JP2002000119A - Method for culturing fish and shellfish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for culturing fishes and shellfishes in which a sufficient amount of dissolved oxygen can be supplied for the fishes and shellfishes at low cost, excellent in feeding efficiency, and by which the fishes and shellfishes can grow as rapidly as possible. SOLUTION: Fishes and shellfishes are cultured in an environment where air of bubbles having diameters of <=20 μm is supplied. Further, the culturing is carried out in an environment where ultrasonic waves are charged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fish and shellfish having a diameter of 20 μm.
The present invention relates to a method for cultivating fish and shellfish, wherein the cultivation is performed in an environment in which air of m or less bubbles (hereinafter also referred to as microbubbles in the present specification) is supplied. In addition, the present invention relates to a method for cultivating fish and shellfish, wherein the cultivation is performed in an environment where ultrasonic waves are supplied.

[0002]

2. Description of the Related Art Conventionally, the cultivation of fish and shellfish is carried out by filling a culture tank or a pond with natural or artificial seawater or freshwater and supplying air by an appropriate method, and repeatedly changing water as necessary. Problems encountered in aquaculture include maintenance of sufficient dissolved oxygen in the aquaculture water, treatment of residual food and feces, cannibalism due to fish fighting, and reduced activity of fish and shellfish due to bacteria and parasites. There is no definitive solution yet.

[0003]

In the cultivation of fish and shellfish, the amount of dissolved oxygen that satisfies the requirements of fish and shellfish can be supplied at low cost, the feeding efficiency is excellent, the growth rate is excellent, and the adult fish can be cultured in a short period of time. There is a need to develop new aquaculture methods.

[0004]

The inventors of the present invention have made intensive studies to solve the above-mentioned problems. As a result, the use of bubbles having a diameter of 20 μm or less generated by a swirling bubble generator not only solves the problem of dissolved oxygen but also replaces water. It was found that the frequency of slaughter was greatly reduced, and the treatment of residual food and feces became easier. In addition, it was found that the use of ultrasonic waves solved the problem of cannibalism of fish, and increased the catch, reduced equipment costs, and simplified management compared to the conventional method. According to the present invention, there is provided a method for cultivating fish and shellfish, which comprises culturing fish and shellfish in an environment in which air bubbles having a diameter of 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less are supplied. . In addition, there is provided a method of culturing fish and shellfish, wherein the fish and shellfish are cultivated in an environment where ultrasonic waves are supplied. Furthermore, when a swirling type bubble generator is used as a bubble supply device, since ultrasonic waves are generated simultaneously with the generation of microbubbles, it is not necessary to prepare an ultrasonic generator again, and it is possible to culture the fish very effectively. it can.

[0005] Aspects of the present invention are set forth below. (1) A method of cultivating fish and shellfish, wherein the fish and shellfish are cultivated in an environment where air having a bubble diameter of 20 μm or less is supplied. (2) The method according to (1), wherein the culturing is further performed in an environment supplied with ultrasonic waves. (3) The method according to (2), wherein the wavelength of the ultrasonic wave is between 10 MHz and 30 MHz. (4) The method according to any one of (1) to (3), wherein the culturing is performed in a culturing tank. (5) The method according to any one of (1) to (4), wherein the bubble is a bubble generated by a swirling bubble generator. (6) The method according to (5), wherein the swirling bubble generator is provided in a culture tank. (7) The method according to (5), wherein the swirling bubble generator is provided outside the culture tank. (8) Fish and shellfish are tuna, tuna, amberjack, gibberfish,
One species selected from sea bream, puffer fish, flounder, sea bass, horse mackerel, oysters, oyster shellfish, shrimp, abalone, trout and sweetfish (1)
The method according to any one of (1) to (7).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The air bubbles used in the present invention are fine bubbles having a diameter of 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less. According to the method of the present invention, since the bubbles are small compared to the conventional method, for example, bubbles due to ceramic air stone, the residence time of the bubbles in the liquid is long, the gas-liquid contact efficiency is high, and the high Dissolved oxygen concentration can be maintained. As a device for generating bubbles, any device can be used as long as it can generate fine bubbles.
O9933353). The bubbles generated by this device have a diameter of 20
It has a size of μm or less, and is preferable as the bubble generator of the present invention.

[0007] The ultrasonic wave in the method of the present invention is 10
Ultrasonic waves having a wavelength between MHz and 30 MHz are preferably used, and any known ultrasonic wave generator can be used. As the device, preferably, the above-mentioned revolving microbubble generator which generates ultrasonic waves simultaneously with microbubbles is used. By using such a device, there is no need to prepare an ultrasonic generator again, which is extremely advantageous.

[0008] Fish and shellfish to which the method of the present invention can be applied include:
Any fish and shellfish that can be cultivated may be used, for example, yellowtail, tuna, amberjack, leek, sea bream, puffer fish, flounder, sea bass, horse mackerel, oyster, oyster shellfish, shrimp, abalone, trout,
Ayu etc. are shown.

The water used in the method of the present invention is not particularly limited as long as it is suitable for the fish and shellfish to be cultured. For example, natural or artificial seawater is used for saltwater fish, and natural or artificial freshwater is used for freshwater fish. The aquaculture water is stimulated and activated by changing the water as needed. Conventional replacement is usually 1
It is performed 5 to 10 times a day, but can be reduced to 2 to 3 times a day in the method of the present invention. The frequency of water change is also related to the amount of residual food or feces, and can be further reduced by providing a floating material recovery device described later.

