JP2017023023A - Seafood anesthetization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seafood anesthetization method hardly deteriorating the quality of seafood although using a compact and simple device, capable of anesthetizing for a short time period, and capable of maintaining the anesthetization stably for a prolonged period.SOLUTION: An anesthetization method according to the invention comprises: an anesthetization step of dissolving carbon dioxide of a predetermined quantity necessary for anesthetization of a seafood in water; and an oxygen super-saturation step of keeping the oxygen dissolved in water in a super-saturation state. At the oxygen super-saturation step, the quantity of dissolved oxygen in water is kept at 12 mg/l or more in a prescribed proper water temperature region of each seafood.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for anesthetizing fish and shellfish. More specifically, the present invention relates to a method for anesthetizing fish and shellfish that can be used to make anesthesia in a short time and stably maintain anesthesia over a long period of time while using a compact and simple device.

  Traditionally, when a fish is exposed in a fish farm, such as when vaccination is used to prevent disease, biting is performed to prevent biting, labeling, weight measurement, or when live fish is transported, Since this leads to a decline in sex, damage to the fish body, and a decrease in fish life activity, there is a need for a technique for anesthetizing and quieting the fish.

  However, among anesthesia techniques, in the case of anesthesia with drugs, foreign substances such as drug components may remain in the body of the fish and the quality may deteriorate. In the case of low-temperature anesthesia that gradually lowers the body temperature of fish to reduce metabolism, it takes a long time until the fish is anesthetized, and a large-scale device is also required. For this reason, anesthesia technology using carbon dioxide is currently attracting attention.

  Regarding the carbon dioxide anesthesia technology, an anesthetic carbonated water containing dissolved carbon dioxide having an anesthetic effect and dissolved oxygen (Dissolved Oxygen) at a concentration necessary for the fish to survive is prepared in advance. A technique of supplying anesthesia carbonated water to an aquarium and putting fish into it for anesthesia is known (for example, see Patent Document 1).

  Furthermore, carbon dioxide is ventilated into the water in the aquarium, and dissolved carbon dioxide is raised to a concentration having an anesthetic effect. At the same time, fine oxygen bubbles are continuously supplied into the water, and oxygen bubbles are brought into direct contact with the fish cage. Thus, a technique for applying anesthesia is also known (see, for example, Patent Document 2).

JP 2008-54559 A JP 2014-39514 A

  However, in the former technique, since the concentration of dissolved oxygen (hereinafter referred to as “the amount of dissolved oxygen”) DO is as small as 1.5 mg / l or more and the saturated oxygen concentration or less, for example, the amount of oxygen absorbed from soot is also low. Few. For this reason, the oxygen demand of each individual fish cannot be sufficiently satisfied, and the elapsed time from the start of anesthesia to the death of the fish (hereinafter referred to as “anesthetic limit time”) is 20 at the longest. Minute and short.

  In particular, when transporting raw fish, it is generally necessary to continue for at least 5 hours (hereinafter referred to as “required anesthesia time”) even if the state of anesthesia is short. Fish dying due to respiratory failure. In the following description, all dissolved gas amounts are values under 1 atm.

  In the latter technique, since oxygen bubbles need to be in direct contact with the fish cage, the oxygen bubbles are supplied accurately and continuously throughout the aquarium where the fish is active until anesthesia is applied. There must be.

  For this reason, it is indispensable to provide a complicated and large oxygen supply device, the anesthesia device is enlarged, and there is a possibility that oxygen bubbles may not reach the cage due to vibration of the aquarium during transport of raw fish. In this case, the amount of oxygen absorbed from the carp is reduced, and as with the former technique, the fish becomes drowned due to respiratory failure during transportation.

  In order to achieve the above object, the anesthesia method of the present invention includes an anesthesia step for dissolving a predetermined amount of carbon dioxide required for anesthesia of seafood in water, and an oxygen supersaturation step for maintaining dissolved oxygen in the water in a supersaturated state. It has.

  And by providing an anesthesia process that dissolves a predetermined amount of carbon dioxide required for anesthesia of seafood in water, it is possible to quickly anesthetize using simple equipment while maintaining good quality of seafood. it can. That is, since carbon dioxide contained in the atmosphere or living organism is used, foreign substances such as anesthetics do not remain in the fish and shellfish. Moreover, because carbon dioxide is easily dissolved in water, unlike low-temperature anesthesia, the concentration of dissolved carbon dioxide is reduced to a level that has an anesthetic effect with a simple device that simply vents carbon dioxide from a gas cylinder or the like into the water. Can be raised in time.

