JPH10117630A - Aquatic animal and plant breeding method and water tank for breeding aquatic animal and plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manage the breeding of the seed/seedling of flatfish by preventing the abnormality of a body color which turns a part of the whole of its no eye side black at the time of breeding. SOLUTION: Sand 24 is laid on the bottom 7 of a water tank 1 and a channel 5 is formed annularly to make a circulating type. As seawater is supplied din one direction of a circulating channel to circulate seawater, the feces and the residual feed of a flat fish A accumulated on the sand 24 are discharged from a discharging port 14 with the sand 24 by a stream X. As the growing environment of the flatfish A is created with the sand 24 and the faces and the residual feed are discharged by the stream X in addition, it is necessitated to manually clean the water tank 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to flounder, flounder,
The present invention relates to a method of cultivating aquatic animals and plants for aquatic animals such as shrimp, sea cucumber, shellfish, and aquatic plants such as seaweed, and an aquarium for culturing aquatic animals and plants.

[0002]

Conventionally, flounder has been cultured as a kind of aquatic animal. Flounder is distributed all over Japan and in Sakhalin, Korea, and China. The eyes are close to the left, and the eyes are blackish brown with white, the eyes are white, and the sand is white. The bottom is a growth environment and it works for bait at night, and it is very delicious as sashimi and boiled. The eyes of the flounder fry are initially located on the left and right sides of the head like ordinary fish, but are 8m long
Metamorphosis starts around m, the body shape gradually shifts to the side, and the eyeball on the body side, which will become the eyeless side in the future, starts moving upward. Then, the transformation is completed when the body length is around 16 mm, and the so-called flatfish shape is obtained.

In flounder culture, after hatching in a small or large aquarium such as a box, the flounder is raised in zooplankton rotifers or hatchling larvae, and the proportion of feed fed gradually is increased after the metamorphosis. After growing, for example, the total length is 2-3
cm, the seedlings in the small aquarium move to the large aquarium, and the seedlings in the large aquarium are repeatedly grown in the large aquarium while feeding the compound feed, and then intermediately grown. Released or raised to edible size.

Conventional large-sized aquariums for intermediate breeding are made of, for example, FRP, concrete, or the like, and have a circular or square flat surface. Seawater is continuously supplied for aquaculture. Flounder grown in such an aquarium has a problem in that so-called body color abnormality occurs in which part or the whole of the eyeless side of the flatfish that originally becomes white becomes black. Even when such flounder with abnormal body color is landed, its commercial value is low.

[0005] To elucidate this cause, in recent studies, at the experimental level, sandpaper or sand was laid on the bottom of the water tank, and the difference in the bottom quality of the water tank, particularly friction and abnormal eyeless body color, were examined. It was known that the colorlessness of the flounder on the iris side of the flounder was reduced in the experimental plots covered with.

[0006] However, as described above, in aquaculture in which flounder is grown by laying sand in an aquarium, excreta and secretions of the flounder or remaining bait accumulate not only in the sand, but also in the sand. As a result, the water quality deteriorates, which causes not only the occurrence of fish disease, but also the generation of hydrogen sulfide and the like, which results in an environment where flounder cannot grow. Therefore,
It is necessary to periodically clean the bottom of the aquarium to remove dirty sand and replace it with new sand again. However, sand containing a large amount of putrefactive substances is extremely difficult to handle because hydrogen sulfide can be generated. For example, when removing dirty sand,
If sand is soaked in water, the quality of the water deteriorates at once, and it is very dangerous for aquatic organisms. In addition, if flounder is buried in the sand where hydrogen sulfide is generated, it is immediately killed by hydrogen sulfide. Sand is heavy and cannot be easily removed. Flounder is an organism that lives on and in the sand, so sand removal is nearly impossible. Therefore, it was not possible to cultivate with litter by ordinary breeding methods. In addition, in conventional culture without litter, the excreta and secretions of flounder or residual food accumulate not only on the bottom of the aquarium, but also on the bottom of the aquarium. To remove the deposits. Cleaning the bottom of such an aquarium requires a great deal of labor and experience, and the cleaning of the bottom causes the flatfish seedlings to be traversed and hurt.
In recent years, circulating water tanks that do not accumulate excreta, secretions, or residual food on the bottom of the water tank have been put into practical use. However, even if these water tanks are used, the body color abnormality of the flatfish eyeless side occurs. There was a problem.

