JP5438194B2 - How to raise, store or transport tuna underage fish - Google Patents

Description

The present invention relates to a method for breeding, storing or transporting tuna immature fish .

  Conventionally, tuna farming has been carried out from the viewpoint of storage of tuna resources and stable supply of tuna to consumers. In general, tuna aquaculture is grown to a size that can be shipped to the market in a ginger installed on the surface of a natural juvenile (commonly known as Yokowa) about 13 weeks old (with a body length of about 200-300 mm) captured in the sea. Has been done. In recent years, so-called on-shore aquaculture has also been attempted in which captured natural juveniles are grown to a size that can be shipped to the market within a ginger installed on land.

  When tuna is raised in a breeding tank set up on land, artificial water is used for tuna breeding by mixing natural seawater taken directly from the sea or fresh water with ingredients equivalent to those contained in natural seawater. Artificial seawater generated in 1 is used. In this case, the salinity of the breeding water is generally considered to be a narrow-salt seawater fish since the tuna is an open-sea fish. It has been adjusted. Here, the narrow salinity means that the range of the salinity environment that can be handled by fish is narrow, and it means that it is difficult to survive unless it is substantially the same salinity environment as the inhabited salt environment. In addition, the nature of fish with a wide range of salinity environment that can be handled against narrow salinity is called broad saltiness, and fish that live mainly in brackish waters fall under this category.

  However, in the tuna breeding process on land, it is economical to maintain the salinity of the breeding water at around 34 psu regardless of whether natural seawater or artificial seawater is used for breeding water. There is a problem that the labor burden is large. Specifically, when natural seawater is used for breeding water, the economic and labor burden for intake and transportation of natural seawater is large. Moreover, when artificial seawater is used for breeding water, the economic burden with respect to the artificial seawater preparation agent required for preparation of artificial seawater, and the labor burden with respect to adjustment of artificial seawater are large. Furthermore, the salinity of the breeding water in which tuna swims must be constantly monitored to maintain the salinity at approximately 34 psu, which has a problem in that the economic and labor burden is large. In addition, since the prior art which concerns on this application is not related to literature public knowledge, there is no prior art literature information which should be described.

The present invention has been made to address the above problems, and its object is rearing immature tuna, storage or economic and breeding immature tuna labor burden can be reduced in the transport, storage or transportation method Is to provide.

In order to achieve the above object, a feature of the present invention is a method for breeding, storing or transporting an adult tuna fish in a swimming tank, wherein the swimming tank is filled with breeding water having a salinity of 15 psu or more and less than 30 psu. , look including the step of introducing the tuna immature the swimming bath, when introducing the immature tuna swimming bath is to the water surface of swimming tank uniform illuminance.

  In this case, in the method for breeding, storing or transporting the tuna immature fish, the tuna immature fish can be bred, stored or transported by the breeding water having a salt content of 15 psu or more and 25 psu or less.

  According to the characteristics of the present invention configured as described above, the tuna immature fish is reared, stored or transported by the rearing water having a salinity of about 15 psu or more and 30 psu or less. As a result, according to experiments and breeding observations by the present inventors, it was confirmed that natural juveniles of about 13 weeks after birth (with a body length of about 200 to 300 mm) were raised at a survival rate of about 50% or more for 28 weeks or more. did. That is, it was confirmed that tuna, which was conventionally considered to be narrow-salt, can be reared in a salt environment at a maximum of 19 psu lower than the salt content of the original habitat. Thereby, when natural seawater is used for breeding water, the amount of natural seawater intake (amount of use) can be reduced, thereby reducing the economic and labor burden on water intake and transportation. In addition, when artificial seawater is used for breeding water, the amount of artificial seawater conditioning agent necessary for the preparation of artificial seawater can be reduced and the range of salt content in artificial seawater is widened. It is possible to reduce the economic burden on the artificial seawater adjusting agent necessary for the production and the labor burden on the adjustment of the artificial seawater. In addition, the range of salinity in which the tuna immature fish can survive increases, thereby reducing the economic and labor burden of monitoring the salinity of the breeding water in which the tuna immature fish swim. As a result, economic and labor burdens can be reduced in the breeding, storage or transportation of tuna underage fish.

