Ecological ice-temperature low-water-content keep-alive transportation method for Dongpo

Abstract

The invention discloses an ecological ice-temperature low-water-content keep-alive transportation method for Dongpo. The transportation method comprises the following steps: S1, before transportation, carrying out fasting temporary rearing on the Dongmaotai for 18-24 hours; s2, reducing the water temperature in the temporary culture pond from 27-30 DEG C to the transportation temperature of 16-20 DEG C at the cooling speed of 2-3 DEG C / h; s3, fishing out the fishes with weak reaction in the temporary rearing pond, loading the fishes into a packaging bag filled with seawater, filling oxygen and nitrogen for controlled atmosphere, putting the packaging bag into a low-temperature refrigerated transport box, and transporting the fishes under the condition of maintaining the constant temperature of 16-20 DEG C; and S4, transferring the east star spots to a water environment at 16-20 DEG C after keep-alive transportation, and raising the temperature to 28 + / -1 DEG C at a heating rate of 2-3 DEG C / h so as to wake up the east star spots. According to the method, through the methods of temporary rearing, gradient cooling, immersion type less-water packaging, controlled atmosphere oxygenation (oxygen and nitrogen), low-temperature transportation and recovery, the transportation cost of tropical fish east star spots is reduced, the transportation time is prolonged, the survival rate is increased, and good application value and economic benefits are achieved.

Description

Technical Field

[0001] The invention relates to an ecological ice-temperature and water-reduced live-keeping transportation method for grouper, and belongs to the field of marine science and technology. Background Art

[0002] Oriental grouper Plectropomus leopardus ), also known as leopard grouper, spotted grouper, seven-star grouper, etc., belongs to the order Perciformes, family Serranidae, subfamily Epinephelinae, genus Echinops, and is mainly distributed in the tropical waters of the Indian and Pacific Oceans, and is distributed on the east coast and southern waters of Hainan Province. Grouper is rich in nutrients, tender and delicious, with the characteristics of high protein, low fat and low cholesterol. It has high economic value, and because of its bright colors and good ornamental value, it is deeply favored by consumers and has broad market prospects. However, due to the large span of production and sales areas, the lack of sophisticated survival technology and the imperfect configuration of transportation equipment, the high transportation cost of grouper and the high loss rate of long-distance transportation have greatly restricted the development of the sales market of grouper.

[0003] The eastern star grouper usually lives in a relatively stable and warm environment, with an adaptability range of 25-30℃. Compared with temperate and cold zone aquatic animals, the eastern star grouper usually has a higher metabolic rate. At the same time, the eastern star grouper is more dependent on high dissolved oxygen content, especially in a high temperature environment, where oxygen consumption is high. They are also sensitive to changes in water quality and are easily affected by pollution. During the live transportation process, the unique physiological characteristics of the eastern star grouper (temperature adaptability, high metabolic rate, water quality sensitivity) have an important impact on the survival rate of transportation.

[0004] There are three basic transportation systems for live fish trade, namely closed system, open or water tank method and improved waterless system. The open transportation system needs to carry a large amount of oxygen and power supply equipment, which has a high transportation cost. At the same time, the open oxygen supply is easy to contact the outside world, causing water pollution, resulting in a high loss rate during fish transportation. The use of single closed packaging for fresh fish logistics transportation can save space, reduce costs and ensure quality. However, there are also several difficulties in closed packaging transportation. Fish have a certain tolerance range for oxygen concentration. Excessive oxygen concentration can cause metabolic disorders in fish, and problems such as breathing difficulties and gill damage occur. Conversely, if the fish consumes oxygen too quickly in a closed environment, the oxygen concentration in the water will drop rapidly, leading to hypoxia. Hypoxia can cause serious consequences such as suffocation, stress and death of fish. In addition, in closed water-less transportation, less water will cause a sharp increase in the concentration of harmful substances (such as ammonia nitrogen and sulfide), which will stimulate the respiratory system and other physiological functions of fish and accelerate the death of fish. At the same time, the fish body may be exposed to the air, causing dry gills and skin, which will cause damage. This physical damage will further increase the stress response of fish and affect their physiological state. The deterioration of water quality caused by fish stress is the main factor restricting fish transportation. The stress response caused by water quality changes during transportation includes disorders of metabolic system and immune function, liver tissue damage, etc.