[0007] Even when aquatic animals such as flatfish, crab, shrimp, sea cucumber, shellfish and aquatic plants such as seaweed are cultured in the aquarium, cleaning the bottom of the aquarium requires a great deal of labor and experience.
Furthermore, there is a possibility that aquatic animals and plants may be damaged by the bottom cleaning.

Therefore, the present invention solves the above problems and provides a method for cultivating aquatic animals and plants that can maintain an aquarium for cultivating aquatic animals and plants in a sanitary manner without requiring much labor and that can satisfactorily cultivate without damaging aquatic animals and plants. The purpose is to provide. Another object of the present invention is to provide a method for cultivating aquatic animals and plants, which can satisfactorily cultivate aquatic animals and plants that use sand such as flounder as a growth environment. Still another object of the present invention is to provide an aquarium for aquatic animals and plants that can satisfactorily culture aquatic animals and plants.

[0009]

According to a first aspect of the present invention, there is provided a method for cultivating aquatic animals and plants by laying sand on the bottom of an aquarium for cultivating aquatic animals and plants. By sequentially discharging the water from the water tank and supplying sand to the bottom of the water tank, the excrement of aquatic animals and plants can be discharged together with the sand.

According to a second aspect of the present invention, the water tank is of a circulation type in which a water channel is formed in an annular shape, and the water is circulated by supplying the water in one direction of the circulation water channel.
And, by the circulating water flow, a part of the sand laid on the bottom together with the water is discharged from a discharge port provided at the bottom of the water tank. Sand is sequentially discharged from the discharge port, and since the discharge port is provided at the bottom of the water tank, the sand naturally falls to the discharge port.

A third aspect of the present invention is to provide a reticulated body having a small hole at an upper part of the outlet and a reticulated body having a large hole at a lower part, and cutting the small-mesh body with the growth of aquatic animals and plants. By expressing a net having a large hole, the resistance of the drain can be reduced with the growth of aquatic animals and plants.

A fourth aspect of the present invention is characterized in that the aquatic animals and plants have sand as a growth environment, and the sands can create an aquatic animal and plant growth environment.

According to a fifth aspect of the present invention, since the sand contains sand having a particle size of 100 micrometers or more, the sand is not soared by the water flow, and the sand is surely removed together with the excrement by the water flow. Can be discharged.

According to a sixth aspect of the present invention, an outer peripheral plate is erected on the outer periphery of the bottom of the water tank, and a partition plate is provided at the center of the bottom to form an annular water passage, and a discharge port is provided at the bottom. A water tank for culturing aquatic animals and plants, wherein a concave arc portion is formed in each of a first connection portion between the bottom and the outer peripheral plate and a second connection portion between the bottom and the partition plate. Aquatic plants and animals can move along the arc.

