Method for selecting cultured fish stock, method for culturing fishes, cultured fish stock, package, facility for culturing fishes, fish obtained from crossbreeding of cultured fish, and method for increasing edible part of cultured fish

Abstract

Provided is a culturing facility comprising: a rearing water tank for rearing a cultured fish stock; an inspection device for performing a non-destructive inspection of a living cultured fish stock; and an information processing device that derives information relating to the amount of at least one organ on the basis of an inspection result acquired by the inspection device. Provided is a method for culturing fishes, comprising a selection step for selecting a parent fish from a cultured fish stock on the basis of information relating to the amount of at least one organ acquired during a non-destructive inspection of a living cultured fish stock.

Description

Methods for selecting farmed fish populations, methods for farming fish, farmed fish populations, packaging, fish farming equipment, fish obtained by crossbreeding farmed fish, and methods for increasing the edible portion of farmed fish.

[0001] This disclosure relates to a method for selecting a group of farmed fish, a method for farming fish, a group of farmed fish, packaging, fish farming equipment, fish obtained by crossbreeding farmed fish, and a method for increasing the edible portion of farmed fish.

[0002] From the perspective of resource conservation, various fish farming methods are being attempted. In fish farming, feed accounts for the majority of costs. Therefore, feed efficiency (FCR) is known as an indicator that shows the relationship between the amount of feed given and the amount of weight gained. Feed efficiency is the ratio of the amount of feed given to the amount of weight gained, and fish with a low FCR can efficiently gain weight with less feed. For this reason, FCR can be said to be an important indicator that affects the profitability and sustainability of aquaculture. For example, Non-Patent Literature 1 attempts to measure the FCR of turbot, a type of flatfish, and identify molecular markers that are significantly associated with FCR. Non-Patent Literature 2 investigates the relationship between physiological characteristics and FCR in king salmon.

[0003] Zhifeng Liu et al., “Genome-wide association study of feed conversion ratio in turbot (Scophthalmus maximus) based on genome resequencing”, Aquaculture Reports, Vol. 33, December 2023Jordan E. Elvy et al., “The relationship of feed intake, growth, nutrient retention, and oxygen consumption to feed conversion ratio of farmed saltwater Chinook salmon (Oncorhynchus tshawytscha)”, Aquaculture Reports, Vol. 554, May 30, 2022

[0004] This disclosure provides a method for selecting fish populations that enable efficient aquaculture, and a method for aquaculture fish. It also provides fish that can be efficiently aquacultured. Furthermore, it provides a fish population with reduced variability in feed efficiency, and a package containing such a fish population. It also provides a package containing a frozen fish population obtained by aquaculture with reduced variability in feed efficiency. Furthermore, it provides a fish farming facility that enables efficient aquaculture of fish. It also provides a method that can efficiently increase the edible portion of aquacultured fish.

[0005] One aspect of this disclosure provides a method (A) for selecting a group of farmed fish, comprising: an information acquisition step of performing non-destructive testing on a group of living farmed fish to obtain information regarding the quantity of at least one organ; and a selection step of selecting the group of farmed fish based on the information. In this disclosure, "living farmed fish" means farmed fish that can be farmed after inspection and / or measurement. Farming can be carried out, for example, by raising farmed fish in rearing tanks. By using farmed fish that are alive after inspection and / or measurement for farming, farmed fish that have obtained inspection and / or measurement results can be farmed continuously. For example, farmed fish that have obtained inspection and / or measurement results can be used as broodstock. In this disclosure, a group of farmed fish may be a group of farmed fish farmed in the same farming environment. The same aquaculture environment may be an aquaculture environment that satisfies at least one of the following conditions selected from the group consisting of (1) to (3): (1) eggs are collected at the same time from the same parent or lineage of farmed fish, (2) the fish are farmed in the same aquaculture farm, and (3) the fish are fed the same feed. The number of individuals in a farmed fish group may be, for example, more than the number of individuals that can live as a group if the farmed fish live in schools. The number of individuals in a farmed fish group may be, for example, 5 or more, 10 or more, 20 or more, 30 or more, 50 or more, or 100 or more. Alternatively, the number of individuals in a farmed fish group may be 1000 or less, 500 or less, 200 or less, or 100 or less.

[0006] One aspect of this disclosure provides a method (B) for selecting a group of farmed fish, comprising an information acquisition step of acquiring information on the quantity of at least one organ of a group of farmed fish, and a selection step of selecting the group of farmed fish based on the information.

[0007] The amount of at least one organ obtained in the information acquisition step of the fish farming school selection method (A) or (B) is significantly correlated with feed efficiency. Feed efficiency is the ratio of the amount of feed to the amount of weight gain, and is referred to as "FCR" in this disclosure. By selecting the fish farming school based on information on the amount of at least one organ in the selection step, it is possible to obtain a fish farming school with reduced variability in FCR. Therefore, according to the fish farming school selection method (A) or (B), it is possible to easily manage the amount of feed and selectively cultivate a fish farming school with a low FCR. Thus, according to the fish farming school selection method (A) or (B), fish can be cultivated efficiently.

[0008] One aspect of this disclosure provides a method for cultivating fish (C), which includes a step of selecting at least a portion of a group of cultured fish selected by method (A) or (B) of a group of cultured fish in which the ratio of the predicted weight of at least one organ to the body weight of the fish is less than or equal to a predetermined value, and using these as parent fish. In this disclosure, the predicted weight of an organ is a numerical value obtained by estimating the weight of the organ based on its cross-sectional area.

[0009] One aspect of this disclosure provides a method for cultivating fish (D), which includes the step of selecting broodstock fish in which the ratio of the weight of at least one organ to the body weight of the fish is less than or equal to a predetermined value.

[0010] The ratio of the predicted weight of at least one organ to the body weight of the fish is strongly correlated with the FCR. In fish farming methods (C) or (D), fish with this ratio below a predetermined value are used as broodstock, thus enabling efficient fish farming.

[0011] One aspect of this disclosure provides a method (E) for cultivating fish, comprising a selection step of selecting broodstock from a population of live farmed fish based on information regarding the quantity of at least one organ obtained by non-destructive testing of the population of said fish.

[0012] The amount of at least one organ used in the selection process in the fish farming method (E) is significantly correlated with FCR. Since broodstock are selected in the selection process based on information regarding the amount of at least one organ, a farmed fish population with a low FCR can be easily obtained. Therefore, fish can be farmed efficiently according to the fish farming method (E).

[0013] One aspect of this disclosure provides a method (F) for cultivating fish, comprising an information acquisition step of acquiring information on the quantity of at least one organ of a group of farmed fish, and a selection step of selecting the group of farmed fish based on the information.

[0014] In the fish farming method (F), the amount of at least one organ obtained in the information acquisition step is significantly correlated with feed efficiency. In the selection step, by selecting the farmed fish population based on information regarding the amount of at least one organ, it is possible to obtain a farmed fish population with reduced variability in FCR. Therefore, according to the fish farming method (F), it is possible to easily manage the amount of feed and selectively farm aquaculture fish populations with low FCR. Thus, according to the fish farming method (F), fish can be farmed efficiently.

[0015] One aspect of this disclosure is to provide a group of farmed fish (G) in which, when the ratio of the weight of the pyloric caeca and liver to the body weight of the fish is called the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals in a farmed fish group contained in a single rearing tank is 0.04 or less.