[0005] Patent application CN117530226A discloses a method for transporting cold-water fish without water, which involves temporarily stopping feeding of the cold-water fish, precooling at low temperature, and transporting them in a sealed and oxygenated manner, thereby extending the transportation time and improving the survival rate of the transport. However, the method is only applicable to the transportation of cold-water fish without water, and is not applicable to the transportation of fish from the south to the north. Patent application CN17958183A discloses a method for transporting turbot without water at an ecological ice temperature, wherein turbot undergoes temporary rearing, gradient cooling, oxygenation, low-temperature transportation, and recovery, thereby extending the waterless transportation time and improving the survival rate. However, the method is not applicable to tropical fish with high metabolic rate, water quality sensitivity, and low-temperature intolerance, and has a relatively small application range. Patent application CN113994902B discloses a method for transporting golden pomfret without water, wherein the golden pomfret is temporarily reared, anesthetized with clove essential oil, added to a sealed bag, and vitamin C protective solution is added at the same time, and transported with oxygen, thereby increasing the loading capacity, extending the transportation time, and improving the survival rate. However, the safety of clove essential oil needs further study. Patent application CN103688898B discloses a novel method for transporting fish without water, which uses carbon monoxide-nitrogen method to put live fish into hibernation, and combines pressure with modified atmosphere packaging to keep the fish alive for transportation, thereby increasing the survival rate and survival time of the fish. However, carbon monoxide is toxic, and its safety needs further exploration. The present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide an ecological ice-temperature and low-water survival transportation method for grouper, which alleviates the stress response and tissue damage of grouper during low-water transportation, improves the survival rate of low-water transportation, and saves transportation costs.

[0007] The ecological ice-temperature and water-saving alive transportation method of grouper provided by the present invention comprises the following steps: S1. Fast the grouper for 18-24 hours before transportation; S2. Reduce the water temperature in the temporary holding pond from 27-30°C to the transportation temperature of 16-20°C at a rate of 2-3°C / h; S3, fish with weak touch reaction in the temporary holding pond are removed, placed in a packaging bag filled with seawater, filled with oxygen and nitrogen, placed in a low-temperature refrigerated transport box, and transported at a constant temperature of 16-20°C; S4. After being transported alive, the grouper is moved to a water environment at 16-20°C, and the temperature is raised to 28°C at a rate of 2-3°C / h to wake up the grouper.

[0008] The grouper should be healthy, weigh 0.5-0.75kg and have a consistent breathing rate.

[0009] In the ecological ice-temperature and low-water live transportation method of the present invention, in step S1, the temporary maintenance conditions are as follows: The water temperature is 28℃, the salinity is 30-35, the dissolved oxygen is 6-7 mg / L, the pH is 7.8-9.0, and the fish-water ratio is 1:30-50.

[0010] In the ecological ice temperature and low water preservation and transportation method of the present invention, in step S3, the fish-water ratio in the packaging bag is 1:1-2; The length-to-width ratio of the packaging bag is 45-55:30-40. The packaging bag is sealed at a height of 1 / 3-1 / 2 by a heat sealer, and the heat seal length is 1 / 2-3 / 4 of the total length. The seal divides the packaging bag into an upper layer and a lower layer, the lower layer is filled with fish and water, and the upper layer is filled with gas.