According to a seventh aspect of the present invention, an air ejection pipe is buried in the second connection portion formed in the concave arc portion, and air ejection holes are provided in the air ejection pipe at intervals. The water tank for culturing aquatic animals and plants according to claim 6, wherein air can be immediately blown out from the air blowing hole even when water supply is stopped due to a failure of a water supply pump or the like.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The flat surface of a water tank 1 made of FRP, concrete or the like for cultivating flounder A, which is installed indoors, has a rectangular intermediate part 2 and semicircular parts 3 on both sides. A partition plate 4 is provided to form an annular water channel 5. Partition plate 4 for aquarium 1
A water pipe 6 is disposed above the water pipe, and seawater sucked from the sea by a pump (not shown) is supplied to a proximal end 6A of the water pipe 6 through a filtering device (not shown). Further, a branch pipe 8 extending to the bottom 7 side of the water tank 1 is connected to the base 6A and the tip 6B of the water pipe 6 and an intermediate portion thereof, and an ejector for entraining air into water is provided above the branch pipe 8. 9 is provided, and a water ejection pipe 10 is connected to the lower part. The water ejection pipe 10 is provided along the bottom 7, and the water ejection hole 11 is directed in one direction of the water channel 5. In addition, it is preferable that the height of the water ejection pipe 10 can be adjusted as needed. Accordingly, seawater sucked from the sea by a pump (not shown) passes through the water pipe 6, the branch pipe 8, and the water ejection pipe 10 and is ejected from the water ejection hole 11 in a state where air is mixed therein, and together with supply of dissolved oxygen, , A one-way water flow X is generated in the water channel 5. Further, an air ejection pipe 12 is provided along the lower portion of the partition plate 4, and a plurality of air ejection ports 13 are formed in the air ejection pipe 12 at intervals. And partition plate 4
Is connected to the air ejection pipe 12.
Therefore, compressed air supplied from an air compressor (not shown) is supplied to the air outlet 13 through the air pipe 13A and the air outlet pipe 12.
Spouts into the water tank 1. Further, seawater outlets 14 are provided at four places on the bottom 7 of the water tank 1. The outlet 14 opens a part of the bottom 7 and a perforated plate 15 is provided at the outlet 14.
The perforated plate 15 has its edge fixed to the edge of the discharge port 14 via a holding plate 15B with a bolt 15A. Further, a mesh body 1 such as a mesh made of a material such as nylon fiber or a metal wire such as stainless steel or a synthetic resin sheet formed with a plurality of small holes formed of a material which can be easily cut with scissors or a cutter knife so as to cover the upper part of the perforated plate 15.
6, 17, and 18 are overlapped. This net 16, 17, 18
Is fixed by sandwiching each edge between the perforated plate 15 and the holding plate 15B.
The first mesh 16 located above has a small hole called an eye, the third mesh 18 located below has a large hole, and the hole of the second mesh 17 in the middle has the first hole. , 3 are formed to have an intermediate size between the meshes 16 and 18. In addition, the first,
The pores of each of a few meshes 16, 17, and 18 are larger than the sands described below, and the pores of the first mesh 16 are smaller than the flounder seedlings at the beginning of growth, and the second mesh is The hole 17 is smaller than the growing flounder seedling, and the hole of the third net 18 is smaller than the growing flounder seedling. Further, a hollow chamber 19 is provided below each of the discharge ports 14, and this hollow chamber 19 is provided.
Connect the discharge pipe 20, which is the discharge path, to the discharge pipe 19.
An opening / closing valve 20A is provided at 20 so that seawater in the water tank 1 can be discharged according to a predetermined opening degree. That is, the first outlet
Seawater, which will be described later, is discharged from the first discharge pipe 20, and seawater discharged from the second discharge port 14 ′ is discharged from the second discharge pipe 20 ′. The seawater drained from the outlets 14 ″, 14 ′ ″ is drained by the third and fourth discharge pipes 20 ″, 20 ″ ″.
In the drawing, reference numeral 21 denotes a bracket for preventing the water pipe 6 and the water tank 1 from spreading due to water pressure, and reference numeral 22 denotes a discharge port of the overflow pipe.

Further, the bottom 7 forming the water tank 1 and the outer peripheral plate 1
A is formed so as to be a concave circular arc portion 1B having a radius R of 50 to 100 mm, preferably 65 to 70 mm. Similarly, a connection portion between the bottom 7 and the partition plate 4 is formed with a radius R of 5 mm.
It is formed so as to be a concave arc portion 4A of 0 to 100 mm, preferably 65 to 70 mm. And this arc part 4
A air ejection pipe 12 is embedded in A and an air ejection port 13 is provided so as to represent the air ejection pipe 13.

When flounder A is cultured using such a water tank 1, first, the water tank 1 is filled with seawater 23, and the bottom 7 is sand 24, and synthetic resin granules formed to the size of sand are used. , Especially sand 24, having a thickness W of, for example, 0.5 to 20 mm, preferably 3 to 10 mm. Further, seawater mixed with air is spouted from the water spouting hole 11 into the seawater 23 in one direction, for example, 2 to 20 cm.
/ Sec, preferably 2-10 cm / sec at the beginning of growth,
Near the end of the growth, the water flow X should be 6 to 15 cm / sec.
To form If there is a possibility that the oxygen in the seawater may become low, air is spouted from the air jet port 13 into the seawater 23 as necessary to supplement it. In this state, the flounder A seeds
When stored inside, flounder A penetrates the layer of sand 24. When the water supply is stopped and a medicine bath or the like is performed, the water is similarly spouted into the seawater 23 to replenish the water. With the flounder A accommodated in this way, the mixed feed is fed, for example, two to three times / day to perform aquaculture. At this time, excrement B and secretion of flounder A are generated, and the excretion B and the remaining food are deposited on the surface of the sand 24 or a part thereof is discharged from the sand 24.
Into the layers of However, seawater 23
Due to the water flow X, the surface layer portion 24A of the sand 24 sequentially flows together with the excrement B and the like toward the outlet 22 side, and flows out to the cavity chamber 19 together with the seawater 23 through the nets 16, 17, 18 and the perforated plate 15. And the cavity room
The seawater 23 and sand 24 in 19 are discharged to the outside, for example, the sea, through the discharge pipe 20. In this way, the water 7 is used to remove the sand 24 at the bottom 7.
Decrease gradually with the excrement B.