[0016] The ratio of pyloric caeca and liver weight to body weight in a farmed fish population (G) correlates strongly with FCR. Since the standard deviation of either or both of the pyloric caeca ratio and liver ratio for all individuals in farmed fish population (G) is below a predetermined value, the variability in FCR among individuals can be sufficiently reduced. Therefore, individual size differences during continued farming can be reduced. Furthermore, reducing FCR can lower production costs.

[0017] One aspect of the present disclosure is a cultured fish group housed in a container, wherein when the ratios of the weights of the pyloric caeca and the liver to the body weight of the fish are defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio of all individuals of the cultured fish group housed in the container is 0.04 or less. A cultured fish group (H) is provided.

[0018] In the cultured fish group (H), the ratios of the weights of the pyloric caeca and the liver to the body weight of the fish are strongly correlated with the FCR. Since the standard deviation of one or both of the pyloric caeca ratio and the liver ratio of all individuals of the cultured fish group (H) is a predetermined value or less, the cultured fish group (H) is cultured with a sufficiently small variation in FCR among individuals. Therefore, the cultured fish group (H) tends to have small individual differences in size and shape and high commercial value.

[0019] One aspect of the present disclosure is a package comprising a container and a frozen cultured fish group housed in the container, wherein when the ratios of the weights of the pyloric caeca and the liver to the body weight of each of the frozen cultured fish group are defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio of all individuals of the frozen cultured fish group housed in the container is 0.04 or less. A package (I) is provided.

[0020] In the package (I), the frozen cultured fish group has a small variation in the ratios of the weights of the pyloric caeca and the liver to the body weight of the fish. Therefore, the uniformity of the body weight and shape of the fish tends to be high. In addition, the ratios of the weights of the pyloric caeca and the liver to the body weight of the fish are strongly correlated with the FCR. The frozen cultured fish group in the package (I) is obtained by culturing with a sufficiently small variation in FCR. Therefore, the frozen cultured fish group in the package (I) tends to have small individual differences in size and shape and high commercial value.

[0021] One aspect of the present disclosure provides a fish culture facility (J) comprising a culture tank for culturing a cultured fish group, an inspection device for performing a non-destructive inspection of the living cultured fish group, and an information processing device for deriving information regarding the amount of at least one organ based on the inspection results obtained by the inspection device.

[0022] Information on the quantity of at least one organ derived by the information processing device in the fish farming equipment (J) is significantly correlated with the FCR. By using such information, it becomes easier to manage the feeding amount, or it is possible to selectively farm the fish farming group with a small FCR. Therefore, the fish farming equipment (J) can efficiently farm fish.

[0023] One aspect of the present disclosure provides a fish (K) obtained by mating farmed fish selected by the farmed fish sorting method (A) or (B), or the fish farming method (F). Such fish (K) shows the same tendency of FCR as the farmed fish selected by the farmed fish sorting method (A) or (B), or the fish farming method (E) or (F). For example, fish obtained by mating farmed fish with a small FCR can be efficiently farmed with less feed.

[0024] One aspect of the present disclosure provides a method (L) for increasing the edible part of farmed fish by farming the farmed fish belonging to the farmed fish group selected by the farmed fish sorting method (A) or (B), or the fish farming method (F). In this method (L), since the farmed fish selected by the farmed fish sorting method (A) or (B), or the fish farming method (E) or (F) is farmed, the edible part of the farmed fish can be efficiently increased at a low production cost.

[0025] The present disclosure can provide a method for selecting a farmed fish group capable of efficiently farming fish and a method for farming fish. In addition, it is possible to provide fish that can be efficiently farmed. The present disclosure can provide a farmed fish group with reduced variation in feed efficiency and a package including such a farmed fish group. In addition, it is possible to provide a package including a frozen farmed fish group obtained by farming in a state where the variation in feed efficiency is reduced. The present disclosure can provide a fish farming equipment capable of efficiently farming fish. In addition, it is possible to provide a method capable of efficiently increasing the edible part of farmed fish.

[0026] This figure shows an example of aquaculture equipment. This figure shows an example of an inspection device and an information processing device. This figure shows the correlation between feed efficiency and the ratio of the total weight of internal organs to body weight. This figure shows the correlation between feed efficiency and the ratio of the weight of the pyloric caeca to body weight. This figure shows the correlation between feed efficiency and the ratio of the weight of the liver to body weight.

[0027] Embodiments of this disclosure will be described below, with reference to the drawings as appropriate. However, the following embodiments are illustrative for the purpose of illustrating this disclosure and are not intended to limit this disclosure to the following. In the description, the same reference numerals will be used for elements that are the same or have the same function, and redundant explanations will be omitted as appropriate. Positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings unless otherwise specified. The dimensional ratios of each element are not limited to the ratios shown. In these embodiments, numerical ranges indicated by "~" include numerical values ​​indicated as upper and lower limits. Numerical ranges in which the upper and lower limits of a numerical range are replaced with the values ​​of the embodiment are also included in this disclosure. If a numerical range is illustrated with only an upper limit or only a lower limit, a numerical range combining the numerical range with only an upper limit and the numerical range with only a lower limit is also included in this disclosure. Numerical ranges in which the upper and / or lower limits of one numerical range are replaced with the upper and / or lower limits of another numerical range are also included in this disclosure. Multiple examples of substances and materials may be used individually or in combination of two or more arbitrarily selected types. This disclosure also includes applying the concepts described in one embodiment to another embodiment.

[0028] The fish species of fish and farmed fish in the following embodiments are not particularly limited. The contents described in each embodiment are also applicable to fish species that live in schools. Therefore, there is a high degree of freedom in selecting fish species. From this perspective, the fish species in each embodiment may be marine fish belonging to the order Perciformes or Pleuronectiformes. Examples of marine fish belonging to the order Perciformes include marine fish belonging to the family Scombridae or Carangidae. Examples of Scombridae include marine fish belonging to the genera Thunnus, Skipjack Tuna, Bonito, or Frigate Mackerel. Examples of Carangidae include marine fish belonging to the genera Scomberetta, Jack, Mackerel, Bigeye, and Giant Trevally. Examples of marine fish belonging to the order Pleuronectiformes include marine fish belonging to the family Pleuronectidae or Soleidae. Examples of Pleuronectidae include marine fish belonging to the genera Sole, Stonefish, Redfin, or Blackfin. The family Pleuronectidae includes marine fish belonging to the genera Pleuronectes, Halibut, Sole, and Red Sole. Marine fish may include at least one species selected from the group consisting of yellowtail (Seriola quinqueradiata), greater amberjack (Seriola dumerili), kingfish (Seriola lalandi), striped jack (Pseudocaranx dentex), bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), and southern bluefin tuna (Thunnus maccoyii), which are suitable for aquaculture.

[0029] In the following embodiments, "non-destructive testing" refers to a method of testing fish without damaging the fish body during the test, and can be performed using commercially available non-destructive testing equipment. Non-destructive testing allows fish to be tested while they are still alive. As a non-destructive testing method, at least one selected from the group consisting of ultrasound, MRI, and CT scans may be used. Of these, ultrasound may be used from the viewpoint of workability and convenience in aquaculture farms. In the following embodiments, "parent fish" refers to individuals used to produce the next generation of fish (seedlings) through mating.

