JP2002125509A - Method for culturing water flea and apparatus for culturing aquatic microorganism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable aquatic microorganisms to be mass-cultured in a small-scale aquarium installation of about 1 ton. SOLUTION: This method for cultivating aquatic microorganisms by installing an air stone 24 in the water in a tank 1, and carrying out the aeration of the water to supply a water with dissolved oxygen comprises hanging a water-lifting cylinder 21 having openings at the top and the bottom in a state of having a distance from the bottom surface of the tank 1, inserting and installing the air stone 24 at the lower part of the water-lifting cylinder 21, installing an outer cylinder 22 having a water outlet 22a for discharging the water discharged from the upper side opening of the water-lifting cylinder 21, in the upper part of the water-lifting cylinder 21 so as to cover the cylinder 21, generating bubbles in the water-lifting cylinder 21 from the air stone 24 to air-lift the water in the water-lifting cylinder 21, flowing out the lifted water from the water outlet 22a into the water to generate a mild water flow in the whole water in the tank 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cultivating daphnia and a culture apparatus for aquatic micro-organisms. More particularly, in a feeding culture using an aquarium, a sufficient amount of oxygen is supplied to the whole water and aquatic micro-organisms are cultured. The present invention relates to a technique for increasing the culture density by dispersing living organisms and enabling large-scale culture using small-scale aquarium equipment.

[0002]

2. Description of the Related Art Aquatic microbes such as daphnia are used as live bait for hatching larvae such as carp and goldfish. There are two types of culture: fertilization culture that waits for dormant eggs of daphnia to hatch and proliferate, and feed culture in which daphnia seeds are placed in a pond or aquarium and fed with yeast and chlorella.

[0003]

However, the former of the above-mentioned conventional culture methods requires a large water surface and a large amount of water, and furthermore, since the growth is greatly influenced by the weather, a favorable growth environment is maintained. However, there is a problem that a stable culture amount cannot be secured over a long period of time. In addition, it was difficult to match the growth peak of daphnia with the hatching time of the fish, and the culture volume could not be adjusted to meet demand. In the latter,
Since the culture density was extremely low and a sufficient amount could not be obtained, it was not suitable for mass culture.

The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to provide a gentle water flow generating device to generate a gentle water flow in the whole water in a water tank. By supplying a sufficient amount of oxygen to the whole water and dispersing the aquatic micro-organisms, the culture density is increased, and large-scale culture of the aquatic micro-organisms is possible at any time with a small-scale aquarium equipment. An object of the present invention is to provide a method for cultivating a daphnia and a culture apparatus for aquatic micro-organisms capable of stably producing a feed for seeds and seedlings.

[0005]

In order to achieve the above object, in the method for cultivating daphnia according to the first aspect of the present invention, bubbles are generated from below the water tank through the cylinder, and the bubbles are passed through the cylinder and the water tank. A method for cultivating a daphnia that generates a gentle water flow throughout, wherein a first step of planting seeds in a first aquarium, a second step of planting seeds in a second aquarium after one day, and further one day A third step of planting seeds in a third aquarium, and a fourth step of harvesting the daphnia in the first aquarium one day later and again planting the seeds in the first aquarium; Repeat the fourth step,
It is characterized by continuous harvesting.

According to a second aspect of the present invention, there is provided an apparatus for culturing aquatic micro-organisms, wherein a water tank for storing water for culturing the aquatic micro-organisms is provided.
A cylinder provided in the water tank and having an opening at the top and bottom, an air bubble generating means inserted into the cylinder, and a water covering the upper part of the cylinder and discharging water discharged from an upper opening of the cylinder. The outlet is provided with a gentle water flow generating device comprising an outer cylinder provided in water.

According to a third aspect of the present invention, in the culture apparatus for aquatic micro-organisms according to the second aspect, a plurality of outlets are formed in the outer cylinder and are provided so as to generate water flows in opposite directions in the service water. It is characterized by having.

According to a fourth aspect of the present invention, in the culturing apparatus for aquatic micro-organisms according to the second or third aspect, a pipe for removing dirt is connected to an upper portion of the outer cylinder.