  Furthermore, by providing an oxygen supersaturation step for maintaining dissolved oxygen in water in a supersaturated state, a stable and long-term anesthesia can be performed using a compact and simple device. That is, since a large amount of dissolved oxygen exists in the water in the supersaturated state, a sufficient amount of oxygen is absorbed from the salmon to satisfy the individual oxygen demand, and the anesthetic limit time can be extended. In addition, since it is not necessary to bring oxygen bubbles into direct contact with the seafood salmon, it is possible to use a compact and simple device in which oxygen from a gas cylinder or the like is vented to any part of the water.

  In addition, when the dissolved oxygen in water when carbon dioxide reaches the predetermined amount is supersaturated, a large amount of dissolved oxygen exists in the water when seafood is anesthetized. The amount of oxygen absorbed is sufficient to meet the oxygen demand of each individual. As a result, it is possible to reliably prevent fish and shellfish from causing respiratory failure due to insufficient oxygen absorption immediately after anesthesia.

  Moreover, in the oxygen supersaturation step described above, the amount of dissolved oxygen in water is maintained at 12 mg / l or more in a predetermined appropriate water temperature range for each fish and shellfish.

  Here, the appropriate water temperature range is a water temperature range in which the daily activities of fish and shellfish are well maintained, and varies depending on the type of fish and shellfish. For example, it is 17-27 ° C. for Ishidai, 18-28 ° C. for yellowtail, and 10-28 ° C. for Suzuki. And even if it remove | deviates from any suitable water temperature range, the movement of seafood dulls and feeding behavior falls suddenly and weakens, or it falls into a temporary death state depending on the case.

In such an appropriate water temperature range, the amount of dissolved oxygen in water is 12 mg / l or more.
If the amount of dissolved oxygen is less than 12 mg / l, the oxygen concentration in the water is low and the amount of oxygen absorbed from the trough is insufficient, so that the individual oxygen demand cannot be satisfied sufficiently, and fish and shellfish have respiratory failure. Wake up and drown in a short time.

  Furthermore, the dissolved oxygen amount of 12 mg / l corresponds to the saturation solubility of oxygen at a water temperature of about 6 ° C., and the saturation solubility decreases as the temperature increases. Further, generally, the appropriate water temperature range for seafood is higher than the water temperature of 6 ° C. Therefore, in a proper water temperature range for fish and shellfish, it is always possible to maintain a supersaturated state by setting the dissolved oxygen amount to 12 mg / l or more.

  In addition, the first air diffuser for ejecting the carbon dioxide-containing gas from the pores and the second air diffuser for ejecting the oxygen-containing gas from the pores are provided separately in water, and the diameter of the pores is 2 μm or more and 100 μm or less. Set to.

  In the case where the first air diffuser for ejecting the carbon dioxide-containing gas from the pores and the second air diffuser for ejecting the oxygen-containing gas from the pores are provided separately and placed in water, the type and function of the gas, etc. Accordingly, pores having an appropriate size and shape can be selected. This makes it possible to freely adjust the size and amount of bubbles for each type of gas supplied, increase the dissolution rate of carbon dioxide, shorten the time required for anesthesia, and control the amount of dissolved oxygen with high accuracy. In addition, the efficiency of anesthesia work and the reduction of gas costs can be achieved.

Furthermore, the diameter of the pores is set to 2 μm or more and 100 μm or less.
When the diameter of the pores is less than 2 μm, the bubbles to be ejected are minute and the gas dissolution rate per unit volume increases, but the pores are clogged significantly. In particular, pores with a nano-level diameter require a high gas pressure, which increases piping costs, increases the frequency of inspections, and increases maintenance costs. On the other hand, if the pore diameter exceeds 100 μm, the required gas amount increases and the gas cost increases remarkably.

  The anesthesia method for seafood according to the present invention is such that while using a compact and simple device, the quality of the seafood is hardly deteriorated, and anesthesia is applied in a short time, and anesthesia can be stably maintained for a long time. Yes.