[0030] In each of the following embodiments, "at least one organ" may be one or more organs included in the internal organs, or it may be the entire internal organ. "At least one organ" may include, for example, at least one selected from the group consisting of the pyloric caeca, liver, stomach, and intestines. From the viewpoint of sufficiently increasing the prediction accuracy of FCR, "at least one organ" may include at least one selected from the group consisting of the pyloric caeca and liver, and may include the pyloric caeca. In the case of farmed fish, compound feed is often provided, which can cause the pyloric caeca to develop. Therefore, including the pyloric caeca as "at least one organ" can reduce measurement errors.

[0031] <Method for selecting a group of farmed fish> One embodiment of the method for selecting a group of farmed fish includes an information acquisition step of performing a non-destructive test on a group of living farmed fish to obtain information on the quantity of at least one organ, and a selection step of selecting a group of farmed fish based on the said information.

[0032] In the information acquisition process, information on at least one organ of each farmed fish in the fish population can be obtained. Non-destructive testing of the fish population may be performed on individual fish or on multiple fish together. The information may be, for example, information on the size or weight of at least one organ. Information on size may include length, cross-sectional area, and volume. Information acquisition may be performed using anesthetized fish populations. However, anesthesia is not mandatory; for example, information on the quantity of at least one organ may be obtained from a fish population swimming in a tank using non-destructive testing equipment installed inside or around the tank. When acquiring this information, the location of a cross-section that can predict the quantity of at least one organ with high accuracy may be identified in advance.

[0033] Information regarding the volume of at least one organ (hereinafter sometimes referred to as "organ information") may be obtained from a three-dimensional image or a two-dimensional image. The organ information may include a cross-sectional image of the fish body and may include the cross-sectional area of ​​at least one organ determined from the cross-sectional image. The cross-sectional image may include a longitudinal cross-sectional image of the fish body or a transverse cross-sectional image. A transverse cross-sectional image is a cross-section perpendicular to the direction in which the spine extends, and a longitudinal cross-sectional image is a cross-sectional image parallel to the direction in which the spine extends. From the viewpoint of the size of the detector such as the probe used in non-destructive testing, the cross-sectional image may be a transverse cross-sectional image of the fish body.

[0034] When acquiring information on the pyloric caeca as organ information, a cross-sectional image of the fish body between the 2nd and 19th vertebrae may be used. This allows for a highly accurate estimation of the volume of the pyloric caeca. From a similar viewpoint, a cross-sectional image of the fish body between the 4th and 9th vertebrae, or near the base of the pelvic fin, may be used. This allows for an even higher accuracy estimation of the volume of the pyloric caeca. From the viewpoint of estimating the volume of the pyloric caeca with even higher accuracy, a cross-sectional image of the fish body at the base of the pelvic fin may be used. That is, a cross-sectional image including at least a portion of the base of the pelvic fin may be used.

[0035] When obtaining liver information as organ information, cross-sectional images of the fish body between the second and thirteenth vertebrae may be used. This allows for a highly accurate estimation of liver volume.

[0036] Organ information may be obtained from cross-sectional images using image processing software, or it may be obtained using measurement functions provided in a non-destructive testing device. For example, an operator may calculate the length or cross-sectional area of ​​at least one organ using a cross-sectional image displayed on a monitor or a printed photograph. By including the cross-sectional area of ​​the organ, the weight of the organ can be predicted with high accuracy. Thus, a prediction step may be performed to predict the weight of at least one organ based on the organ information.

[0037] In the prediction step, the weight of the pyloric caeca is predicted based on, for example, the size of at least one organ, such as its cross-sectional area. The relationship (correlation formula) between the size and weight of at least one organ may change depending on the fish's body weight. For this reason, a weight measurement step may be performed to measure the fish's body weight. This allows for the selection of a correlation formula according to the fish's body weight. Therefore, the weight of at least one organ can be predicted with even greater accuracy. The weight measurement step may be performed before or after the information acquisition step. For example, the weight measurement step may be performed between the information acquisition step and the prediction step.

[0038] The information regarding the quantity of at least one organ may be the ratio of the predicted weight of at least one organ to the body weight of each farmed fish. Since this ratio has a sufficiently strong correlation with FCR, sorting according to the size of FCR can be performed with sufficiently high accuracy. Alternatively, the information regarding the quantity of at least one organ may be the ratio of the actually measured weight of at least one organ to the actual body weight of each farmed fish. By measuring the body weight and the weight of at least one organ during dismantling at the time of shipment and using this for sorting, sorting can be performed without obtaining the predicted values ​​in the above prediction process. Eggs or sperm may be collected from the sorted individuals during or before dismantling and used for breeding.

[0039] The average weight of each fish in a farmed fish population may be 100g or more, 200g or more, 300g or more, 350g or more, or 400g or more. Early selection after the start of farming allows for efficient farming. This makes it possible to predict the FCR of the farmed fish population with high accuracy. The average weight of each fish in a farmed fish population may be 10kg or less, 8kg or less, 6kg or less, 4kg or less, or 2kg or less. Appropriate fish can be selected as broodstock in time for shipment. The weight of each fish in a farmed fish population may be 100g to 10kg, 200g to 8kg, or 300g to 6kg, 350g to 4kg, or 400g to 2kg.

[0040] In the prediction process, statistical data or machine learning models may be used to predict the weight of at least one organ. Statistical data may include, for example, a correlation formula obtained by statistically processing the cross-sectional area of ​​at least one organ and the actual measured weight of at least one organ contained in the fish. Such a correlation formula can be obtained by statistically processing the cross-sectional area of ​​at least one organ contained in the fish and the measured weight of at least one organ. For example, when there is a high correlation between the cross-sectional area of ​​a particular organ and its weight, the relationship between the cross-sectional area and weight can be expressed in an equation using the least squares method. By substituting the cross-sectional area of ​​the particular organ into this equation, a predicted weight of that organ can be obtained. Different correlation formulas may be prepared for each fish weight. The relationship between organ information and organ weight may differ depending on the fish species. Therefore, prediction accuracy can be improved by preparing statistical data for each fish species.

[0041] A machine learning model may be constructed using, for example, the cross-sectional area of ​​at least one organ contained in the fish body, the actual measured weight of the fish body, and the weight of at least one organ as training data. In this case as well, training data may be prepared and trained for each fish species. The machine learning model may have an algorithm to improve prediction accuracy based on the discrepancy between the predicted value and the actual value of the weight of at least one organ.

[0042] In the sorting process, the farmed fish population is sorted based on the information obtained in the information acquisition process. This sorts the farmed fish population into multiple groups. In the sorting process, the farmed fish population may be divided into, for example, a first farmed fish population and a second farmed fish population that has a larger amount of at least one organ than the first farmed fish population. This sorts the population into, for example, a first farmed fish population and a second farmed fish population that has a higher FCR than the first farmed fish population. The relationship between the FCRs of each farmed fish population can be as follows. Note that the FCR of each farmed fish population is the average value of the FCR of each farmed fish belonging to that population. First farmed fish population < Farmed fish population before sorting process < Second farmed fish population

[0043] The first group of farmed fish grows efficiently with less feed. Therefore, if the farming process involves cultivating the first group of farmed fish after the selection process, feed costs can be reduced. Some or all of the farmed fish belonging to the selected first group of farmed fish may be used as broodstock. This allows for a higher proportion of farmed fish with a low FCR (Food Critical Ratio). The second group of farmed fish may also be farmed continuously, or farming may be stopped and the fish shipped.

