated. About 80% of the individuals had beards longer than the full length in the test group and about 40% in the control group. Individuals whose beard length was shorter than the head and chest were not found in the test group, and about 30% in the control group.
In general, when prawns are cultured at high density, beards become shorter. This is because when prawns are raised at high density, they receive density stress and attack each other. The test plot had more long-skinned prawns than the control plot, and despite the use of the same sized aquaculture tank, the test plot had a lower shrimp breeding density than the control plot. The reason for the difference in breeding density between the test plot and the control plot is estimated as follows.
In the test area, the occurrence of sulfide in the sand was suppressed over the entire sand layer, and it was considered that the shrimp lived dispersed over the entire sand layer, and the shrimp could be reared at a rearing density calculated from the area of the aquaculture tank.
In contrast, the control group has a region with a high sulfide concentration. Sand with accumulated sulfides is in an anaerobic environment and has a low oxygen concentration and is not suitable as a living area. The prawns do not submerge in areas where the sulfide concentration is high, but concentrate in areas where the sulfide concentration is low, so the actual breeding density was higher than the breeding density calculated from the area of the aquaculture tank.

  When prawns are cultured with the aquaculture apparatus of the present invention, a fast growth rate is achieved with a low feeding rate, and prawns can be produced with a significantly high yield and aquaculture density. Moreover, the period between aquaculture and the following aquaculture can be shortened, and the operation rate of a culture apparatus can be made high. Further, the shape of the prawn is also subject to evaluation, and the longer the beard is traded at a higher price, the cultured apparatus of the present invention makes it possible to produce the prawn that has a long beard and is traded at a high price in the market.

DESCRIPTION OF SYMBOLS 100 Aquaculture apparatus 10 Aquaculture tank 11 Sand layer 12 Water layer 20 Water supply piping 20a-20d Water supply piping 21 Spout 21a-21d Spout 211 Pore 22 Communication pipe 30 Drainage device 31 Filter 32 Pipe 33 External outlet 40 Swirling flow generator

101-103 aquaculture equipment

In FIG. 7, the enlarged view of the water supply piping 20 which the jet nozzles 21c and 21d of two adjacent water supply piping 20c and 20d do not oppose is shown. The fact that the spout 21c of the water supply pipe 20c and the spout 21d of the adjacent water supply pipe 20d do not face each other means that the normal line of the water supply pipe wall passing through the center of the spout 21c of the water supply pipe 20c and the adjacent water supply pipe 20d This means that the distance (b ′) from the normal line of the water supply piping wall passing through the center of the jet outlet 21d is 0.2 times or more the pitch (b) of the jet outlets 21c and 21d. The distance (b ') between the normal line of the water supply pipe wall passing through the center of the jet outlet 21c of the water supply pipe 20c and the normal line of the water supply pipe wall passing through the center of the jet outlet 21d of the adjacent water supply pipe 20d is the jet outlet 21c. More preferably, it is 0.3 times or more of the pitch (b) of 21d, more preferably 0.4 times or more, and most preferably 0.5 times.
The distance (b ′) between the normal line of the water supply pipe wall passing through the center of the jet outlet 21c of the water supply pipe 20c and the normal line of the water supply pipe wall passing through the center of the jet outlet 21d of the adjacent water supply pipe 20d is the jet outlet 21c. , at 0.5 times the 21d pitch (b), each of the ejection ports 21c, the jetting water to the vicinity of the feed water pipe 20c, 2 0 d adjacent the 21d, upward water flow in each portion of the sand layer 11 Since the momentum is uniform, it is difficult for the sand layer to have thickness unevenness.

試験区の歩留まりは９２％と、対照区の８６％を大きく超えていた。対照区の歩留まりも８６％と一般的な従来のクルマエビ養殖の歩留まり（６０−７０％）より高いが、これは、約５．６ｇにまで成長した稚エビで養殖を開始したためである。本発明の養殖装置を、実際の養殖条件、養殖期間で用いれば、従来方法よりも１０％以上歩留まりが向上すると推測される。 Table 4 summarizes the results of the breeding test. Incidentally, feeding rate and the thickening coefficient is the amount of the feed given during the feeding period (F), and a breeding days (D = 95 days), and at the beginning of the test and at the end of the housing tail number and the average weight, the following It is expressed by a formula.
Feeding rate = F / [D × {(N _f + N ₀ ) / 2} × {(W _f + W ₀ ) / 2}] × 100
Thickening factor = F / [{(N _f + N ₀ ) / 2} × (W _f −W ₀ )]

The yield of the test plot was 92%, greatly exceeding 86% of the control plot. The yield of the control zone is 86%, which is higher than the conventional conventional shrimp farming yield (60-70%), because the farming started with juvenile shrimp that grew to about 5.6 g. If the aquaculture apparatus of the present invention is used under actual aquaculture conditions and aquaculture period, it is estimated that the yield is improved by 10% or more than the conventional method.

"Shark prawns"
To investigate the length of the beard of farmed prawns (second touch corner) in the control group and the test group. About 80% of the individuals had beards longer than the full length in the test group and about 40% in the control group. Individuals whose beard length was shorter than the head and chest were not found in the test group, and about 30% in the control group.
In general, when prawns are cultured at high density, beards become shorter. This is because when prawns are raised at high density, they receive density stress and attack each other. The test plot had more long-skinned prawns than the control plot, and despite the use of the same sized aquaculture tank, the test plot had a lower shrimp breeding density than the control plot. The reason for the difference in breeding density between the test plot and the control plot is estimated as follows.
In the test area, the occurrence of sulfide in the sand was suppressed over the entire sand layer, and it was considered that the shrimp lived dispersed over the entire sand layer, and the shrimp could be reared at a rearing density calculated from the area of the aquaculture tank.
In contrast, the control group has a region with a high sulfide concentration. Sand with accumulated sulfides is in an anaerobic environment and has a low oxygen concentration and is not suitable as a living area. The prawns do not submerge in areas where the sulfide concentration is high, but concentrate in areas where the sulfide concentration is low, so the actual breeding density was higher than the breeding density calculated from the area of the aquaculture tank.

Claims (7)

An aquaculture tank,
Water supply pipes arranged at regular intervals at the bottom of the aquaculture tank;
Have
The aquaculture apparatus for sandy inhabited aquatic organisms, wherein the water supply pipe is provided with spouts on a side surface at a constant pitch.   The aquaculture apparatus according to claim 1, wherein a pitch of the jet holes is smaller than an interval between the water supply pipes.   The aquaculture apparatus according to claim 1, wherein the water supply pipe does not have a closed end.   The aquaculture apparatus according to any one of claims 1 to 3, wherein a jet outlet of the water supply pipe does not face a jet outlet of an adjacent water supply pipe.   The aquaculture apparatus according to any one of claims 1 to 4, wherein the spout spouts water in a direction of 15 degrees or more to the left and right around a normal line passing through the spout center.   The aquaculture apparatus according to any one of claims 1 to 5, wherein water is drained from a central portion of the aquaculture tank.   The aquaculture apparatus according to any one of claims 1 to 6, further comprising a swirl flow generator installed around an inner wall of the aquaculture tank.

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