It is a perspective view which shows the whole structure of the anesthesia apparatus concerning this invention. It is a graph which shows the relationship between the anesthetic limit time and the amount of dissolved oxygen of a sea bream. It is a graph which shows the relationship between the anesthetic limit time of a yellowtail and the amount of dissolved oxygen. It is a graph which shows the relationship between the anesthetic limit time of Suzuki and the amount of dissolved oxygen. It is a graph which shows the relationship between a lower limit dissolved oxygen amount and water temperature.

  Hereinafter, embodiments of the present invention relating to an anesthesia method for fish and shellfish will be described with reference to the drawings to provide an understanding of the present invention. The direction indicated by the arrow F in FIG. 1 is the front, the direction indicated by the arrow L is the left, and the position and direction of each part described below are based on the front and the left.

First, the overall configuration of an anesthesia apparatus 1 to which the present invention is applied will be described with reference to FIG.
The anesthesia apparatus 1 includes a water tank 2 in which seawater 6 is injected and test fish 7 such as sea bream is accommodated, a pump apparatus 3 that purifies and circulates the seawater 6 in the water tank 2, and carbon dioxide gas in the seawater 6. And a bubble generating device 4 for jetting bubbles of oxygen gas and dissolving each gas in the seawater 6, and a gas concentration measuring device 5 for measuring the dissolved amount of carbon dioxide gas or oxygen gas in the seawater 6. The

  In the water tank 2, a rectangular thick plate-shaped base 8 is installed on the floor 11, and a box-shaped water tank body 9 made of a transparent member such as acrylic resin is placed and fixed on the base 8. Has been. And the upper part of this water tank main body 9 is open | released, the cover body 10 is covered, and the work body 10a and the work port 10b on either side for taking in / out the test fish 7 are opened in the cover body 10. As shown in FIG.

  Both the working port 10a and the working port 10b are covered with a rectangular cover 12 made of a transparent member such as an acrylic resin, and the peripheral corners of the cover 12 are both cut in a straight line so that the hypotenuse 12a is formed. Is formed. A gap 16a is opened between the oblique side 12a and the inner left corner 10a1 of the work port 10a, and between the oblique side 12a and the inner left corner 10a2 of the front of the working hole 10a, A gap 16b is opened, and a gap 16c is opened between the oblique side 12a and the inner right corner 10b1 of the rear portion of the work hole 10b.

  Thereby, the state of the test fish 7 in the seawater 6 accommodated in the aquarium 2 can be reliably visually recognized from the side of the aquarium main body 9 or from above the cover 12. Furthermore, carbon dioxide gas and oxygen gas that have not been dissolved in the seawater 6 are exhausted to the outside through the gaps 16a, 16b, and 16c described above, and a water supply tube 14 and a suction tube 15 described later are placed in the water tank 2. Can be easily inserted into the seawater 6.

  Further, in the pump device 3, the water flow pump 13 is disposed on the floor surface 11, the discharge port 13 a of the water flow pump 13 is connected to one end of the water supply tube 14, and the other end of the water supply tube 14 has a gap 16 a. It is inserted into the seawater 6 through. Similarly, the water inlet 13b of the water flow pump 13 is connected to one end of the suction tube 15, and the other end of the suction tube 15 is inserted into the seawater 6 through the gap 16c.

  Accordingly, when the water flow pump 13 is driven, the seawater 6 in the water tank 2 is sucked up from the suction tube 15, and impurities are filtered by a filter incorporated in the water flow pump 13, and then passed through the water supply tube 14 and the water tank 2. The seawater 6 is circulated by repeating this operation, and the water quality is maintained well.

  In the bubble generating device 4, the carbon dioxide gas cylinder 17 and the oxygen gas cylinder 18 are erected on the floor 11 in order from the rear, and the gas pressure is adjusted above the carbon dioxide gas cylinder 17 and the oxygen gas cylinder 18, respectively. Regulator 19 and regulator 20 are mounted.

  Here, on the bottom surface 9a of the water tank main body 9 described above, a cylindrical first air diffuser 23 and a second air diffuser 24 are arranged in parallel from the rear with the longitudinal direction turned to the left and right. Of these, the first air diffuser 23 is communicated with a cylindrical main pipe portion 23a whose left end is closed and a large number of pores 23a1 are formed in the outer periphery in the radial direction, and a right end of the main pipe portion 23a. It is comprised from the injection tube part 23b extended in radial direction. Similarly, the second air diffuser 24 is also connected to the cylindrical main pipe portion 24a whose left end is closed and a large number of pores 24a1 are radially drilled on the outer periphery, and to the right end of the main pipe portion 24a. And an injection tube portion 24b extending in the direction.