[0044] In the sorting process, the farmed fish population may be sorted into three or more groups based on the information obtained in the information acquisition process. This allows the farmed fish population to be sorted into n groups, such as the first farmed fish population, the second farmed fish population, the third farmed fish population, ... the nth farmed fish population, according to the size of the FCR. Each sorted group may contain multiple farmed fish. Therefore, this sorting method can be suitably applied to fish species that behave in groups. The farming process may be carried out in which only k groups out of the n groups whose FCR is below a predetermined value are farmed. Here, n and k are natural numbers of 2 or greater, and n ≥ k or n > k. n - k may be 1 or greater, 2 or greater, or 3 or greater.

[0045] Among the n groups, the ratio of the FCR of the nth aquaculture fish group with the largest FCR to the FCR of the first aquaculture fish group with the smallest FCR may be 1.3 or higher, 1.5 or higher, or 1.7 or higher, from the viewpoint of obtaining aquaculture fish groups with sufficiently suppressed feed costs. The upper limit of this ratio may be, for example, 5.0 or 4.0, from the viewpoint of sufficiently maintaining the number of fish in the aquaculture fish groups. The numerical range of this ratio may be 1.3 to 5.0, 1.5 to 4.0, or 1.7 to 4.0.

[0046] The FCR of a farmed fish population can be determined as follows: Total body weight (TW) of the fish population at the start of measurement. ｉ ) is measured. Then, the fish are farmed while being fed for a predetermined period. After the predetermined period has elapsed, the total weight (TW) of the fish in the farmed group is measured. ｆ ) Measure the measured TW ｉ and TW ｆ Using the total amount of feed (TF) given over a specified period, the FCR can be calculated using the following formula: FCR = TF / (TW ｆ-TW ｉ )

[0047] The information acquisition process, weight measurement process, prediction process, selection process, and farming process in the method for selecting farmed fish may be repeated. This makes it possible to obtain a farmed fish population with a sufficiently low FCR. Such a farmed fish population can increase the edible portion while reducing feed costs.

[0048] By cultivating farmed fish selected using the selection method of this embodiment, the edible portion of the farmed fish can be increased. This is because selecting fish with a small proportion of pyloric caecae means selecting fish with a relatively large proportion of other parts that contain edible tissue. Therefore, the selection method of this embodiment can also be described as a method for increasing the edible portion of farmed fish.

[0049] <Method for cultivating fish, and fish obtained by crossbreeding farmed fish> One embodiment of the method for cultivating fish includes a step of using as parent fish at least a portion of the farmed fish population selected by the farmed fish population selection method according to the above embodiment, in which the ratio of the predicted value of the weight of at least one organ to the body weight of the fish is less than or equal to a predetermined value. Fish (seedlings) obtained by crossbreeding farmed fish according to one embodiment may be obtained in this step. For example, male and female individuals may be selected from the farmed fish population, and these individuals may be crossbred to obtain new fish.

[0050] Fish whose ratio of the predicted weight of at least one organ to the body weight of the fish is less than or equal to a predetermined value may belong to the first aquaculture fish group selected in the selection step of the aquaculture fish group selection method according to the above embodiment. The ratio of the predicted weight of at least one organ to the body weight of the fish has a sufficiently strong correlation with FCR. Therefore, fish with a small ratio tend to have a sufficiently small FCR. By using such fish as parent fish, it is possible to produce aquaculture fish with a sufficiently small FCR. Thus, fish can be farmed efficiently.

[0051] Another embodiment of a fish farming method includes a selection step of selecting broodstock from a fish farm based on information regarding the quantity of at least one organ obtained by non-destructive testing of a living fish farm. In this farming method, the fish farm may be divided into multiple groups, and fish belonging to any of the selected groups may be selected as broodstock. Alternatively, any fish belonging to a group may be selected as broodstock without dividing the fish into multiple groups. The broodstock selected in this way have a low FCR. By mating the selected male and female broodstock, seedlings with a low FCR can be produced. Fish farmed in which the weight of at least one organ is small relative to body weight tend to have high digestive enzyme activity. This is thought to be because even though the organs are small, the digestive and absorptive efficiency is good, resulting in a low FCR value.

[0052] <Cultivated Fish School and Packaging> The cultivated fish school according to the first embodiment may be contained in a single rearing tank and may be alive. When the ratio of the weight of the pyloric caeca and liver to the body weight of the fish is called the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio of all individuals in the cultivated fish school contained in a single rearing tank may be 0.04 or less, 0.03 or less, or 0.02 or less. The standard deviation of one or both of the pyloric caeca ratio and the liver ratio of all individuals in the cultivated fish school contained in a single rearing tank may be 0.0001 or more, 0.0002 or more, or 0.0003 or more. The number of cultivated fish in a cultivated fish school where the standard deviation of one or both of the pyloric caeca ratio and the liver ratio of all individuals in the cultivated fish school contained in a single rearing tank is 0.04 or less, 0.03 or less, or 0.02 or less may be 5 or more, 10 or more, 20 or more, or 30 or more. Furthermore, the number of individuals in a farmed fish population where the standard deviation of one or both of the pyloric caeca ratio and liver ratio of all individuals in a single rearing tank is 0.04 or less, 0.03 or less, or 0.02 or less may be 1,000 or less, 500 or less, 200 or less, 100 or less, or 50 or less.

[0053] In the first embodiment, the ratio of the weight of the pyloric caeca and liver to the body weight of the farmed fish population tends to correlate strongly with the FCR. In the first embodiment, since the standard deviation of one or both of the pyloric caeca ratio and liver ratio of all individuals in the farmed fish population is below a predetermined value, the variation in FCR among individuals can be sufficiently reduced. Therefore, individual differences in size can be reduced when farming is continued. Furthermore, by reducing the FCR, farming costs can also be reduced.

[0054] The farmed fish population according to the second embodiment is a farmed fish population housed in a container and does not need to be alive. In the "method for selecting farmed fish populations," "farmed fish population" refers to a farmed fish population that is subject to selection, but in this embodiment, "farmed fish population" may refer to a farmed fish population after selection has been completed. When the ratio of the weight of the pyloric caeca and liver to the body weight of the fish is defined as the pyloric caeca ratio and liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and liver ratio for all individuals of the farmed fish population housed in the container may be 0.04 or less, 0.03 or less, or 0.02 or less. The standard deviation of one or both of the pyloric caeca ratio and liver ratio for all individuals of the farmed fish population housed in the container may be 0.0001 or more, 0.0002 or more, or 0.0003 or more. The container may be, for example, a box made of styrofoam. The number of individuals in a container of farmed fish may be 5 or more, 10 or more, 20 or more, or 30 or more. Alternatively, the number of individuals in a container of farmed fish may be 500 or less, 200 or less, 100 or less, or 50 or less.

[0055] In the first and second embodiments, the variation in the ratio of the weight of the pyloric caeca and liver to the body weight of the farmed fish populations is small, resulting in a tendency for high uniformity in body weight and shape. Furthermore, the farmed fish populations in the first and second embodiments may be farmed with sufficiently small variation in FCR between individuals. Consequently, the farmed fish populations in the first and second embodiments tend to have small individual differences in size and shape and high commercial value.