  The above-mentioned “about 13 weeks after birth” is estimated from the captured natural juvenile's body length, weight or tuna capture date and generally known tuna spawning season. This is because the exact date of hatching of tuna natural larvae caught in the natural seas is actually unknown. In addition, artificial seawater preparations are for breeding water equivalent to natural seawater, specifically, for adjusting breeding water that has the same composition as natural seawater and the ratio and concentration of each component is equivalent to natural seawater. A powdery or liquid substance prepared by artificially preparing various components contained in natural seawater.

Further, the present invention relates to the method for breeding, storing or transporting the tuna immature fish, wherein the breeding water is seawater, fresh water, ground water having a salinity of about 15 psu or more, or adjusting the salinity in the ground hot spring water having the salinity of about 15 psu or more. Can be configured. This can reduce the economic and labor burden in raising tuna underage fish. In addition, in the method for breeding, storing or transporting the tuna immature fish, when the tuna immature fish is transferred to a salt environment of 20 pus or less, the salinity of the breeding water can be gradually lowered. In addition, the present invention provides a method for breeding, storing or transporting a tuna immature fish, wherein the tuna immature fish is bred in a salinity environment of 25 psu or more and less than 30 psu, and the salinity is adjusted to 15 psu or more and 25 psu or less. bred immature tuna can be stored or transported. According to these, tuna can be transferred to a low salinity environment more safely. The present invention also breeding immature of the tuna, in storage or transportation method, breeding immature tuna by breeding water adjusted salinity than 17Psu, can be stored or transported. The present invention also breeding immature of the tuna, in storage or transportation method, breeding immature tuna by breeding water adjusted to salinity in 20psu ± 3psu, can be stored or transported. According to these, tuna can be bred efficiently while reducing the economic and labor burden on breeding water.

  In these cases, groundwater or underground hot spring water having a salinity of about 15 psu or more can be used as breeding water in the method for breeding, storing or transporting the tuna underage fish. According to this, groundwater or underground hot spring water with a salinity of about 15 psu or more is used for rearing, storage or transportation of tuna underage fish. The fresh water or the like can be mixed with the ground water or the underground hot spring water to reduce the salinity to a range of about 15 psu or more, and can be used as breeding water for tuna immature fish. Thereby, breeding water can be prepared more cheaply and easily, and economical and labor burdens can be reduced in breeding, storage or transportation of tuna underage fish.

The present invention can be implemented not only as a method for breeding, storing or transporting tuna , but also as an invention for breeding water for breeding, storing or transporting tuna.

It is a block diagram which shows typically the structure of the principal part of the tuna breeding equipment used for the tuna breeding method which concerns on one Embodiment of this invention. (A) is a breeding experiment result graph showing the change in salinity of breeding water with respect to the number of breeding weeks in the first year, and (B) shows the change in survival rate with respect to the number of breeding weeks in the first year. It is a rearing experiment result graph. (A) is a breeding experiment result graph showing the change in salinity of breeding water with respect to the number of breeding weeks in the second year, and (B) shows the change in survival rate with respect to the number of breeding weeks in the second year. It is a rearing experiment result graph.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of a tuna breeding, storage or transportation method and breeding water for tuna breeding, storage or transportation according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing a configuration of a main part of a breeding facility used for tuna breeding by a tuna breeding method according to the present invention. Note that each drawing referred to in the present specification is schematically represented by exaggerating some of the components in order to facilitate understanding of the present invention. For this reason, the dimension, ratio, etc. between each component may differ.