  Of these, the injection tube portion 23b and the injection tube portion 24b are connected to communicate with the discharge tube 19a of the regulator 19 and the discharge tube 20a of the regulator 20 through the gas tube 21 and the gas tube 22, respectively. .

  As a result, carbon dioxide gas adjusted to an appropriate discharge pressure using the regulator 19 is injected into the first air diffuser 23 via the gas tube 21 and ejected as bubbles from a number of fine pores 23a1. it can. Similarly, oxygen gas adjusted to an appropriate discharge pressure using the regulator 20 can be injected into the second air diffuser tube 24 via the gas tube 22 and ejected as bubbles from a number of fine pores 24a1. .

  Further, in the gas concentration measuring device 5 described above, a measuring table 28 is disposed on the left side of the water tank 2, and a measuring stand 27 is installed on the measuring table 28. The measuring stand 27 has a rectangular plate-shaped base 27a, a guide bar 27b erected from the water tank 2 side on the base 27a, and one end of the guide bar 27b whose height can be adjusted and horizontally rotated. The gripping stay 27c is externally fitted.

  The other end of the gripping stay 27c protrudes toward the water tank 2, and a columnar sensor body 26b of the carbon dioxide gas concentration meter 26 is suspended from the tip thereof, and the sensor part 26b1 at the lower end of the sensor body 26b is It is immersed in the seawater 6 through the gap 16b described above. And the upper end of the sensor body 26b is connected to the measurement main body 26a for carbon dioxide provided with the calculation part and the display part and mounted on the base 27a via the cable 26c.

  Thus, when the concentration signal from the sensor unit 26b1 immersed in the seawater 6 is input to the measurement main body 26a via the cable 26c, the concentration of carbon dioxide gas is sequentially calculated and displayed immediately. I have to.

  Further, in the water tank 2, the columnar sensor body 25 b of the oxygen gas concentration meter 25 having the sensor portion 25 b 1 at the lower end is immersed in the seawater 6 in the vicinity of the sensor body 26 b described above. One end of a cable 25c is connected to the upper end of the sensor body 25b, and the other end of the cable 25c passes through the same gap 16b as that of the sensor body 26b described above and is for oxygen gas placed on the measurement table 28. Connected to the measurement main body 25a.

  Thus, when the concentration signal from the sensor unit 25b1 immersed in the seawater 6 is input to the measurement main body 25a via the cable 25c, the oxygen gas concentration is sequentially calculated and displayed immediately. ing.

  Next, an anesthesia process and an oxygen supersaturation process by the anesthesia apparatus 1 having such a configuration will be described. However, the present invention is not limited to such examples.

  In the anesthesia process, anesthesia with carbon dioxide was performed on the test fish 7 such as sea bream, yellowtail, and sea bass at a water temperature within the appropriate water temperature range and a water temperature outside the appropriate water temperature range for each type.

  Specifically, using an electric heater, dry ice, etc., the seawater 6 is set to 15-30 ° C. for sea bream, 15-30 ° C. for yellowtail, and 5-30 ° C. for Suzuki, and then the water tank 2 cover. The test fish 7 captured from the ginger with a ball net or the like is thrown into the aquarium 2 through the work ports 10a and 10b which are opened by removing 12.

  Then, after setting the discharge pressure of the carbon dioxide gas from the carbon dioxide gas cylinder 17 to 0.5 MPa using the regulator 19, the carbon dioxide gas is supplied from the carbon dioxide gas cylinder 17 through the gas tube 21 to the first air diffuser. 23, when carbon dioxide gas is injected into the seawater 6 from the pores 23a1 provided in the main pipe portion 23a of the first air diffusion pipe 23, the carbon dioxide gas is jetted into the seawater 6 and dissolved. The dissolved carbon dioxide increases to a predetermined concentration.

  When the test fish 7 rolls over in such a state in which carbon dioxide is dissolved, it is determined that the test fish 7 has been anesthetized, and the supply of carbon dioxide gas by the regulator 19 is stopped. At this time, dissolved oxygen in water is in a supersaturated state by an oxygen supersaturation step described in detail below.