[0010] When aquaculture is carried out using a culture tank, a revolving microbubble generator may be provided inside the tank, but it is more convenient to provide it outside the tank from the viewpoint of equipment management and the like. In this method, the air is supplied to the piping in front of the circulation pump, and a revolving microbubble generator is provided at the outlet of the circulation pump to supply the air as fine bubbles to the culture tank. Is more preferable.

In the aquaculture tank, air bubbles rise slowly and gas-liquid contact takes place, so that oxygen is dissolved. Therefore, it is possible to obtain a sufficient amount of dissolved oxygen with a smaller air supply than in the method using a ceramic airstone. it can. At the same time, microbubbles adhere to the bait or feces remaining in the tank and accompany them, and float. Because the air bubbles are small, they adhere to fine solids and float, so a floating material recovery device is installed at the top of the culture tank,
It is convenient to collect the floating material because the culture water can be purified.

[0012]

The embodiments of the present invention will be described by way of examples. Example 1 Two approximately 10 kl culture tanks are used as culture tanks, and air is generated by a conventional process air (air is blown by a compressor and ceramic air stone is blown into one of the culture tanks containing 8 kl of seawater). Air generated by the method, the air bubbles are supplied with a diameter of about 200 μm or more, while the microbubbles are supplied using a swirling microbubble generator (the size of the air bubbles is 20 μm or less) to supply the red sea bream. An aquaculture test was performed. Air was supplied so that the dissolved oxygen in the seawater in the aquaculture tank was maintained at 6 to 7 mg / l, the rate of water exchange was set at 2.5 revolutions / day, and the feeding method was satiety feeding at 3 times / day. The results shown in Table 1 were obtained by measurement 35 days after the start of aquaculture.

[0013]

[Table 1] Feeding rate and growth rate show the values for the average day. Characteristic matter by observation In the present invention zone, fish swim slowly, form a row and swim as a group, and a generally mild impression was observed.The feeding behavior was not active and switched to process air. He instantly returned to his original swim and swam randomly.

Example 2 600 tiger pufferfish (average body length: 16.5 mm, average body weight: 180 mg), 40 days old, were placed in a 1 kl culture tank at 0.8 k
One (conventional method) uses process air, and the other (the method of the present invention) uses microbubbles to maintain the dissolved oxygen in the seawater in the culture tank at 6 to 7 mg / l. Air was supplied as described above, the water exchange rate was set at 2.5 revolutions / day, and the feeding method was 3 times / day under the culture conditions of satiety feeding. On the 14th day (54 days of age) of the aquaculture, 50 animals in each aquaculture tank were randomly taken out and measured. As a result, the average length of the present group was 31.8 and the average weight was 1346 mg, whereas the average length of the control group was 29.6 mm. The average body weight was 1062 mg. The degree of tail fin loss was visually observed, and the results are shown in Table 2.
Shown in

[0015]

[Table 2] It was observed that the group of the present invention not only had a higher tail fin residual ratio than the control group, but also was superior to the residual ratio at the start.

[0016]

As described above, the microbubbles have a long residence time in water, so that the amount of oxygen dissolved in the supplied air increases.
As a result, the required dissolved oxygen can be maintained with a smaller amount of air. Since surplus food and feces in the culture water float with the microbubbles, purification of the culture water can be achieved by providing a simple suspended matter recovery device. Therefore, a large-scale purification device becomes unnecessary, and the number of times of water replacement is reduced,
An effect such as reduction of labor costs can be expected. With the effect that microbubbles adhere to the skin of fish and wash off dirt on the surface of the skin when it pops,
Ultrasound provides the effects of improving blood flow and strengthening the skin of the fish, suppressing the growth of bacteria in water, and preventing the attachment of parasites. Under the environment where the ultrasonic waves are supplied, the swimming of the fish is gentle, and the fish form a row and swim in a group. Therefore, it can be understood that there is no fight between the fish and the environment is comfortable for the fish. The overall effect is to increase catches by improving growth rates and feed efficiency.

Claims (8)

[Claims] 1. A method for cultivating fish and shellfish, wherein the fish and shellfish are cultivated in an environment in which air of bubbles having a diameter of 20 μm or less is supplied. 2. The method according to claim 1, wherein the culturing is performed in an environment supplied with ultrasonic waves. 3. The ultrasonic wave has a wavelength of 10 MHz to 30 MHz.
3. The method of claim 2, wherein 4. The method according to claim 1, wherein the culturing is performed in a culturing tank.
4. The method according to any one of the above items 3. 5. The method according to claim 1, wherein the bubbles are bubbles generated by a swirling bubble generator. 6. The method of claim 5, wherein said swirling bubble generator is provided in said culture tank. 7. The method according to claim 5, wherein the swirling bubble generator is provided outside the culture tank. 8. The fish and shellfish is one selected from hamachi, tuna, amberjack, gibberfish, snapper, puffer fish, flounder, sea bass, horse mackerel, oyster, oyster shellfish, shrimp, abalone, trout and sweetfish. The method according to any one of claims 1 to 4.