JPH08308429A - Cultivation of demersal fish and apparatus therefor - Google Patents

Abstract

PURPOSE: To provide a culture method and an apparatus capable of getting a grown fish free from non-homogeneous pattern on the reverse face such as a natural flounder. CONSTITUTION: Flounders F are cultured in a culture space S encircled with a curtain-like partition W formed by continuously blowing bubbles from a bubble ejection pipe 1 laid on the bottom of the sea. Since the light incident on the sea surface reaches the bottom of the sea after repeated reflection and refraction with the bubbles of the curtain-like partition W, the grown flounder F is free from spots and mottled pattern on the reverse face of the body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cultivating a fish such as a flatfish, a flatfish, etc.

[0002]

2. Description of the Prior Art Fish that live on the seabed, such as flounder and flatfish,
So-called bottom fish has the property of discoloring the body surface depending on the surrounding environment. Originally, when the light is reflected by natural light, the surface on the front side becomes dark brown and the surface on the back side is shown in FIG.
As shown in, it is almost solid white.

However, when aquaculture is performed using cages,
Due to the shadow of the cage cage's movement on the surface of the body, it has the property of producing a light gray pattern on the back side. Then, after several months, the pattern becomes darker, and after one year or more, it becomes a black-and-white spot pattern as shown in FIG. 2 (B), which cannot be restored even if it is moved to a shadowless environment. Bottom fish such as Japanese flounder, which has a spotted pattern on the back side and is not white,
In the market, the product value is low.

[0004]

In this way, the flounder cultivated by the conventional method has a low commercial value and a low unit price, so that there is a problem that it has no choice but to rely on natural ones.
From the viewpoint of promoting the fishery and protecting the environment, the development of excellent aquaculture technology has been awaited.

The present invention has been made for the purpose of providing an aquaculture method and apparatus capable of obtaining an adult fish such as a natural flounder which does not have a non-uniform pattern on its back surface.

[0006]

According to the aquaculture method of the invention of claim 1, in the aquaculture method of aquaculture a bottom fish in a culture area surrounded by a partition from the seabed to a predetermined depth, bubbles are generated from a plurality of parts of the seabed. At least a part of the aquaculture area was surrounded by a curtain-shaped partition formed by continuously discharging the fish, and the bottom fish was aquacultured in the aquaculture area.

According to a second aspect of the present invention, in the aquaculture device for aquaculture a bottom fish in the aquaculture area surrounded by the partition from the seabed to a predetermined depth, a bubble discharge nozzle arranged linearly on the seabed. A gas pressure feeder, and a gas supply pipe connecting the gas pressure feeder and the bubble discharge nozzle in communication with each other,
Means were provided to provide a floating body arranged on the sea surface corresponding to the bubble discharge nozzle.

[0008]

According to the aquaculture method of the first aspect of the present invention, in the aquaculture method for aquaculture a bottom fish in the aquaculture area surrounded by the partition from the seabed to a predetermined depth, bubbles are continuously discharged from a plurality of parts of the seabed. Since at least a part of the aquaculture area is surrounded by the curtain-shaped partition formed by the above, it becomes easy for the light on the sea surface to reach the sea bottom while being repeatedly reflected / refracted by each bubble of the curtain-shaped partition.

Therefore, uniform light is given to the bottom fish inhabiting the seabed without giving a shadow. And claim 2
According to the aquaculture device of the invention of claim 1, in the aquaculture device for aquaculture the bottom fish in the aquaculture area surrounded by the partition from the seabed to a predetermined depth, continuous bubbles are generated from the bubble discharge nozzle linearly arranged on the seabed. The curtain-shaped partition is formed by discharging the light in a circular manner, and at least a part of the aquaculture area is surrounded by the partition, so that the light on the sea surface reaches the sea bottom while being repeatedly reflected / refracted by each bubble of the curtain-shaped partition. It will be easier.

Therefore, the uniform light is given to the bottom fish inhabiting the seabed without giving a shadow. Further, since the floating body is arranged at the position on the sea surface corresponding to the bubble discharge nozzle, a large number of nocturnal insects gather on the floating body in the dark night. In the same manner as described above, the light of the nocturnal insect easily reaches the sea floor while being repeatedly reflected / refracted by each bubble in the curtain-shaped partition.

Therefore, the uniform light is given to the bottom fish inhabiting the seabed without giving a shadow. In this way,
Since there is no shadow of the net in the cage and the light from the sea surface reaches the bottom of the sea, unevenness such as spots does not occur on the back surface of the bottom fish that inhabits the bottom of the sea.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method and apparatus for cultivating bottom fish according to the present invention will be described in detail below with reference to the drawings showing the embodiments.

FIG. 1 is a view showing the structure of a bottom fish culturing apparatus of this embodiment. In the figure, reference numeral 1 is a bubble discharge pipe arranged in a rectangular shape surrounding a predetermined aquaculture area S on the seabed, and a large number of bubble discharge nozzles 11 are formed. Reference numeral 2 denotes a compressor as a gas pressure feeder, which generates a pressure necessary for discharging gas from the bubble discharging nozzle 11.