  Further, in the oxygen supersaturation step, as described above, in parallel with the injection of the carbon dioxide gas from the carbon dioxide gas cylinder 17 into the first air diffuser 23, the oxygen gas whose discharge pressure is adjusted using the regulator 20 is converted into the oxygen cylinder. 18 is injected into the second air diffuser 24 through the gas tube 22.

  Then, oxygen gas is ejected into the seawater 6 from the pores 24a1 provided in the main pipe portion 24a of the second air diffuser 24, and dissolved into the seawater 6 to dissolve dissolved oxygen in the seawater 6. It is maintained up to a predetermined concentration.

  At this time, the dissolved oxygen amount DO is set between about 8 mg / l and about 15 mg / l by changing the discharge pressure by the regulator 20 and changing the form and amount of bubbles blown out from the pores 24a1. Furthermore, the dissolved oxygen amount DO is set to about 5 mg / l by performing so-called aeration in which outside air is blown into the seawater 6 by an air pump (not shown).

  And when this dissolved oxygen amount DO is higher than the saturation solubility of oxygen at the same pressure and the same water temperature, the dissolved oxygen is in a supersaturated state and excess oxygen exists in the water. For example, the saturation solubility of oxygen at 25 ° C. is 8.11 mg / l, but as shown in the investigation described later, when the dissolved oxygen amount DO is 12.1 mg / l at 25 ° C., the dissolved oxygen is in a supersaturated state. Thus, a sufficient amount of oxygen can be supplied to the salmon of the test fish 7.

  Next, the influence of the above-described anesthesia process and oxygen supersaturation process on the anesthetic limit time will be investigated, and the results of the investigation will be described with reference to FIGS.

[Ishidai]
In Ishidai, carbon dioxide gas and oxygen gas are jetted into water as bubbles at water temperatures of 15 ° C, 20 ° C, 25 ° C, and 30 ° C. The dissolved oxygen amount DO was changed from about 5 mg / l to about 15 mg / l by gas, and the anesthetic limit time at that time was measured.

  Here, as described above, the anesthesia limit time is an elapsed time from when the anesthesia is applied until the fish is drowned. From 3 hours to 12 hours after the passage of time, the fish is exercised and the activity state is observed, and the case where it is recognized that the fish is breathing spontaneously is determined as “survival”, When the spontaneous movement of the fish disappeared and it no longer responded to external stimuli, it was determined as “dead”, and the elapsed time until this “dead” was determined as the anesthetic limit time.

  In addition, although the measurement of the anesthesia elapsed time in each dissolved oxygen amount DO is set to 12 hours, this means that if the fish is “alive” even if 12 hours have elapsed, it will continue to survive even if a longer time elapses. This is because it is known.

  Table 1 shows the investigation results of the limit time for anesthesia in the sea bream.

  According to Table 1 and FIG. 2, when the water temperature is 15 ° C. and 30 ° C., the maximum anesthetic time is as short as 1.3 hours at all dissolved oxygen amounts DO, which is much shorter than the required 5 hours of anesthesia time.

  On the other hand, when the water temperature is 20 ° C. and 25 ° C. and the appropriate water temperature range of the sea bream is 17 to 27 ° C., when the dissolved oxygen amount DO is about 11 mg / l or more or about 12 mg / l or more, Ishidai can maintain the survival state even when 12 hours have passed since the oxygen became highly supersaturated.

  At this time, even if the water temperature is within a suitable water temperature range of 17 to 27 ° C., the dissolved oxygen amount DO is as small as about 5 mg / l or about 8 mg / l as in the conventional case, and the oxygen in the seawater is unsaturated. Then, the maximum anesthesia limit time is as short as 0.8 hours

[Buri]
Also in yellowtail, carbon dioxide gas and oxygen gas are jetted into water as bubbles at each water temperature of 15 ° C., 20 ° C., 25 ° C., and 30 ° C., and the yellowtail is anesthetized with carbon dioxide gas. In addition, the amount of dissolved oxygen DO was changed from about 5 mg / l to about 15 mg / l by outside air or oxygen gas, and the anesthetic limit time at that time was measured.

  Table 2 shows the survey results of the anesthetic limit time in yellowtail.