[0056] A packaging according to one embodiment comprises a container and a frozen farmed fish population contained in the container. In this disclosure, freezing includes -20°C or below, chilling, and refrigeration. When the ratio of the weight of the pyloric caeca and liver to the body weight of each frozen farmed fish population is defined as the pyloric caeca ratio and liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and liver ratio for all individuals of the frozen farmed fish population contained in the container may be 0.04 or less, 0.03 or less, or 0.02 or less. The standard deviation of one or both of the pyloric caeca ratio and liver ratio for all individuals of the frozen farmed fish population contained in the container may be 0.0001 or more, 0.0002 or more, or 0.0003 or more. The container may be, for example, a box made of polystyrene foam. Such a packaging can be transported smoothly. The number of individuals of the frozen farmed fish population contained in the container may be 5 or more, 10 or more, 20 or more, or 30 or more. Furthermore, the number of frozen farmed fish contained in the container may be 500 or less, 200 or less, 100 or less, or 50 or less.

[0057] The low variation in the ratio of pyloric caeca and liver weight to body weight in frozen farmed fish populations contained in containers indicates a high degree of uniformity in body weight and shape. Furthermore, frozen farmed fish populations contained in containers may be farmed with sufficiently low variation in FCR between individuals. Therefore, frozen farmed fish populations contained in containers tend to have less individual variation in size and shape and thus higher commercial value.

[0058] <Fish farming equipment> Fish farming equipment according to one embodiment includes a rearing tank for raising a school of farmed fish, an inspection device for performing non-destructive testing of a school of farmed fish in a living state, and an information processing device for predicting the quantity of at least one organ based on information of at least one organ obtained by the inspection device.

[0059] An example of this embodiment, the aquaculture facility 100 shown in Figure 1, may include a rearing tank 10 for raising a group of farmed fish F0, an inspection device 20 for performing non-destructive testing of the group of farmed fish F0, an information processing device 30 for deriving information regarding the quantity of at least one organ based on the inspection results obtained by the inspection device 20, a first rearing tank 11 for raising a first group of farmed fish F1 selected from the group of farmed fish F0, and a second rearing tank 12 for raising a second group of farmed fish F2 selected from the group of farmed fish F0.

[0060] The rearing tank 10 may contain water WA, such as seawater, and the farmed fish group F0 may be raised in the water WA. The inspection device 20 may be configured to obtain inspection results for at least one organ without damaging the fish body during inspection. The inspection device 20 may include, for example, a non-destructive inspection unit 21 that obtains inspection results for each individual of the farmed fish group F0 by non-destructive inspection, as shown in Figure 2, and a weight measuring unit 25 that measures the weight of each individual of the farmed fish group F0.

[0061] The non-destructive testing unit 21 in Figure 2 may include a probe 22 having an ultrasonic transducer that emits ultrasonic waves and detects reflected waves (echoes) bounced back from the tissue of the fish body 50, a control unit 24 that exchanges signals with the probe 22 and outputs an image signal to be displayed on the display unit, and a first display unit 26 that displays a cross-sectional image (echo image) based on the image signal.

[0062] The probe 22 may detect reflected waves by applying it to the measurement site of the fish body 50. An operator may calculate the length or cross-sectional area of ​​the cross section of at least one organ along a predetermined direction using a cross-sectional image of the fish body 50 displayed on the first display unit 26 or a printed photograph. Alternatively, the control unit 24 may calculate the length or cross-sectional area of ​​the cross section of at least one organ along a predetermined direction and display it on the first display unit 26. The control unit 24 may include, for example, a transmitting unit that generates an electrical pulse signal to be applied to the ultrasonic transducer, a receiving unit that receives reflected signals from the probe 22, a converter that converts the reflected signals received by the receiving unit into image signals, and a calculation unit that calculates the cross-sectional area of ​​the pyloric caeca from the cross-sectional image. The control unit 24 and the first display unit 26 may be configured as separate hardware or as an integrated unit. The non-destructive testing unit 21 may be a commercially available ultrasonic testing device.

[0063] Before performing the inspection in the non-destructive testing unit 21, the farmed fish group F0 may be anesthetized. By anesthetizing, stable images can be acquired by non-destructive testing. The anesthesia is not particularly limited as long as it fixes the fish body for a certain period of time and allows for stable images to be acquired by non-destructive testing. For example, each individual in the farmed fish group may be immobilized by anesthesia using an anesthetic such as 2-phenoxyethanol or eugenol, electric shock, acoustic shock, or vibration shock. The first display unit 26 may be composed of a normal monitor. The weighing instrument 27 used in the weight measuring unit 25 may be a normal scale.

[0064] The information processing device 30 may include a calculation unit 32 that derives a ratio of the predicted weight of at least one organ to body weight based on the inspection results of the non-destructive testing unit 21 displayed on the first display unit 26 and the measured body weight from the weight measurement unit 25, and a second display unit 34 that displays the predicted value calculated by the calculation unit 32. The calculation unit 32 may receive the inspection results of at least one organ from the non-destructive testing unit 21 and the measured body weight from the weight measurement unit 25 as input. The calculation unit 32 may perform calculations using statistical data or a machine learning model and output the ratio of the weight of at least one organ to body weight. The second display unit 34 may display the ratio of the weight of at least one organ to body weight. The calculation unit 32 may be configured as a normal computer, and the second display unit 34 may be configured as a normal monitor.

[0065] In Figure 2, the control unit 24 and the calculation unit 32 are shown as separate components, but they may be configured as a single piece of hardware or as separate pieces of hardware. The first display unit 26 and the second display unit 34 may also be separate monitors or as a single monitor. In the latter case, for example, the system may be configured to simultaneously display a cross-sectional image, body weight, a predicted weight of at least one organ, and the ratio of the predicted weight of at least one organ to body weight.

[0066] In the example shown in Figure 2, the non-destructive testing unit 21 may be equipped with an ultrasonic testing device, from the viewpoint of workability and convenience in the aquaculture farm. Ultrasonic testing devices have the advantage of being inexpensive and compact, making them easy to bring into the aquaculture farm and use. However, the non-destructive testing unit 21 is not limited to an ultrasonic testing device, and may be equipped with an MRI or CT scanner instead. These have the advantage of being excellent at capturing the entire fish body and obtaining clearer images.

[0067] For example, if the non-destructive testing unit 21 is equipped with an MRI inspection device, it may include a superconducting magnet for generating a magnetic field, a transmitting unit (high-frequency coil) for transmitting radio waves, a gradient magnetic field coil unit for changing the magnetic field, and a receiving unit (receiving coil) for receiving radio waves from inside the fish body. The MRI inspection device can obtain cross-sectional images of the fish body by utilizing magnetism, electromagnetic waves, and the movement of hydrogen atoms. If the non-destructive testing unit 21 is equipped with a CT inspection device, the CT inspection device may include an X-ray tube for irradiating the fish body with X-rays, a detector for detecting the X-rays that have passed through the fish body, and a drive unit for rotating the X-ray tube and the detector. Commercially available MRI and CT inspection devices can be used.