When the amount of the sand 24 decreases, new sand is generated.
Supply 24B. The replenishing sand 24B is preferably washed, and is replenished based on, for example, the thickness of the sand 24 on the bottom 7 and the dirt condition, or replenished based on, for example, a time every 12, 24, or 36 hours. But supply sand
The amount of 24B is appropriately changed depending on the size of the water tank 1, the size of the flounder A, the number of the stored fish, and the like. The position where the sand 24B is replenished may be any location other than the outlet 22. In particular, the sand 24 is easily flown by intermittently or continuously replenishing the water in the vicinity of the water ejection hole 11 sequentially. By constantly discharging the excrement B and the like together with the sand 24 in this manner, the layer of the sand 24 can be maintained in a sanitary manner, and a growth environment for flounder A can be secured.

The sand 24 particularly suitable for flounder A has a particle size of 100 micrometers or more, preferably 100 to 2000 micrometers, more preferably 250 to 1000 micrometers. In the experiment, as shown in FIG. 5, the state of the sand where the blackening of the flounder did not progress was as shown in FIG.
0 ~ 500 micrometer medium sandstone and 500 ~
Coarse sandstone of 1000 micrometers occupies nearly 90%, and most of the corners of these sand grains are rounded. The color of the sand was mostly blackish colored rock fragments, most of which were clean sand, and the sand contained shells in addition to quartz caxenite. As for other sand states, as shown in FIG. 6, the particle size composition is such that coarse-grained sandstone having a particle size of 500 to 1000 μm and extremely coarse-grained sandstone having a particle size of 1000 to 2000 μm account for 90% or more. Most of the sand grains had sharp and sharp corners.

At the beginning of growing flounder A seeds,
Sand 24 along with seawater 23 through the first to third nets 16, 17, 18
To discharge. At this time, the flounder A seeds do not escape through the first net 16 having small holes (eyes). When the flounder A grows relatively large, the first net 16 is cut and removed to reveal the second net 17, and the sand 24 together with the seawater 23 is passed through the holes of the first and second nets 17, 18. Discharge. At this time, the seedling of flounder A that became slightly larger
Does not come off due to the mesh member 17 of FIG. Further, when the flounder seedlings became larger, the second net 17 was cut off and removed.
To represent the reticulated body 18. At this time, the seedlings of the flounder A, which have become larger, do not come off due to the third net 18 having a large hole. The drainage efficiency at the drain port 14 is the second,
When the three nets 17 and 18 are provided, the height increases in the order in which only the third net 18 is provided.

When the flounder A moves in the water tank 1 and collides with the connecting portion between the bottom 7 and the outer periphery 1A or the connecting portion between the partition plate 4 and the bottom 7, these will be concave arc portions 1B and 4A, respectively. Therefore, the possibility that the flounder A is damaged can be reduced.

As described above, in the above embodiment, water is supplied to the water tank 1 for cultivating flounder A seeds, and a part of the sand 24 of the bottom 7 is discharged from the water tank 1 by the water flow X. Flounder A while supplying sand 24B to the bottom 7 of 1
, The excrement B and the remaining food are constantly discharged together with the sand 24 by the water flow X, so that the bottom 7 can be kept hygienic at all times, and thus the entire inside of the water tank 1 can be kept hygienic. The growth environment of flounder A can be improved. In addition, the cleaning of the water tank 1 is not performed by cleaning the bottom, but by simply replenishing the sand 24B. Therefore, the management is easy, and there is no need to follow the flounder A like the bottom cleaning. No stress.

The water tank 1 is of a circulation type in which the water channel 5 is formed in an annular shape. By supplying seawater in one direction of the circulation water channel 5 and circulating the seawater, most of the flatfish Since A grows in order to the upstream, it can prevent the phenomenon of cannibalism and stress of flounder A in high density. And circulating water flow X
As a result, part of the sand 24 spread on the bottom 7 together with the seawater is discharged from the discharge port 14 provided on the bottom 7 of the water tank 1, so that the excrement B
In addition to the above, the sand 24 of the surface portion 24A naturally falls to the discharge port 14 by the water flow X and is discharged, so that the sand 24 does not soar and the seawater does not become cloudy.

Further, a net 16 having a small hole (mesh) capable of discharging sand 24, a net 17 having a medium hole, and a net 18 having a large hole are superimposed on the outlet 14 so that the flounder A Since the nets 16, 17, and 18 are cut and removed one after another to improve drainage efficiency with the growth, there is no need for an operator to enter the water tank 1 and replace the nets, thereby simplifying the work of the operator. The flounder A can be grown without giving stress to the flounder A without following the flounder A.