  This tuna breeding facility includes a swimming tank 10. The swimming tank 10 is a water tank for raising tuna, and is configured by stretching a sheet material in a bottomed cylindrical shape with the upper part opened. In the present embodiment, the swimming tank 10 has a diameter of 5 m and a depth of 1.5 m, and the swimming tank 10 is filled with breeding water at a depth of about 1 m. A cylindrical intake pipe 11 is erected at the center of the swimming tank 10. The intake pipe 11 is a tube for taking the breeding water in the swimming tank 10 to keep the water level in the swimming tank 10 constant and guiding the taken breeding water to the drain pit 12. Therefore, a region where the tuna can swim in the swimming tank 10 is a ring-shaped space portion between the inner wall of the swimming tank 10 and the intake pipe 11.

  The drainage pit 12 guides a part of the breeding water led from the swimming tank 10 to the drainage pipe 13 and another part of the breeding water taken to guide the other part to the pressure filtration device 15 via the pumping pump 14. It is a container for temporary storage. The pumping water pump 14 is a liquid feeding pump for pumping the breeding water stored in the drainage pit 12 and supplying it to the pressure filtration device 15. The pressure filtration device 15 is a device that introduces breeding water into a sealed container containing a filtering material that filters out foreign substances, and filters the breeding water based on a pressure difference between the breeding water introduction side and the discharge side. A UV sterilizer 16 is connected to the pressure filtration device 15. The UV sterilization device 16 is a device for preventing the propagation of bacteria by killing microorganisms existing in the breeding water by irradiating the breeding water with UV (ultraviolet rays). A biological filtration tank 17 is connected to the UV sterilizer 16.

  The biological filtration tank 17 is a water tank for supplying the purified breeding water to the swimming tank 10 after decomposing and purifying organic matter in the breeding water using bacteria. In addition to the UV sterilizer 16, a water supply pipe 18 and an underground seawater water supply facility 20 are connected to the biological filtration tank 17. The water supply pipe 18 is a pipe for supplying fresh water (fresh water) to the biological filtration tank 17, and is connected to the water supply via a manual valve 18a on the upstream side of the pipe. The underground seawater water supply facility 20 is a group of facilities that pumps seawater existing underground through a water intake pipe 21 driven into the ground by a pumping pump 22. In the present embodiment, seawater existing in the basement, so-called underground seawater, is pumped up through the intake pipe 21 driven to about 20 m underground. In addition, although there is generally no clear definition, "groundwater" is groundwater containing salt water equivalent to brackish water or seawater in this embodiment.

  Above the swimming tank 10, four lighting fixtures 19 (only three are shown) are provided via support members (not shown). The illuminator 19 is an illuminating device for illuminating the inside of the swimming tank 10, and is configured by a projector that can irradiate light with uniform illuminance over a wide range, and the water surface of the swimming tank 10 with substantially uniform illuminance. In order to illuminate, it is arranged substantially evenly along the circumferential direction of the swimming tank 10. In this case, the “substantially uniform illuminance” is such a degree of uniformity that a bright part and a dark part cannot be confirmed by human eyes. These illuminators 19 are connected to an illuminance control device (not shown). The illuminance control device is a control device that can continuously change the illuminance of the illuminator 19 within a range from 0 lx (lx: lux) to 500 lx in accordance with a set value by the operator.

  In addition, the swimming tank 10 is generally necessary for raising fish such as aeration equipment (not shown) for supplying oxygen to the breeding water in the swimming tank 10 and the biological filtration tank 17. The facilities are equipped. However, since these facilities are not directly related to the present invention, description thereof is omitted. The swimming tank 10 and the illuminating device 19 configured in this way are installed in a building (not shown) that can block incident light from outside (mainly artificial light) at night and incorporate natural light during the day. Has been. That is, the tuna breeding in this embodiment is performed in the swimming tank 10 installed on land.