[0011] The transport temperature is 16-20°C, preferably 18°C The composition of the gas filled in the packaging bag is: 65%-100% oxygen, 0%-35% nitrogen, preferably 85% oxygen, 15% nitrogen; In the ecological ice-temperature and low-water live transport method of the present invention, a one-way valve is provided in the live fish oxygenation transport bag for inflating the packaging bag to achieve one-way flow of gas during the inflation process, thereby ensuring that the composition ratio of the gas components remains unchanged.

[0012] As a kind of precious edible fish, grouper is of high value, and the value of fresh grouper is twice that of frozen grouper. The method of the present invention fully saves transportation costs. The fish-water ratio of grouper in the market is usually 1:3-5. The present invention reduces the fish-water ratio of grouper to 1:1, increases the transportation load by 3-5 times, and ensures its transportation time and quality at the same time, effectively reduces transportation costs, and obtains higher economic benefits. The method of the present invention adopts closed packaging for oxygenation, and there is no need to carry a large amount of oxygen supply and power supply equipment, which reduces transportation weight, saves space, and reduces costs.

[0013] The methods of temporary culture, gradient cooling, immersion low-water packaging, controlled atmosphere oxygenation (oxygen and nitrogen), low-temperature transportation, and recovery provided by the present invention can effectively reduce the energy consumption and metabolic rate of grouper during the alive transportation process, and regulate the changes in serum cortisol and liver metabolic enzymes of grouper caused by stress.

[0014] The present invention reduces the transportation cost of tropical fish grouper, prolongs the transportation time and improves the survival rate through temporary culture, gradient cooling, immersion-type low-water packaging, atmosphere-controlled oxygenation (oxygen and nitrogen), low-temperature transportation and recovery methods, and has good application value and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the packaging used in the transportation method of the present invention.

[0016] Figure 2 Schematic diagram of packaging used for existing transportation methods.

[0017] Figure 3 Changes in serum cortisol levels after 6 hours of transportation using different packaging methods.

[0018] Figure 4 Changes of superoxide dismutase (SOD) activity in serum after 6 hours of transportation in different packaging methods.

[0019] Figure 5 The survival time and survival rate of grouper with different water-reducing transportation methods.

[0020] Figure 6 Changes in serum cortisol content in grouper at different transportation temperatures under immersed modified atmosphere packaging.

[0021] Figure 7 The content of heat shock protein (HSP-70) in Ornithogalum truncatum under immersed modified atmosphere packaging at different transportation temperatures.

[0022] Figure 8 This is a function graph of the survival rate of grouper transported at 18℃ under different atmosphere conditioning ratios. DETAILED DESCRIPTION

[0023] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0024] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0025] Example 1: Effects of different packaging methods on the water-poor transportation of grouper (1) Select healthy groupers with a weight of 0.5 kg and a consistent respiratory rate. Fast them for 24 hours before transportation. During the fasting period, the water temperature is 28°C, the salinity is 35, the dissolved oxygen is 7 mg / L, the pH is 9, and the fish-water ratio is 1:50. During the fasting period, metabolic waste in the groupers is discharged.

[0026] (2) Use ecological ice temperature and less water to keep the animals alive during transportation: Set up a fully automatic circulating refrigeration machine to cool the water in the temporary storage pool from 28°C to the transportation temperature of 20°C at a cooling rate of 2°C / h, and temporarily store the animals at 20°C for 2 hours.

[0027] (3) In this experiment, the grouper was divided into three groups: a control group (not transported), a conventional low-water packaging and transportation group, and an immersion low-water packaging and transportation group.

[0028] Conventional low-water packaging and transportation group: fish with very weak touch reactions in the temporary holding box are taken out and packed into a sealing bag with a ratio of seawater to grouper of 1:1. Then pure oxygen is filled in and placed in a low-temperature refrigerated transportation box, and the box is maintained at a constant temperature of 20°C. Conventional packaging methods include Figure 2 As shown, the packaging bag expands during the oxygenation process, causing the water level to drop and the body of the grouper fish to be exposed to the air.