[0068] Based on the information on the quantity of at least one organ derived by the information processing device 30, the farmed fish group F0 is sorted into a first farmed fish group F1 and a second farmed fish group F2. In the example in Figure 2, the information on the quantity of at least one organ may be derived as the ratio α of the predicted weight of at least one organ to the body weight of each individual fish in farmed fish group F0, as measured by the weighing device 27 of the weight measuring unit 25. If the average values ​​of the ratio α of farmed fish group F0, the first farmed fish group F1, and the second farmed fish group are α0, α1, and α2, respectively, then their relative sizes may be as follows: α1 < α0 < α2

[0069] The ratio α of each individual in the cultured fish group F0 is highly correlated with the FCR of each individual in the cultured fish group F0. Therefore, the FCR of the first cultured fish group F1 tends to be lower than that of the cultured fish group F0 and the second cultured fish group F2. On the other hand, the FCR of the second cultured fish group F2 tends to be higher than that of the first cultured fish group F1 and the second cultured fish group F0.

[0070] As shown in Figure 1, the aquaculture facility 100 may include a first rearing tank 11 for raising a first group of farmed fish F1 and a second rearing tank 12 for raising a second group of farmed fish F2. In the first rearing tank 11 and the second rearing tank 12, the first group of farmed fish F1 and the second group of farmed fish F2, after being returned to water WA, may be awakened from anesthesia. Since the FCR of the first group of farmed fish F1 is smaller than that of the second group of farmed fish F2, the first group of farmed fish F1 in the first rearing tank 11 can be farmed while keeping feed costs down compared to the second group of farmed fish F2 in the second rearing tank 12. Male and female individuals may be selected from the first group of farmed fish F1 in the first rearing tank 11, and these individuals may be bred to obtain new fish. Fish obtained in this way tend to have a small FCR, so they can be farmed while reducing feed costs.

[0071] In the aquaculture facility 100, the sorting of the aquaculture fish group F0 may be performed manually by an operator, or it may be performed using a sorting device equipped with a transport unit and a switching unit that switches between transport destinations. The inspection by the inspection device 20, the extraction of information regarding the quantity of at least one organ by the information processing device 30, and the sorting of the aquaculture fish group may be performed multiple times at predetermined intervals. For example, the inspection device 20 may be used to inspect individuals of the first aquaculture fish group F1, information regarding the quantity of at least one organ may be extracted by the information processing device 30, and the first aquaculture fish group F1 may be sorted into multiple groups. This makes it possible to obtain groups with an FCR even smaller than that of the first aquaculture fish group F1.

[0072] In the aquaculture facility 100, the F0 population of farmed fish is selected based on an indicator that significantly correlates with the FCR. This allows for the selective cultivation of farmed fish populations with low FCRs. The aquaculture facility 100 enables efficient fish farming.

[0073] As described above, this disclosure includes the following embodiments: [1] A method for selecting a group of farmed fish, comprising: an information acquisition step of performing a non-destructive inspection of a group of living farmed fish to obtain information regarding the quantity of at least one organ; and a selection step of selecting the group of farmed fish based on the information. [2] The method for selecting a group of farmed fish according to [1], further comprising a prediction step of predicting the weight of the at least one organ based on the information, wherein the selection step selects the group of farmed fish based on the predicted weight of the at least one organ. [3] The method for selecting a group of farmed fish according to [2], further comprising a weight measurement step of measuring the weight of each of the farmed fish, wherein the selection step selects the group of farmed fish based on the ratio of the predicted weight of the at least one organ to the weight of each of the farmed fish. [4] The method for selecting a group of farmed fish according to any one of [1] to [3], wherein the selection step selects the group of farmed fish, each having a weight within a predetermined range. [5] The method for selecting a group of farmed fish according to [4], wherein the weight within the predetermined range is 300 g or more. [6] The method for selecting a group of farmed fish according to any one of [1] to [5], further comprising a farming step of releasing at least a portion of the group of farmed fish selected in the selection step into a rearing tank for farming. [7] The method for selecting a group of farmed fish according to any one of [1] to [6], wherein the information includes the cross-sectional area of ​​at least one organ obtained from cross-sectional images of each of the group of farmed fish. [8] The method for selecting a group of farmed fish according to any one of [1] to [7], wherein the non-destructive inspection includes an ultrasonic inspection. [9] The method for selecting a group of farmed fish according to any one of [1] to [8], wherein the at least one organ includes either the pyloric caeca and the liver or both.

[10] The method for selecting a group of farmed fish according to any one of [1] to [9], wherein the group of farmed fish includes marine fish.

[11] A method for selecting a group of cultured fish according to any one of [1] to

[10] , wherein the group of cultured fish includes the genus Sargassum.

[12] A method for cultivating fish, comprising the step of using as parent fish at least a portion of the group of cultured fish selected by the method for selecting a group of cultured fish according to any one of [1] to

[11] above, in which the ratio of the predicted value of the weight of at least one organ to the body weight of the fish is less than or equal to a predetermined value.

[13] A method of farming fish, comprising a selection step of selecting parent fish from a farmed fish population based on information regarding the quantity of at least one organ obtained by non-destructive testing of the living farmed fish population.

[14] A farmed fish population in which, when the ratio of the weight of the pyloric caeca and liver to the body weight of the fish is defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals of the farmed fish population contained in one rearing tank is 0.04 or less.

[15] A farmed fish population contained in a container, wherein when the ratio of the weight of the pyloric caeca and liver to the body weight of the fish is defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals of the farmed fish population contained in the container is 0.04 or less.

[16] A packaging comprising a container and a frozen farmed fish population contained in the container, wherein when the ratio of the weight of the pyloric caeca and the liver to the body weight of each frozen farmed fish population is defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals of the frozen farmed fish population contained in the container is 0.04 or less.

[17] A fish farming facility comprising a rearing tank for raising a fish population, an inspection device for performing non-destructive testing of the living fish population, and an information processing device for deriving information regarding the quantity of at least one organ based on the inspection results obtained by the inspection device.

[18] The fish farming facility according to

[17] , wherein the inspection device comprises a weight measuring unit for measuring the body weight of the fish population, and the information processing device derives the ratio of the weight of at least one organ to the body weight from the body weight and the weight of at least one organ predicted based on the inspection results.

[19] Fish farming equipment according to

[18] , comprising a first rearing tank for raising a first group of farmed fish and a second rearing tank for raising a second group of farmed fish, wherein the average value of the ratio of the first group of farmed fish and the average value of the ratio of the second group of farmed fish are different from each other.

[20] Fish obtained by crossbreeding farmed fish selected by the farmed fish group selection method according to any one of [1] to

[11] above.

[21] A method for increasing the edible portion of farmed fish by farming farmed fish belonging to a group of farmed fish selected by the farmed fish group selection method according to any one of [1] to

[11] above.

[22] An information acquisition step of acquiring information on the amount of at least one organ of a cultured fish group, and a sorting step of sorting the cultured fish group based on the information. A method for sorting a cultured fish group.

[23] An information acquisition step of acquiring information on the amount of at least one organ of a cultured fish group, and a sorting step of sorting the cultured fish group based on the information. A method for culturing fish.

[24] A fish obtained by mating cultured fish sorted by the method for sorting a cultured fish group described in

[22] above.

[25] A fish obtained by mating cultured fish sorted by the method for culturing fish described in

[23] above.

[26] A method for increasing the edible part of a cultured fish by culturing the cultured fish sorted by the method for sorting a cultured fish group described in

[22] above.