  Next, a method for raising tuna using the tuna breeding equipment configured as described above will be described. First, a breeder who raises tuna fills the swimming tank 10 with breeding water of a predetermined salt before putting the tuna into the swimming tank 10. Specifically, the breeder operates the pumping water pump 22 to pump up groundwater from the ground and introduces it into the biological filtration tank 17. The underground seawater introduced into the biological filtration tank 17 is introduced into the swimming tank 10 after filling the biological filtration tank 17. Then, the breeder starts the circulation of the breeding water by starting the operation of the pumping water pump 14, the pressure filtration device 15, and the UV sterilization device 16, and turns on the lighting device 19 to turn the water surface of the swimming tank 10 on. Illuminate with approximately uniform illumination. In this case, since the underground seawater is generally sterile, it may be configured to be directly introduced into the swimming tank 10 without using the biological filtration tank 17.

  Next, the breeder prepares the breeding water in the swimming tank 10. Specifically, after measuring the salinity of the breeding water introduced into the swimming tank 10, the breeder adjusts the salinity of the breeding water within a range of about 25 psu or more and less than 30 psu according to the measurement result. That is, if the salinity of the breeding water introduced into the swimming tank 10 is less than 25 psu, the breeder puts the artificial seawater preparation agent for preparing artificial seawater into the swimming tank 10 to obtain the salinity of the breeding water. Increase to about 25 psu or more and less than 30 psu. If the salinity of the breeding water introduced into the swimming tank 10 exceeds 30 psu, the breeder opens the manual valve 18a and introduces fresh water into the swimming tank 10 to reduce the salinity of the breeding water. Reduce to 25 psu or more and less than 30 psu.

  In this case, it is naturally possible to breed tuna even if the salinity of the breeding water exceeds 30 psu. Therefore, when the salinity of the breeding water introduced into the swimming tank 10 exceeds 30 psu, the salinity breeding water may be used as it is without adjusting the salinity. However, in this case, in the present embodiment, in order to reduce the salinity of the breeding water in the process described later, it is desirable to adjust it to about 30 psu at the highest. On the other hand, if the salinity of the groundwater pumped from the basement is already about 25 psu or more and less than 30 psu, it is not necessary to adjust the salinity of the breeding water. Thereby, when the salinity of the groundwater taken from underground is about 25 psu or more and less than 30 psu, the economical and labor burden for adjusting the salinity of the breeding water is reduced. In addition, since the range for adjusting the salinity is as wide as about 25 psu or more and less than 30 psu, the economical and labor burden for preparing the salinity of the breeding water is reduced.

  Next, the breeder prepares tuna to be raised in the swimming tank 10. In this case, in this embodiment, the breeder is a tuna immature fish (larvae or larvae) after about 13 weeks after birth (the body length (tail fork length) is about 200 mm or more) and until it has fertility. Prepare young fish. Specifically, the breeder releases a natural juvenile (commonly known as Yokowa) about 13 weeks old, captured in the near sea, into the swimming tank 10. In this case, it is preferable that the breeder moves the immature fish of the tuna captured in the sea for a while with a ginger once set on the sea surface, and then moves it to the swimming tank 10. Thereby, it can be expected to disperse the stress applied to the tuna immature fish and suppress the subsequent decrease in the survival rate. In the case of natural larvae, the exact date of egg laying or hatching is unknown. Therefore, “about 13 weeks after birth” is, as described above, estimated from the body length, weight or tuna capture date of the captured natural juvenile and the generally known tuna spawning season. .

  Next, the breeder adjusts the salinity of the breeding water in the swimming tank 10 to a range of 20 psu ± 3 psu after accustoming the tuna to the environment in the swimming tank 10 for about 1 to 3 days. Specifically, the breeder lowers the salinity of the breeding water in the swimming tank 10 to a range of 20 psu ± 3 psu by opening the manual valve 18 a and adding fresh water to the biological filtration tank 17. In this case, the breeder reduces the salinity of the breeding water at a rate of about 5 psu in about 20 hours. Thereby, the salinity of breeding water can be reduced, suppressing the burden to a tuna. Further, when the breeder lowers the salinity of the breeding water to less than 17 psu, the breeder adjusts the fresh water so that the salinity of the breeding water falls within a range of 20 psu ± 3 psu by adding a groundwater or artificial seawater preparation. Thereby, the salinity of the breeding water in the swimming tank 10 is adjusted to the range of 20 psu ± 3 psu. And the breeder measures the salinity of the breeding water regularly (for example, once a day) and adjusts the salinity of the breeding water to the range of 20 psu ± 3 psu to a size that allows the tuna to be shipped to the market. Raise.