A water tank 1 in which sand 24 is spread on the bottom 7 of the water tank 1
In addition, by cultivating flounder A with sand 24 as a growth environment,
The sand 24 can purify the inside of the aquarium 1 as described above, and can also create a growth environment in which flounder A can be buried.

In addition, by containing sand having a particle size of 100 micrometers or more, preferably 100 micrometers to 2000 micrometers, the seawater 24 can be kept good, and excrement B and the like can be removed together with the sand 24. Can be discharged well. However, if the particle size of the sand is 100 micrometers or less, the sand may rise due to the water flow and the seawater may be contaminated.
In the case of a micrometer or more, there is a concern that the sand 24 may not move even under the condition of the water flow. However, when the flounder A seed is used for aquaculture and is large in size, for example, about 10 cm or more in length and the breeding density is high, this is not always the case.
Even if the particle size of 24 is 2,000 micrometers or more, in the case of Japanese flounder A with a total length of about 20 cm and a weight of about 100 to 150 g, there is not much problem with diving sand etc. A particle size of 2000 micrometers or more can be used.

In the water tank 1 of the embodiment, the bottom 7 and the outer peripheral plate 1
Since the concave arc portions 1B and 4A are formed at the first connection portion with the A and the second connection portion between the bottom 7 and the partition plate 4, respectively, the seeds of the flounder A at the connection portion are the arc portions 1B and 4A. So that collision of flounder A seeds and seedlings can be prevented.

Further, a second connecting portion between the bottom 7 formed on the concave arc portion 4A having a radius R of 50 to 100 mm, preferably 65 to 70 mm and the partition plate 4 and an air ejection pipe 12 are provided.
In addition to burying the air, the air ejection pipe 12 is provided with the air ejection holes 13 at intervals, so that even when the pump for sucking seawater breaks down and the water supply stops, the air is immediately discharged from the air ejection holes 13. By jetting, the supply of dissolved oxygen can be performed smoothly. Further, since the air ejection pipe 12 is buried in the arc portion 4A, smooth water flow is not hindered, and there is no danger that the cultured flounder A seeds directly collide with the air ejection pipe 12. In addition, since it is attached to the water tank 1 from the beginning, it is not necessary to quickly attach it when the medicine bath or the pump is stopped.

The present invention is not limited to the above-described embodiment. For example, as shown in FIG. 7, the drain 14 is disposed inside the water tank 1, and in the embodiment, the number of the drain 14 is four. However, the number may be increased or decreased. Furthermore, in the example, the case of flounder cultivation was shown, but flounder, crab,
It can also be used for aquatic animals such as shrimp, sea cucumber and shellfish, and aquatic plants such as seaweed. In particular, in the case of seagrass, it is necessary to provide at the bottom of the aquarium vegetation such as cobblestones and rocks with vegetation such as sand. In the embodiment, the nets 16, 17, and 18 are three. However, a plurality of nets may be used. In addition, the shape of the water tank 1 is, for example, the side wall of the embodiment is in a vertical state. It may be such that it is inclined so as to face. The replenishing sand 24B is supplied intermittently or continuously.
The replenishing position may be inserted downstream of the outlet 14. This is because when the sand 24B is supplied to the downstream side of the discharge port 14, the sand 24 moves to the discharge port 14 in the flow direction of the water flow X, and the sand 24 is deposited over the entire length of the bottom 7. is there.

[0031]

According to a first aspect of the present invention, there is provided a method of cultivating aquatic animals and plants by laying sand on the bottom of an aquarium for cultivating aquatic animals and plants, wherein a part of the bottom sands is removed from the aquarium by a water flow. By sequentially discharging and replenishing sand to the bottom of the aquarium, excrement of aquatic animals and plants can be discharged together with the sand, and the aquarium can be sanitized without damaging the aquatic animals and plants in the aquarium, and A method for culturing aquatic animals and plants that can be easily managed can be provided.

According to a second aspect of the present invention, the water tank is of a circulation type in which a water channel is formed in an annular shape, and the water is circulated by supplying the water in one direction of the circulation water channel.
And, by the circulating water flow, a part of the sand laid on the bottom together with the water is discharged from a discharge port provided at the bottom of the water tank. Sand can be sequentially discharged from the discharge port, and since the discharge port is provided at the bottom of the water tank, the sand naturally falls to the discharge port,
The sands do not soar, and aquatic animals and plants can be cultivated without making the water in the aquarium turbid.