According to a fifth aspect of the present invention, in the cultivation apparatus for aquatic micro-organisms according to the second to fourth aspects, in the cultivation apparatus for the aquatic micro-organisms according to the third or fourth aspect, the flow rate of the gentle water flow is about 3 cm / sec or less. It is characterized by being.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a water flea (Moina macrocopa) is used as the aquatic micro-organism. To describe the physiological and ecological characteristics of Daphnia magna,
In nature, they multiply from spring to summer, and spend dormant eggs from autumn to winter, waiting for the next spring. Since spring, the water environment is good,
Parthenogenesis (female only) if food (feed) supply is appropriate
Proliferate in The mother of one Daphnia magna is several to 40,
It has 50 eggs (under favorable conditions) and produces pups. The produced larva becomes parent in 3 to 4 days and gives birth to the next generation. Sometimes it increases explosively, and it gathers on the surface and the water surface becomes deep red. Poor water quality and poor feeding conditions produce males and fertile eggs in females during sexual reproduction. The fertilized egg is covered by a hard membrane and floats on the surface of the water away from the mother or sinks to the bottom. This becomes a dormant egg and can withstand winter drying and freezing.

<First Embodiment> FIG. 1 is a diagram showing a configuration of a daphnia cultivation apparatus according to a first embodiment. In the figure, 1 is a tank (water tank), 2 is a gentle water flow generator, 3 is an air compressor, 4 is a waste pipe, 5 is a waste tank, 6 is a temperature sensor, 7 is a heater, and 8 is a feed supply container. .

The tank 1 stores water for cultivating daphnids, is formed in a short cylindrical shape with an open upper end, and is provided at the center of the side and bottom with a faucet 11a, 12a so as to be openable and closable. The mouths 11 and 12 are provided. Of these, the collection port 12 on the bottom side is closed from the inside by a rubber stopper 13 with a chain. An opening through which the gentle water flow generator 2 can be inserted is formed at the center of the lid 14 that is capped at the opening at the upper end of the tank 1, and a symmetrical position between the center and the periphery of the lid 14. Are provided with small openings into which the temperature sensor 6 and the heater 7 can be inserted.

The gentle water flow generating device 2 is for aeration of the water and for generating a gentle flow in the whole of the water. It is stopped by the frame that does not. More specifically, for example, using vinyl chloride, it is formed in a cylindrical shape having a double structure, and as shown in FIG. With the large and short outer cylinder 22 covered,
Both are fixed and integrated by a plurality of connecting members (not shown), and a substantially annular outlet 22 a at the lower end of the outer cylinder 22 as viewed from the bottom side of the tank 1 communicates with the upper opening of the pumping cylinder 21. It is provided in a state. Further, the upper opening of the outer cylinder 22 is tightly covered with a filth removing section 23 to which one end of the filth removing pipe 4 that communicates with the filth tank 5 is connected. Further, the upper end of the pumping cylinder 21 is located substantially at the center of the outer cylinder 22. When the gentle water flow generator 2 is set in the tank 1, the upper end of the pumping cylinder 21 is located substantially at the same height as the water surface. The upper half of the cylinder 22 projects upward from the water surface. Note that the upper end of the pumping cylinder 21 does not have to be at the same height as the water surface.

An air stone 24 is inserted into the lower end of the pumping cylinder 21. The air compressor 24 is connected to the air stone 24, and compressed air is supplied to the air stone 24 using the air compressor 3. By blowing, small bubbles are generated in the water in the water pumping cylinder 21, and aeration (aeration) is performed.

The filth tank 5 is a container in which the foamy filth generated at the upper end of the outer cylinder 22 of the gentle water flow generator 2 is stored after passing through the filth removing pipe 4.
The temperature sensor 6 is used for a thermostat for automatically turning on and off the power of the heater 7 in order to keep the temperature of water constant, and is generally used. The feed supply container 8 is for storing the feed of the daphnia and continuously feeding the daphnia little by little.

Next, the operation of the present embodiment will be described. When compressed air is supplied from the air compressor 3 to the air stone 24 provided at the lower end of the pumping cylinder 21 of the gentle water flow generator 2, the apparent specific gravity of the water in the pumping cylinder 21 becomes smaller than that of external water. The water surface 21 is lifted by an air lift and discharged from the upper opening. The water discharged from the upper opening of the water pumping cylinder 21 moves downward between the water pumping cylinder 21 and the outer cylinder 22 and flows out from the outlet 22a. Water is sucked into the pumping cylinder 21 from the lower opening.

By performing the above operation continuously, a gentle water flow in the direction of the arrow in FIG. 3 is generated in the whole water. Further, since the water flow is divided in opposite directions to form a collision surface, the speed of the water flow is suppressed to about 3 cm per second, which is the swimming speed of daphnia. Further, since the daphnia is hardly caught in the air lift by the collision surface, there is little obstacle to the proliferation. In addition, since the water aerated by the air stones 24 spreads over the entire water, a sufficient amount of oxygen is supplied to the entire water, and water flea, which easily aggregates on the water surface, is dispersed throughout the water, and a high culture density is secured. I have.