  According to Table 2 and FIG. 3, when the water temperature is 15 ° C. and 30 ° C., the maximum anesthetic limit time is as short as 1.2 hours at all dissolved oxygen amounts DO, which is much shorter than the required anesthetic time of 5 hours.

  On the other hand, when the water temperature is 20 ° C. and 25 ° C. and the suitable water temperature range of the yellowtail is 18 to 28 ° C., when the dissolved oxygen amount DO is about 11 mg / l or more or about 12 mg / l or more, Oxygen is in a highly supersaturated state, and yellowtail can remain alive even after 12 hours have passed since anesthesia.

  Even in this case, even if the water temperature is within a suitable water temperature range of 18 to 28 ° C., the dissolved oxygen amount DO is as low as about 5 mg / l or about 8 mg / l as in the conventional case, and oxygen in seawater is not saturated. In the state, the anesthesia limit time is as short as 0.5 hours at the longest.

[Suzuki]
In Suzuki, at each water temperature of 5 ° C., 10 ° C., 15 ° C., 20 ° C., 25 ° C., and 30 ° C., carbon dioxide gas and oxygen gas are blown into water as bubbles, and carbon dioxide gas among them Suzuki was anesthetized and the amount of dissolved oxygen DO was changed from about 5 mg / l to about 15 mg / l by outside air or oxygen gas, and the anesthetic time limit was measured.

  Table 3 shows the survey results of the limit time for anesthesia in Suzuki.

  According to Table 3 and FIG. 4, when the water temperature is 5 ° C. and 30 ° C., the maximum anesthesia time is as short as 1.3 hours at all dissolved oxygen amounts DO, which is much shorter than the required anesthesia time of 5 hours.

  On the other hand, when the water temperature is 10 ° C., 15 ° C., 20 ° C., 25 ° C. and the appropriate water temperature range of Suzuki is 10 to 28 ° C., the dissolved oxygen amount DO is about 11 mg / l or more or about 12 mg / l or more. Then, the oxygen in the seawater becomes highly supersaturated, and even if 12 hours have passed since anesthesia, Suzuki can maintain its survival state.

  Even in this case, even if the water temperature is within a suitable water temperature range of 10 to 28 ° C., the dissolved oxygen amount DO is as low as about 5 mg / l, about 8 mg / l, or about 10 mg / l as in the past, When the oxygen of the water is not saturated, the anesthetic limit time is a short 1.1 hours at the longest.

A summary of the above survey results is shown in FIG.
According to this, the lower limit dissolved oxygen amount DOmin, which is the minimum amount of dissolved oxygen necessary for observing the anesthetic limit time of 12 hours or more, is different in the appropriate water temperature range even if the fish type is different and the appropriate water temperature range is changed. It can be seen that it is 11 mg / l or 12 mg / l.

  Therefore, in order to enable anesthesia limit time of 12 hours or more in the entire range of each appropriate water temperature range, the dissolved oxygen amount DO is set to 12 mg / l or more (the range in which long-term anesthesia is indicated by the hatched portion in FIG. 5). It can be seen that it should be held. This result was the same in other seafood.

  As described above, the method for anesthesia of seafood to which the present invention is applied, while using a compact and simple device, hardly deteriorates the quality of seafood, anesthetizes in a short time, and stabilizes anesthesia for a long time. Sustainable.

23 1st air diffuser 23a1 pore 24 2nd air diffuser 24a1 pore

Claims (4)

An anesthesia process in which a predetermined amount of carbon dioxide required for anesthesia of seafood is dissolved in water;
An anesthesia method for seafood comprising an oxygen supersaturation step for maintaining dissolved oxygen in water in a supersaturated state. The method for anesthetizing fish and shellfish according to claim 1, wherein dissolved oxygen in water when carbon dioxide reaches the predetermined amount is supersaturated. In the oxygen supersaturation step,
The method for anesthetizing fish and shellfish according to claim 1 or 2, wherein the amount of dissolved oxygen in water is maintained at 12 mg / l or more in a predetermined appropriate water temperature range for each fish and shellfish. A first air diffuser for ejecting carbon dioxide-containing gas from the pores and a second air diffuser for ejecting oxygen-containing gas from the pores are provided separately and disposed in the water,
The method for anesthetizing fish and shellfish according to claim 1, wherein the diameter of the pores is set to 2 μm or more and 100 μm or less.

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