Reference numeral 3 is a compressor 2 and the bubble discharge pipe 1
A gas supply pipe 4 for communicating with the bubble discharge pipe 1
The floating bodies are arranged in a rectangular shape on the sea surface corresponding to the arrangement of. The bubble discharge pipe 1 is sunk on the seabed and is anchored so as not to be washed away by the tidal current. The bubble discharge nozzle 11 and the bubble discharge pipe 1 are connected via a joint by a connecting pipe thinner than the bubble discharge pipe 1. Bubble discharge nozzle
An air release valve is provided in the vicinity of 11 so that the nozzles can be uniformly discharged. Also, the bubble discharge pipe 1
The bubble discharge pipe 1 and the floating body 4 on the sea surface are connected to each other by a minimum number of transparent ropes in order to pull up.

On the surface of the sea, a large number of floating bodies 4 are connected to each other by ropes and serve as a mark for the aquaculture area S.
In the machine room 5 installed near the shore or the sea, the compressor 2, the electric motor or engine of the power source thereof, their control mechanism, the oxygen cylinder 6 and the like are arranged.

The gas supply pipe 3 is preferably a pressure hose or a pressure pipe having corrosion resistance against seawater corrosion, mechanical strength against pressure and tidal current, and flexibility capable of absorbing some movement. . 7 is a colorless and transparent net, which is arranged so as to surround the seabed up to a height of about 2 m.

In the bottom fish farming apparatus 10 having the above configuration,
The air compressed by operating the compressor 2 is guided to the bubble discharge pipe 1 through the gas supply pipe 3 and discharged into the sea from the bubble discharge nozzle 11. The discharged bubbles form a vertical curtain-shaped partition W having the bubble discharge pipe 1 as the bottom and a rope connecting the floating body 4 on the sea surface as the top when rising in the sea by buoyancy.

In the aquaculture area S surrounded by the partition W thus formed, the bottom fish F such as flounder is aquacultured.

In the aquaculture area S thus formed,
The transparent and transparent net 7 does not cast a shadow on the bottom fish F such as the flounder that inhabits the seabed, and the light near the sea surface is reflected / refracted by many bubbles continuously existing from the sea surface to the sea floor. As it repeats, it reaches the seabed along the curtain-shaped partition W and gives a uniform brightness, so that the pattern of spots or the like does not occur on the body surface of the bottom fish F such as the flounder and the like, as shown in FIG. As shown, the back side is almost solid white.

The curtain-shaped partition W thus formed is
In addition to the effect of delivering light to the seabed, it also has an effect of preventing fry and small fish existing inside the aquaculture area S from being dispersed outside the aquaculture area S because it is shining white. Therefore, the colorless and transparent mesh 7 can be omitted. Further, since it is possible to set a desired area as the aquaculture area simply by installing the gas supply pipe 3, the convenience as a mobile cage can be obtained.

Further, at night, the moonlight illuminating the sea surface reaches the sea bottom along the curtain-shaped partition W in the same manner as described above. In the dark night when the moon does not appear, a large number of nocturnal insects gather on the floating body on the surface of the sea and the ropes that connect the floating body to the sea floor along the curtain-shaped partition W in the same manner as described above.

Further, since it is advisable to mix a small amount of oxygen in order to prevent blockage of the bubble discharge nozzle, it is advisable to open the oxygen cylinder 6 occasionally to mix oxygen with air and then discharge from the nozzle.

Although it is preferable that the entire circumference of the aquaculture area S is surrounded by the curtain-shaped partition W, a part of the aquaculture area S may be enclosed by utilizing natural topography depending on the environmental conditions of the aquaculture place. However, in order not to cast a shadow on the seabed of the aquaculture area S, it is necessary to arrange the curtain-shaped partition W only on the south side, on both the east and west sides, or on the north side depending on the season.

The action and effect according to the present invention is remarkable in the flounder, but the same action and effect can be expected in other flatfish of the flatfish family.

[0025]

According to the invention of claim 1, since the curtain-shaped partition formed by the bubbles allows the light of the sea surface to reach the seabed, the bottom fish inhabiting the seabed has a shadow such as a net of a cage. A uniform light is given without moving. Therefore, an uneven pattern such as a speckled pattern is prevented from being formed on the back surface of the bottom fish inhabiting the seabed, and it is possible to cultivate the bottom fish having a high market value.

According to the second aspect of the present invention, it is possible to obtain the effect that the aquaculture method that achieves the above effects can be efficiently realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of a culture apparatus used in a method for cultivating bottom fish according to the present invention.

FIG. 2 is a diagram showing a state of a back side surface of flounder.

[Explanation of symbols]

 W Partition S Culture area F Bottom fish 1 Bubble discharge pipe 11 Bubble discharge nozzle 2 Gas pump (compressor) 3 Gas supply pipe 4 Floating body 10 Bottom fish culture equipment

Claims (2)

[Claims] 1. A culture method for cultivating bottom fish in a culture area surrounded by a partition from the seabed to a predetermined depth,
A method for cultivating bottom fish, wherein at least a part of the culturing area is surrounded by a curtain-shaped partition formed by continuously discharging bubbles from a plurality of parts of the seabed, and the bottom fish is cultivated in the culturing area. 2. A culture apparatus for cultivating bottom fish in a culture area surrounded by a partition from the seabed to a predetermined depth, wherein a bubble discharge nozzle linearly arranged on the seabed, a gas pressure feeder, and a gas pressure feeder. An aquaculture device for bottom fish, comprising: a gas supply pipe that connects the vessel and the bubble discharge nozzle for communication; and a floating body arranged on the sea surface corresponding to the bubble discharge nozzle.