After the garbage such as excretions rises in the water pumping cylinder 21 together with the water, they are generated as bubbles in the outer cylinder 22 and the filth removing part 23 above the water surface (foam separation),
It is discharged to the waste tank 5 outside the tank 1 through the waste removal pipe 4 by the internal pressure. Therefore, the tank 1 is always kept in a clean state.

Next, a method for cultivating daphnia using the above-described culture apparatus will be described. Here, FIG. 4 is a diagram showing the growth process of daphnia in days, and FIG. 5 is a diagram showing the relationship between the growth time of daphnia and body length. As is clear from both figures, the daphnia is hatched from the egg. It takes three days to reach the first egg laying, and reproduction is possible in four days (two days in middle). In view of the above, in the present embodiment, three tanks 1 are installed to culture daphnia.

First, as a first step, a daphnia seed is planted in a first tank (day 1). Subsequently, as a second step, seeds are planted in a second tank after one day has passed (second day). At this time, the daphnia planted in the first tank is on the second day of culture. Next, as a third step, seeds are planted in a third tank after a further day has passed (day 3). Here, the daphnia in the first tank is on the third day of the culture, and the daphnia in the second tank is on the second day of the culture. Then, as a fourth step, after one day has passed, the daphnia in the first tank is harvested,
Seeds are again planted in the first tank (day 4). By repeatedly performing the first step to the fourth step,
As shown in FIG. 6, a constant amount of daphnia can be continuously harvested daily using the three tanks 1, and the feed for seeds and seedlings can be stably supplied every day.

Next, another embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. <Embodiment 2> FIG. 7 is a perspective view showing a configuration of a slow water flow generating apparatus of Embodiment 2 and FIG. 8 is an explanatory view showing the operation of a daphnia cultivation apparatus of Embodiment 2. The gentle water flow generation device 9 of the present embodiment has a structure in which a middle cylinder 92 shorter than the pumping cylinder 91 is provided between the pumping cylinder 91 and the outer cylinder 93. Pumping cylinder 91 and middle cylinder 92, and middle cylinder 92 and outer cylinder 9
Reference numeral 3 is fixed by a connecting member (not shown). At the lower ends of the middle cylinder 92 and the outer cylinder 93, substantially annular outlets 92a and 93a are provided, respectively, as viewed from the bottom side of the tank 1, and these are communicated with the upper openings of the water pumping cylinder 91, respectively.

In the gentle water flow generator 9 of the present embodiment, the water discharged from the upper end of the pumping cylinder 91 is
Through the middle cylinder 92 and the outer cylinder 93
The water flows out of the two outlets 92a and 93a, respectively, and generates a gentle water flow as shown by arrows in FIG.

<Embodiment 3> FIG. 9 is a perspective view showing a configuration of a slow water flow generating apparatus according to Embodiment 3 and FIG. 10 is an explanatory view showing the operation of a daphnia cultivation apparatus according to Embodiment 3. The gentle water flow generation device 10 of the present embodiment has a structure in which an inner cylinder 102 is provided between a pumping cylinder 101 and an outer cylinder 103, and a water rising cylinder 104 is provided outside the outer cylinder 103. . A substantially annular outlet 102a is provided at the lower end of the inner cylinder 102 when viewed from the bottom side of the tank 1,
A substantially annular outlet 104 a is provided at the upper end of the tank 4 when viewed from above the tank 1.

In the slow water flow generator 10 of the present embodiment,
The water discharged from the upper end of the water pumping cylinder 101 passes through the space between the water pumping cylinder 101 and the inner cylinder 102 and flows out of the outlet 102a. It goes upward, passes between the outer cylinder 103 and the water-raising cylinder 104, and flows out from the outlet 104a. As shown in FIG. 10, the water flowing out of the two outlets 102a and 104a generates water flows in opposite directions in the service water, so that the two water flows interfere with each other to form the water flow in the service water more gently. be able to.