(Experiment contents and results)
Next, the experiment conducted by the present inventors and the result will be described. In order to clarify the influence of breeding water on the survival rate of tuna whose salinity is lower than that of natural seawater, the present inventors examined the change in survival rate when the salinity of the breeding water in the swimming tank 10 was reduced. Examined.

  Specifically, the present inventors prepared four swimming tanks 10 shown in FIG. 1 that were filled with lower salt water than natural seawater, and each swimming tank 10 had approximately the same number of tuna (about 13 weeks old). Feeding experiments were conducted twice a year in total at a rate of once a year. In this breeding experiment, tuna was bred in the range of about 24 to 27 psu of salinity in the first year, and tuna was bred in the range of about 17 to 25 psu in the second year. The results of these breeding experiments are shown in FIGS. 2 (A), (B) and FIGS. 3 (A), (B), respectively. In each of these figures, (A) shows the change in salinity of the breeding water with respect to the number of breeding weeks, and (B) shows the change in survival rate with respect to the number of breeding weeks. And in each figure, the circle mark, the triangle mark, the square mark, and the cross mark show each four swimming tanks 10. Moreover, the salinity of breeding water is shown by rounding off the average salinity for one week rounded off the decimal point.

  In the breeding experiment in the first year, the swimming tank 10 was a tuna startling action (a panic phenomenon in which the tuna was surprised by a sudden environmental change (mainly a sudden change in light) and became excited and furiously swimming). The survival rate decreased to about 20-30% from the start of breeding to the 23rd week due to the collision with the inner wall of the fish and the jump out of the swimming tank 10. However, in the results of the breeding experiment in the first year, as shown in FIGS. 2 (A) and (B), no correlation was found between the change in salinity and the change in survival rate in the breeding water. . That is, the amount of food intake and survival rate did not change abruptly even at the 9th to 10th weeks and the 14th to 16th weeks when the salinity of the breeding water was 25 psu or less. On the other hand, in the 4th to 6th weeks and the 19th to 12th weeks when the salinity of the breeding water became 27 psu, the amount of food intake and the survival rate did not change suddenly. From these, it is considered that tuna can be reared in a salinity environment of at least 25 psu if attention is paid only to the salinity environment.

  In the second year's breeding experiment, by taking measures to prevent the startling behavior of tuna, by suppressing the occurrence of startling behavior of tuna, the survival rate was reduced to about 50 from the start of breeding to the 23rd week. It could be maintained at ˜60%. And also in this 2nd year breeding experiment result, as shown to FIG. 3 (A) and (B), a correlation was not found between the change of the salinity in breeding water, and the change of survival rate. . That is, even in the 9th to 26th weeks when the salinity of the breeding water became 20 psu or less, the amount of food intake and the survival rate did not change suddenly. In particular, the amount of food intake and survival rate did not change suddenly even during the 20th to 21st weeks when the salinity of the breeding water was about 17 psu. Thereby, it is considered that tuna can be reared in a salt environment of at least 17 psu if attention is paid only to the salt environment.

  Furthermore, in this second year breeding experiment, the present inventors observed the state of tuna by reducing the salinity of the breeding water to about 15 psu temporarily (about 24 hours) at the 21st week. However, even in this case, there was no change in tuna intake or swimming state. Therefore, it is considered that tuna can be reared even in a salt environment of about 15 psu, focusing only on the salt environment.