[27] A method for increasing the edible part of a cultured fish by culturing a cultured fish belonging to the cultured fish group sorted by the method for culturing fish described in

[23] above.

[0074] The content of the present disclosure will be described in more detail with reference to Examples and Comparative Examples, but the present disclosure is not limited to the following Examples.

[0075] (Example 1: Examination of the correlation between organ weight and FCR) 8 male yellowtails and 8 female yellowtails were obtained on the ocean. One male and one female were selected from these and artificially inseminated to obtain fertilized eggs of 8 families. Each fertilized egg was placed in a breeding tank for each family (Families A to H). The hatched fry were cultured in a separated state for each family. Feeding was carried out by giving a formulated feed for aquaculture mainly composed of fish meal at a full stomach every day. When each fry (cultured fish) grew to approximately the target weight, the cultured fish group for each family was taken out of the breeding tank, anesthetized, and the water was blotted off to measure the total weight (TW １ ) of the cultured fish group for each family. Then, the cultured fish group was returned to the same breeding tank for each family, and the culture was continued.

[0076] When the weight of each cultured fish grew to approximately the next target weight, the cultured fish group for each family was taken out of the breeding tank in the same procedure to measure the total weight (TW ｎ ) of the cultured fish group. After each measurement, the cultured fish group was returned to the same breeding tank for each family, and the culture was continued. The amount of feed given between the (n + 1)-th measurement and the n-th measurement (total feed amount: TF ｋ ) and the total weight (TWｎ＋１ ) and the difference between the total weight of the farmed fish population measured for the nth time (TWn) (ΔTWk = TW ｎ＋１ -TW ｎ From ) the feed efficiency (FCR) is calculated using the following formula (1) ｋ ) was requested. FCR ｋ =TF ｋ / ΔTW ｋ (1)

[0077] Measurements were taken a total of seven times (n=7). The target weights were (30g, 50g, 100g, 200g, 300g, 400g, 500g). After the seventh measurement, the total weight of the farmed fish group and the fork length of each farmed fish were measured. Table 1 shows the average weight and fork length for each family, calculated by dividing the total weight by the number of fish, and the obesity score calculated using formula (2) below. After the seventh measurement, the farmed fish were dissected, and the total weight of the internal organs and the weight of each organ were measured. Table 1 shows the average total weight of the internal organs, the weight of the pyloric caeca, and the weight of the liver for each family. Obesity score = weight (g) / [{fork length (cm)} ３ ] × 1000 (2)

[0078]

[0079] Table 2 shows the mean and standard deviation (σ) for each family of the ratio of total organ weight to body weight (organs / body weight), the ratio of pyloric caeca weight to body weight (pyloric caeca / body weight), and the ratio of liver weight to body weight (liver / body weight). Total body weight (TW) obtained at the 5th measurement. ５ ), total weight obtained in the 6th measurement (TW ６ ), and the amount of feed given between the 5th and 6th measurements (total feed amount: TF5) were used to calculate the FCR using the following formula (3) ５ This is shown in Table 2. Also, the total weight (TW) obtained from the sixth measurement. ６ ), total weight obtained in the 7th measurement (TW ７ ), and the amount of feed given between the 6th and 7th measurements (total feed amount: TF) ６ Using the following formula (4), the FCR ６ This is shown in Table 2. Also, the total body weight (TW) obtained in the first measurement. １ ), total weight obtained in the 7th measurement (TW ７), and the amount of feed given between the first and seventh measurements (total feed amount: TF) ０ Using ), the FCR calculated by the following formula (5) ０ This is shown in Table 2. FCR ５ =TF ５ / (TW ６ -TW ５ ) (3) FCR ６ =TF ６ / (TW ７ -TW ６ ) (4) FCR ０ =TF ０ / (TW ７ -TW １ ) (5)

[0080]

[0081] As shown in Table 2, among families A to H, the FCR of farmed fish populations of families B and G ５ FCR ６ FCR ０ All of these tended to be high. The farmed fish populations of families B and G tended to have a higher ratio of the weight of internal organs and pyloric caeca to body weight than the farmed fish populations of other families. On the other hand, among families A to H, the FCR of farmed fish populations of families C, E, and H ５ FCR ６ FCR ０ All of these tended to be low. The ratio of the weight of internal organs, pyloric caeca, and liver to body weight in farmed fish populations of families C, E, and H tended to be smaller than in farmed fish populations of other families. From these results, it was found that there is a correlation between the total weight of internal organs, the weight of pyloric caeca and liver, and FCR. Furthermore, it was found that a smaller ratio of the total weight of internal organs or the weight of at least one organ to body weight tended to result in a lower FCR.

[0082] Figure 3 shows the FCR calculated using equation (4) ６ This shows the correlation with the ratio of the total weight of internal organs to body weight. Figure 4 shows FCR ６ This shows the correlation with the ratio of pyloric caeca weight to body weight. Figure 5 shows FCR ６This shows a correlation with the ratio of liver weight to body weight. As these figures show, a strong correlation was confirmed in all cases. In particular, a strong correlation was found between FCR and the ratio of total organ weight or pyloric caeca weight to body weight, which can be obtained from farmed fish populations weighing 300g or more.

[0083] (Example 2: Prediction of the weight of at least one organ using an ultrasound device) Ten yellowtail were randomly sampled at sea. Each yellowtail was anesthetized, and its weight and fork length were measured to determine its obesity level using formula (2) above. The results are shown in Table 3. Cross-sectional ultrasound images of the fish were taken using the commercially available ultrasound device shown below. Images were taken at multiple locations. After taking the images, the yellowtail was cut at the locations where the cross-sectional ultrasound images were taken, and the photographs of the cross-sectional ultrasound images were compared with the photographs of the actual cut surface. The fish was also dissected, the pyloric caeca was removed, and its weight was measured using a scale. From the results of the cross-sectional ultrasound images and the measurement of the weight of the pyloric caeca, it was found that there was a strong correlation between the cross-sectional ultrasound image of the base of the pelvic fin and the weight of the pyloric caeca. The cross-sectional area of ​​the pyloric caeca obtained from this cross-sectional ultrasound image and the measured weight of the pyloric caeca are shown in Table 3.

[0084] <Ultrasound Examination Equipment> Model Name: MyLabOne VET Manufacturer: Esaote Europe B. V. (Netherlands) Medical Device Approval Number: 24-Doyaku 2892 Probe: Linear type SV3513 Focal Length: 0-150 mm B-mode Frequency: 6.0, 8.0, 10.0 MHz

[0085]

[0086] Using the data shown in Table 3, the product-moment correlation coefficient between the cross-sectional area of ​​the pyloric caeca obtained from transverse echocardiograms and the measured weight of the pyloric caeca was calculated. The result showed a product-moment correlation coefficient of 0.94. From this result, it was found that the weight of the pyloric caeca can be estimated with high accuracy using the cross-sectional area of ​​the pyloric caeca obtained from echocardiograms.