[0025]

Next, the present invention will be described in more detail with reference to examples. <Example 1> A tank 1 having a capacity of 500 liters was prepared.
Slow water flow generator 2, 9, 1 in each of the above embodiments
0 was used to conduct a three-day Daphnia magna culture test.
At the same time, the same test was performed in the case where the air stone was exposed to water and weak aeration was performed without using the slow water flow generator, and in the case where strong aeration was performed. Freshwater concentrated chlorella was used as a feed for the water flea, and the culture water temperature was set at 28 ° C. Table 1 shows the test results. In the table, the slow water flow generators 2, 9, and 10 are referred to as I
Type, type II, and type III. In general, the number of daphnia per 1 g of wet weight is determined by the seed daphnia (5
4,800 individuals, harvested daphnia (3
The remaining 50 μ net is 5,800 individuals, but at the cultivation site, the total is 4,000 individuals and 5,000 individuals, respectively.

[0026]

[Table 1]

As shown in Table 1, better proliferation was observed when the slow water flow generator was used as compared with the case where the culture was performed only by aeration. Specifically, when the type III (slow water flow generator 10) is used, the yield is 2,90.
0g is the best result. Next, it is 2,850 g using the type II (slow water flow generator 9) and 2,150 g using the type I (slow water flow generator 2). 1,9
00g and 800g only with weak aeration. In addition, the harvest amount of only strong aeration was large in garbage, and the actual harvest amount was about half. This is because, when the airstone is exposed in water and strong aeration is performed, the water flow becomes too fast, and a part of the daphnia is killed, thereby inhibiting the growth.

<Example 2> Next, for Type I and Type III, a tank 1 having a capacity of 1,000 liters was subjected to a 3-day culture test. The main running costs when using a 1,000 liter tank are as follows. 1kW electric heater x 3 sets (3kW) 720w air compressor x 3 units or 900w
× 2 units (2.16 kW or 1.8 kW) When chlorella is used as feed, 1 kg of daphnia (500
1 liter of concentrated chlorella per production (10,000 individuals) (6k
g: Chlorella 6 liters for 30 million individuals) Table 2 shows the test results.

[0029]

[Table 2]

As a result, 1.5 kg or less after 3 days of culture
From the seed weight of 1.6 kg (620-6.4 million individuals),
5-7.6kg (355μ net filtration: 2,750
(38 million individuals) were obtained.

<Economic Effect> Here, the economic effect of the daphnia cultivation apparatus of the present embodiment will be described by comparing the area with the carp production (conventional type) of daphnia fertilization culture. By using the culture device of the present embodiment, as apparent from the above Example 2, it is possible to culture 30 million individuals / day in a 1,000-liter tank set (three water tanks). It is possible to produce about 1 million fry per gram. And the required size of the fry pond is 100-200
requires only m ² about. In normal fertilization culture, fertilizer culture fry pond required for the production of 1 million fishes is about 30,000 m ^2.
(3,000 fish per 100 m ² ). Therefore, the seedling production is 1/300 to 1 /
This is possible with 150 small ponds, and the existing fry ponds can be reduced or converted to training ponds to increase production.

<Prospects for application development of this device> Although daphnia lives only 3 to 5 minutes in seawater, it is possible to fortify DHA and ERA, and it is used as it is for marine fish with active feeding. be able to. In addition, shrimp and crabs can feed on dead food, and there is a high possibility that frozen daphnia can be used. Successful cultivation of marine daphnia (Diaphanosoma celebensis) will greatly expand its use in marine fish and crustaceans.

Although the embodiments of the present invention have been described above, the specific configuration of the present invention is not limited to the embodiments, and a design change or the like may be made without departing from the gist of the invention. Even if present, it is included in the present invention. For example, in the present embodiment, the water flea was used as the aquatic micro-organism,
The culture device of the present invention can be applied to other aquatic micro-organisms. In addition, the shape and size of the gentle water flow generation device are arbitrary, and the position and shape of the outlet can be arbitrarily set as long as a gentle water flow can be generated in the entire service water. Further, in the present embodiment, the air compressor is used as the supply source of the compressed air, but the supply source of the compressed air can be set arbitrarily. Further, a configuration may be employed in which compressed oxygen is supplied using an oxygen generator.

The mode for setting the slow water flow generation device is not limited to the configuration in which the gentle water flow generation device is hung from above the tank as in the present embodiment, but may be fixed to the tank lid or the lower end of the pumping cylinder to the tank. An opening may be provided in the peripheral portion. The most preferable shape of the tank is a cylindrical shape, but the same effect can be obtained with a general rectangular parallelepiped water tank. Furthermore, it is preferable that the bubble generating means insertion position of the pumping cylinder is as close as possible to the lower end of the pumping cylinder, but unless the position is close to the water surface so that air lift becomes impossible.
It can be placed anywhere.