[0033] A third aspect of the present invention is to provide a net having small holes in the outlet at the top and a net having large holes at the bottom, and cut the small net with the growth of aquatic animals and plants. By expressing the reticulated body having a large hole, the resistance of the drainage port can be reduced with the growth of aquatic animals and plants, and the reticulated body can be replaced without damaging the aquatic animals and plants.

A fourth aspect of the present invention is characterized in that the aquatic plants and animals use sand as a growth environment, and the excrement and the like are discharged by the sand to maintain the water tank in a sanitary manner. In addition, the sands can create a suitable growth environment for aquatic animals and plants.

According to a fifth aspect of the present invention, the sands have a particle size of 1.
By including the sand of 00 micrometers or more, the sand does not soar by the water flow to pollute the water, and the sand can be reliably discharged together with the excrement by the water flow.

According to a sixth aspect of the present invention, an outer peripheral plate is erected on the outer periphery of the bottom of the water tank, and a partition plate is provided at the center of the bottom to form an annular water passage, and a discharge port is provided at the bottom, and A water tank for culturing aquatic animals and plants, wherein a concave arc portion is formed in each of a first connection portion between the bottom and the outer peripheral plate and a second connection portion between the bottom and the partition plate. Since the aquatic plants and animals move along the arc, collision of the aquatic plants and plants can be prevented.

According to a seventh aspect of the present invention, an air ejection pipe is buried in a second connection portion formed in the concave arc portion, and air ejection holes are provided in the air ejection pipe at intervals. A water tank for culturing aquatic animals and plants according to claim 6, wherein air is immediately blown out from the air outlet even when water supply is stopped due to a failure of a water supply pump or the like, thereby reducing dissolved oxygen. Replenishment can be performed smoothly. In addition, since the air ejection pipe is buried in the arc portion, it does not hinder smooth water flow, and there is no danger that cultured aquatic plants or animals will directly collide with the air ejection pipe. In addition, since it is attached to the water tank from the beginning, it is not necessary to attach it in a hurry when taking a medicine bath or stopping the pump.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view around a discharge port showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a part around a water ejection pipe, which is an enlarged perspective view showing a part of the embodiment of the present invention.

FIG. 5 is a graph showing the particle size of the sand of the present invention.

FIG. 6 is a graph showing the particle size of another sand of the present invention.

FIG. 7 is a plan view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water tank 1A Outer circumference 1B 4A Arc part 5 Waterway 7 Bottom 12 Air ejection pipe 13 Air ejection hole 14 Outlet 16 17 18 Reticulated body 24 Sand A Flounder (aquatic animal) X Water flow

Claims (7)

[Claims] 1. A method for cultivating aquatic animals and plants by laying sand on the bottom of an aquarium for cultivating aquatic animals and plants, wherein a part of the sand on the bottom is sequentially discharged from the aquarium by a water stream and the bottom of the aquarium is cultivated. A method for cultivating aquatic animals and plants, comprising supplying sand to the sea. 2. The water tank is of a circulation type in which a water channel is formed in an annular shape. The water is circulated by supplying the water in one direction of the circulation water channel, and the water is circulated together with the water by the circulating water flow. 2. The method for cultivating aquatic animals and plants according to claim 1, wherein a part of the replenished sand laid on the bottom is sequentially discharged from a discharge port provided on the bottom of the water tank. 3. A reticulated body having a small hole is provided at an upper part of the outlet, and a reticulated body having a large hole is provided at a lower part. 3. The method for cultivating aquatic animals and plants according to claim 2, wherein 4. The method for cultivating aquatic animals and plants according to claim 2, wherein the aquatic animals and plants use sand as a growth environment. 5. The method for cultivating aquatic animals and plants according to claim 4, wherein said sands include sand having a particle diameter of 100 micrometers or more. 6. An outer peripheral plate is erected on the outer periphery of the bottom of the water tank, a partition plate is provided at the center of the bottom to form an annular water passage, a discharge port is provided at the bottom, and the bottom is connected to the outer peripheral plate. A water tank for cultivating aquatic animals and plants, wherein a concave arc portion is formed in each of the first connection portion and the second connection portion between the bottom and the partition plate. 7. An air ejection tube is buried in a second connecting portion formed in the concave arc portion, and air ejection holes are provided in the air ejection tube at intervals. 6. The aquarium for aquaculture of aquatic animals and plants according to 6.