[0087] (Example 2A) Similar to Example 2, the product-moment correlation coefficient between the cross-sectional area of ​​the pyloric caeca obtained from transverse ultrasound images and the measured weight of the pyloric caeca was calculated for 100 yellowtail weighing 1.3 to 5.3 kg, and was found to be 0.95. The product-moment correlation coefficient between the cross-sectional area of ​​the pyloric caeca obtained from transverse ultrasound images and the measured weight of the pyloric caeca was also calculated for 12 yellowtail weighing 100 g to 200 g, and was found to be 0.95. The product-moment correlation coefficient between the cross-sectional area of ​​the pyloric caeca obtained from transverse ultrasound images and the measured weight of the pyloric caeca was also calculated for 20 individuals weighing 400 g to 800 g, and was found to be 0.89. Even when the weights differ, the product-moment correlation coefficient between the cross-sectional area of ​​the pyloric caeca obtained from transverse ultrasound images and the measured weight of the pyloric caeca is high, so it is possible to calculate a predicted value of the weight of the pyloric caeca from the cross-sectional area of ​​the pyloric caeca obtained from transverse ultrasound images. The predicted weight of the pyloric caeca calculated here can be used as a substitute for the measured weight of the pyloric caeca to calculate its ratio to the weight of farmed fish.

[0088] Similar to the pyloric caeca, it is believed that the cross-sectional area of ​​the liver and other organs can also be determined from transverse ultrasound images. Therefore, by selecting a population of farmed fish with a small cross-sectional area determined by non-destructive testing of at least one organ, or a small weight estimated from that cross-sectional area, it is possible to selectively cultivate farmed fish with a low FCR. Furthermore, it is believed that by crossbreeding farmed fish with low FCRs, it is possible to selectively cultivate fish with low FCRs.

[0089] This disclosure provides a method for selecting fish populations that enable efficient aquaculture, and a method for aquaculture fish. It is possible to provide fish that can be efficiently aquacultured. A fish population with reduced variability in feed efficiency and a package containing such a fish population are provided. A package containing a frozen fish population obtained by aquaculture with reduced variability in feed efficiency is provided. A fish farming facility that enables efficient aquaculture of fish is provided. A method that can efficiently increase the edible portion of aquacultured fish is provided.

[0090] 10... Rearing tank, 11... First rearing tank, 12... Second rearing tank, 20... Inspection device, 21... Non-destructive testing unit, 22... Probe, 24... Control unit, 25... Weight measurement unit, 26... First display unit, 27... Weighing device, 30... Information processing unit, 32... Calculation unit, 34... Second display unit, 50... Fish body, 100... Aquaculture equipment, F0... Aquaculture fish group, F1... First aquaculture fish group, F2... Second aquaculture fish group.

Claims

1. A method for selecting a group of farmed fish, comprising: an information acquisition step of performing non-destructive testing on a group of living farmed fish to obtain information on the quantity of at least one organ; and a selection step of selecting the group of farmed fish based on the information.

2. A method for selecting a group of farmed fish according to claim 1, further comprising a prediction step of predicting the weight of at least one organ based on the information, wherein the selection step is to select the group of farmed fish based on the predicted weight of at least one organ.

3. The method for selecting a group of farmed fish according to claim 2, further comprising a weight measurement step of measuring the weight of each of the farmed fish group, wherein the group of farmed fish is selected based on the ratio of the predicted weight of at least one organ to the weight of each of the farmed fish group.

4. The method for selecting a group of farmed fish according to any one of claims 1 to 3, wherein the selection step involves selecting a group of farmed fish in which each has a weight within a predetermined range.

5. The method for selecting a group of farmed fish according to claim 4, wherein the weight within the predetermined range is 300 g or more.

6. A method for selecting a group of farmed fish according to any one of claims 1 to 3, further comprising a farming step of releasing at least a portion of the group of farmed fish selected in the selection step into a rearing tank for farming.

7. The method for selecting a group of cultured fish according to any one of claims 1 to 3, wherein the information includes the cross-sectional area of ​​at least one organ obtained from cross-sectional images of each of the cultured fish group.

8. The method for sorting a population of cultured fish according to any one of claims 1 to 3, wherein the non-destructive testing includes ultrasonic testing.

9. The method for selecting a group of cultured fish according to any one of claims 1 to 3, wherein the at least one organ includes one or both of the pyloric caeca and the liver.

10. A method for selecting a group of cultured fish according to any one of claims 1 to 3, wherein the group of cultured fish includes marine fish.

11. A method for selecting a group of cultured fish according to any one of claims 1 to 3, wherein the group of cultured fish includes the genus Yellowtail.

12. A method for cultivating fish, comprising the step of selecting at least a portion of a plurality of cultured fish populations selected by the method for selecting cultured fish populations according to any one of claims 1 to 3, in which the ratio of the predicted value of the weight of at least one organ to the body weight of the fish is less than or equal to a predetermined value, to be used as parent fish.

13. A method for cultivating fish, comprising a selection step of selecting broodstock fish from a group of living farmed fish based on information regarding the quantity of at least one organ obtained by non-destructive testing of the group of living farmed fish.

14. A group of farmed fish in which, when the ratio of the weight of the pyloric caeca and the liver to the body weight of the fish is defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals in a single rearing tank is 0.04 or less.

15. A group of farmed fish contained in a container, wherein when the ratio of the weight of the pyloric caeca and the liver to the body weight of the fish is defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals in the group of farmed fish contained in the container is 0.04 or less.

16. A packaging comprising a container and a group of frozen farmed fish contained in the container, wherein, when the ratio of the weight of the pyloric caeca and liver to the body weight of each frozen farmed fish is defined as the pyloric caeca ratio and the liver ratio, respectively, the standard deviation of one or both of the pyloric caeca ratio and the liver ratio for all individuals of the frozen farmed fish contained in the container is 0.04 or less.

17. A fish farming facility comprising: a rearing tank for raising a school of farmed fish; an inspection device for performing non-destructive testing of the surviving school of farmed fish; and an information processing device for deriving information regarding the quantity of at least one organ based on the inspection results obtained by the inspection device.

18. The fish farming apparatus according to claim 17, wherein the inspection apparatus comprises a weight measuring unit for measuring the weight of the farmed fish population, and the information processing device derives a ratio of the weight of the at least one organ to the total weight from the total weight and the weight of the at least one organ predicted based on the inspection results.

19. The fish farming facility according to claim 18, comprising a first rearing tank for raising a first group of farmed fish and a second rearing tank for raising a second group of farmed fish, wherein the average value of the ratio of the first group of farmed fish and the average value of the ratio of the second group of farmed fish are different from each other.

20. A fish obtained by crossbreeding farmed fish selected by the farmed fish group selection method described in any one of claims 1 to 3.

21. A method for increasing the edible portion of farmed fish by farming farmed fish belonging to a group of farmed fish selected by the method for selecting a group of farmed fish according to any one of claims 1 to 3.

22. A method for selecting a group of farmed fish, comprising: an information acquisition step of acquiring information on the quantity of at least one organ of a group of farmed fish; and a selection step of selecting the group of farmed fish based on the information.

23. A method for cultivating fish, comprising: an information acquisition step of acquiring information on the quantity of at least one organ of a group of farmed fish; and a selection step of selecting the group of farmed fish based on the information.

24. A fish obtained by crossbreeding farmed fish selected by the method for selecting a group of farmed fish described in claim 22, or by the method for farming fish described in claim 23.

25. A method for increasing the edible portion of farmed fish belonging to a farmed fish group selected by the method for selecting a farmed fish group according to claim 22, or by the method for farming fish according to claim 23.

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