  As can be understood from the above operation explanation and experimental results, according to the above embodiment, the tuna is bred with breeding water having a salinity of 20 psu ± 3 psu. As a result, according to experiments and breeding observations by the present inventors, it was confirmed that natural juveniles of about 13 weeks after birth (with a body length of about 200 to 300 mm) were raised at a survival rate of about 50% or more for 28 weeks or more. did. That is, it was confirmed that tuna, which was conventionally considered to be narrow-salt, can be raised in a salt environment at a maximum of 19 psu lower than the salt content of the original habitat (about 34 psu). Thereby, when natural seawater is used for breeding water, the amount of natural seawater intake (amount of use) can be reduced, thereby reducing the economic and labor burden on water intake and transportation. In addition, when artificial seawater is used for breeding water, the amount of artificial seawater conditioning agent necessary for the preparation of artificial seawater can be reduced and the range of salt content in artificial seawater is widened. It is possible to reduce the economic burden on the artificial seawater adjusting agent necessary for the production and the labor burden on the adjustment of the artificial seawater. Furthermore, since the salinity range in which tuna can survive is expanded, the economic and labor burden for monitoring the salinity of breeding water in which tuna swims is reduced. As a result, economic and labor burdens can be reduced in the breeding, storage or transportation of tuna.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, in the above embodiment, the salinity of the breeding water is adjusted to 20 psu ± 3 psu. However, according to the breeding experiments and breeding observations by the present inventors, it is considered that breeding is possible even with 15 psu of salt water as described above. Therefore, the salinity of the breeding water is not necessarily limited to the above embodiment as long as it is appropriately set within the range of about 15 psu or more and about 30 psu or less. That is, the salinity of the breeding water may be appropriately set in the range of about 15 psu or more and about 30 psu or less in consideration of the economic burden and labor burden for the preparation of the salinity of the breeding water. Also by this, the same effect as the above embodiment can be expected.

  Moreover, in the said embodiment, breeding water was prepared using underground seawater. However, breeding water does not necessarily have to be prepared using groundwater if the salinity is adjusted in the range of about 15 psu or more and about 30 psu or less. That is, breeding water may be prepared by adding fresh water to natural seawater, or an artificial seawater preparation may be added to fresh water. In addition, underground hot spring water can be used instead of or in addition to underground seawater or artificial seawater. Hot springs generally refer to groundwater at 25 ° C or higher, but some hot springs have a salinity comparable to brackish water or seawater. For this reason, by using hot spring water having a salinity comparable to that of brackish water or seawater, breeding water having a salt content and temperature suitable for tuna breeding can be prepared. The use of hot spring water is extremely effective especially when tuna is cultivated on land in mountainous areas where it is difficult to procure natural seawater, or when the breeding water needs to be heated in winter. Thereby, economical and labor burden can be reduced in the breeding of tuna.

  In the above embodiment, when reducing the salinity of the breeding water prepared in the range of about 25 psu or more and less than 30 psu to 20 psu ± 3 psu, the salinity of the breeding water is reduced at a rate of about 5 psu in about 20 hours. I let you. However, the rate of reducing the salt content is appropriately determined according to the tuna's age, age, or health condition, and is not limited to the above embodiment. According to the breeding experiments and breeding observations of the present inventors, the tuna was not weakened or died even when the tuna raised in the breeding water having a salinity of 34 psu was directly transferred to the breeding water having a salinity of 25 psu. Further, even when the salinity of the breeding water in which tuna swims was lowered from 34 psu to 20 psu over 24 hours, the tuna was not weakened or died. For this reason, when the salinity is 25 psu or more, it is considered that tuna may be directly transferred to different salinity environments. On the other hand, when tuna is transferred to a salinity environment having a salinity of 20 psu or less, it is considered that the tuna can be transferred more safely by gradually getting used to the salinity environment of 20 psu or less over a certain period of time. .

  Moreover, in the said embodiment, the swimming tank 10 was installed in the building which can take in natural light. However, it is a matter of course that the swimming tank 10 may be installed outdoors. Tuna breeding is not limited to breeding in the swimming tank 10, but may be so-called sea surface culture in a sea area where the salinity is about 15 psu or more and about 30 psu or less. Also by these, the same effect as the above-mentioned embodiment can be expected.