[0035]

According to the daphnia cultivation method of the present invention, a certain amount of daphnia can be continuously harvested daily using three aquariums, and the daphnia can be cultured relatively easily. Since the growth rate is high, the effect of continuously and stably supplying feed for seeds and seedlings as live feed for hatching larvae such as carp and goldfish can be obtained.

In the culture device for aquatic micro-organisms according to the present invention, the water in the water tank is aerated by the bubble generating means, and at the same time, the inside of the cylinder is air-lifted. By generating water, a sufficient amount of oxygen can be distributed to the entire service water, and aquatic micro-organisms that easily gather on the water surface are dispersed throughout the service water,
Culture density can be increased. Therefore, even in small-scale aquarium equipment, large-scale cultivation of aquatic microbes becomes possible,
In addition, since it is not affected by the weather, a sufficient amount of feed for seeds and seedlings can be stably produced over a long period of time.

By providing a plurality of outlets so as to generate water flows in opposite directions, the gentle water flow can be made more gentle. Furthermore, by connecting the waste removal pipe to the outer cylinder covered by the cylinder, the waste generated at the upper part of the outer cylinder is discharged out of the water tank through the pipe by the internal pressure in the outer cylinder. In addition, the water tank can be always kept in a clean state, and the trouble of cleaning can be saved. And, by setting the flow rate of the gentle water flow to about 3 cm per second, which is the swimming speed of daphnia, the killing of daphnia can be reduced and obstruction to the growth can be eliminated as compared with the conventional feeding culture using only aeration. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a daphnia cultivation apparatus according to a first embodiment.

FIG. 2 is a perspective view illustrating a configuration of a gentle water flow generation device according to the first embodiment.

FIG. 3 is an explanatory view showing the operation of the daphnia cultivation apparatus of the first embodiment.

FIG. 4 is a diagram showing the growth process of daphnia in days.

FIG. 5 is a diagram showing the relationship between the growth time and body length of daphnia.

FIG. 6 is a diagram showing a method of harvesting daphnia daily using three tanks.

FIG. 7 is a perspective view illustrating a configuration of a gentle water flow generation device according to a second embodiment.

FIG. 8 is an explanatory view showing the operation of the daphnia cultivation apparatus according to the second embodiment.

FIG. 9 is a perspective view showing a configuration of a gentle water flow generation device according to a third embodiment.

FIG. 10 is an explanatory view showing the operation of the daphnia cultivation apparatus according to the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank 11,12 Collection port 11a, 12a Faucet 13 Rubber stopper 14 Lid 2 Slow water flow generator 21 Pumping cylinder 22 Outer cylinder 23 Soil removal part 24 Air stone 3 Air compressor 4 Soil removal pipe 5 Soil tank 6 Temperature sensor 7 Heater 8 Food feeder 9 Slow water flow generator 91 Pumping cylinder 92 Middle cylinder 92a, 93a Outlet 93 Outer cylinder 10 Slow water flow generator 101 Pumping cylinder 102 Inner cylinder 102a, 104a Outlet 103 Outer cylinder 104 Elevating cylinder

Claims (5)

[Claims] 1. A daphnia cultivation method in which bubbles are generated from below a water tank through a cylinder, and a gentle water flow is generated in the cylinder and in the entire water tank by passage of the bubbles. A second step of planting seeds in a second aquarium one day later, a third step of planting seeds in a third aquarium one day later, and a daphnia in the first aquarium one day further. A fourth step of harvesting and planting seeds in the first water tank again, wherein the first to fourth steps are repeated to continuously harvest the water flea. 2. A water tank for storing water for culturing aquatic micro-organisms, a cylinder provided in the water tank and having upper and lower openings, an air bubble generating means inserted in the cylinder, An aquatic micro-organism characterized by comprising a gentle water flow generator comprising an outer cylinder provided with an outlet provided in the water, wherein the outlet for discharging water discharged from the upper opening of the cylinder is provided on the upper part. Culture device. 3. The culture apparatus for aquatic micro-organisms according to claim 2, wherein a plurality of outlets are formed in the outer cylinder, and are provided so as to generate water flows in opposite directions in the service water. 4. The apparatus for culturing aquatic micro-organisms according to claim 3, wherein a waste pipe is connected to an upper portion of the outer cylinder. 5. The apparatus for culturing aquatic micro-organisms according to claim 3, wherein the flow rate of the gentle water flow is about 3 cm / sec or less.