  In addition, breeding tuna with breeding water having a salinity in the range of about 15 psu or more and about 30 psu or less reduces the physical burden of tuna for adjusting osmotic pressure. In addition, breeding tuna with breeding water having a salinity of about 15 psu or more and about 30 psu or less can also be expected to have an insecticidal effect on parasites existing in the breeding water having the same salinity as natural seawater. That is, the present invention in which tuna is bred with breeding water having a salinity of about 15 psu or more and about 30 psu or less can also be implemented as a tuna physical strength recovery method or a disease healing promotion method.

  Moreover, in the said embodiment, the example which applied this invention to the breeding of a tuna was demonstrated. However, the present invention can be applied when tuna is stored or transported. Also by this, the same effect as the above-mentioned embodiment can be expected.

  Moreover, in the said embodiment, the bluefin tuna (it is also called this tuna) was made into object as a tuna. However, it is considered that the present invention can be widely applied to other types of fish such as tuna such as yellowfin tuna, southern bluefin tuna, and bigeye tuna.

DESCRIPTION OF SYMBOLS 10 ... Swimming tank, 11 ... Intake pipe, 12 ... Drainage pit, 13 ... Drainage pipe, 14 ... Fume pump, 15 ... Pressure filtration apparatus, 16 ... UV sterilization apparatus, 17 ... Biological filtration tank, 18 ... Water supply pipe, 18a ... manual valve, 19 ... lighting equipment, 20 ... underground seawater water supply equipment, 21 ... intake pipe, 22 ... scooping water pump.

Claims (8)

A method for breeding, storing or transporting tuna underage fish in a swimming tank,
Filling the swimming tank with breeding water having a salinity of 15 psu or more and less than 30 psu;
Look including the step of introducing the immature of the tuna on the swimming bath,
A method for breeding, storing or transporting a tuna immature fish, characterized in that when the tuna immature fish is introduced into the swim tank, the water surface of the swim tank has a uniform illuminance . In the method for breeding, storing or transporting an immature fish of tuna according to claim 1,
A method for breeding, storing or transporting a tuna underage fish, characterized in that the swimming tank is installed in a building capable of blocking incident light from outside at night and taking in natural light during the daytime . A method for breeding, storing or transporting tuna underage fish in a swimming tank,
Filling the inside of the swimming tank installed in a building capable of blocking incident light from outside at night and taking in natural light during the day with breeding water having a salinity of 15 psu or more and less than 30 psu;
A method for breeding, storing or transporting the tuna underage fish, comprising the step of introducing the underage tuna fish into the swimming tank . In the method for breeding, storing or transporting an immature fish of tuna according to any one of claims 1 to 3,
A method for breeding, storing or transporting a tuna underage fish, comprising: introducing the underage tuna fish into the swimming tank and then adjusting a salinity environment of the swimming tank to 15 psu or more and 25 psu or less . In the method for breeding, storing or transporting a tuna underage fish according to any one of claims 1 to 4,
A method for breeding, storing, or transporting a tuna underage fish, comprising the step of adjusting a salt environment in the same swimming tank to 25 psu or more and less than 30 psu before introducing the underage tuna fish into the swimming tank . In the method for breeding, storing or transporting a tuna underage fish according to any one of claims 1 to 5,
After introducing Immature of the tuna on the swimming bath, breeding immature tuna characterized that you adjust at least 17psu or salinity of the breeding water, storage or transportation method. In the method for breeding, storing or transporting a tuna underage fish according to any one of claims 1 to 6,
A method for breeding, storing or transporting a tuna underwater fish, wherein after introducing the underwater tuna fish into the swimming tank, the salinity of the rearing water is adjusted to 20 psu ± 3 psu . In the method for breeding, storing or transporting a tuna underage fish according to any one of claims 1 to 7,
The breeding water, sea water, fresh water, salinity of immature tuna about 15psu or groundwater or the salinity characterized Rukoto configured to adjust the respective salt at about 15psu more underground spring water breeding, storage, or Transport method.

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