[0029] Immersed low-water packaging and transportation group: fish with very weak touch reactions in the temporary holding box are taken out and quickly placed in a special packaging bag filled with seawater, with the ratio of seawater to grouper being 1:1. Then pure oxygen is filled in and placed in a low-temperature refrigerated transportation box, with the box maintained at a constant temperature of 20°C. Figure 1 As shown. The length-to-width ratio of the packaging bag used is 45:30. The packaging bag is sealed at 1 / 3 of the height by a heat sealer, and the heat seal length is 1 / 2 of the total length. The seal divides the packaging bag into an upper layer and a lower layer. The lower layer is filled with fish and water, and the upper layer is filled with gas. Immersed low-water packaging reduces air exposure of the fish while ensuring dissolved oxygen in the water.

[0030] (4) Refrigerated transportation: The temperature of the transport box is maintained at 20°C during transportation; (5) Wake-up: After keeping the grouper alive, move it to a 20°C water environment and raise the temperature to 28°C at a rate of 2°C / h.

[0031] The levels of cortisol and superoxide dismutase (SOD) in the blood biochemical indicators of grouper in different transportation groups and control group after transportation Figure 4 and Figure 5 As shown. Monitoring the changes in cortisol during transportation can provide important information for assessing the health status and transportation conditions of fish. High levels of cortisol usually mean that the fish are in a state of high stress. Superoxide dismutase (SOD) is an important antioxidant enzyme that is mainly responsible for removing superoxide free radicals in cells and protecting cells from oxidative damage. During the transportation of fish, the changes in SOD can reflect the physiological state and stress response of fish. After 6 hours of transportation, the conventional low-water packaging group produced a significant stress response due to the air exposure of the fish body, and the cortisol content and SOD activity in the blood increased significantly compared with the control group. However, the cortisol content in the blood of the transportation group that was transported by immersion low-water packaging was not significantly different from that of the control group, indicating that this packaging method helps to reduce the stress response of fish during transportation, ensure the vitality of fish during transportation, and prolong survival time.

[0032] Example 2: Effects of different temperatures, packaging and transportation methods on the survival rate of grouper (1) Select healthy groupers with a weight of 0.75 kg and consistent respiratory rate. Fasting and temporary storage for 24 hours before transportation. During the temporary storage period, the water temperature was 28℃, salinity was 30, dissolved oxygen was 6 mg / L, pH was 7.8, and the fish-water ratio was 1:30. During the fasting and temporary storage period, metabolic waste in the body of the groupers was discharged. The groupers were divided into two groups, namely the ecological ice temperature immersion low water packaging transportation group and the normal temperature conventional low water packaging transportation group.

[0033] (2) Cool down the fish in the ecological ice temperature immersion and low-water packaging and transportation group: set the fully automatic circulating refrigerator to cool down the water temperature in the temporary holding pond from 28°C to the transportation temperature of 18°C ​​at a cooling rate of 3°C / h, and temporarily hold the fish at 18°C ​​for 2 hours. The metabolic rate of the grouper was effectively reduced under low temperature conditions.

[0034] (3) Ecological ice temperature immersion low water packaging and transportation group packaging: Take out the fish with very weak touch reaction in the temporary storage box, quickly put them into a sealing bag filled with seawater, the ratio of seawater to grouper is 1:2, then fill it with oxygen, put it into a low temperature refrigerated transportation box, and maintain a constant temperature of 18℃ in the box. Figure 1 As shown. The length-to-width ratio of the packaging bag used is 55:40. The packaging bag is sealed at 3 / 4 of the height by a heat sealer, and the heat seal length is 1 / 2 of the total length. The seal divides the packaging bag into an upper layer and a lower layer. The lower layer contains fish and water, and the upper layer is filled with gas. Immersed low-water packaging reduces the air exposure of the fish while ensuring the dissolved oxygen in the water.

[0035] Normal temperature conventional low water packaging and transportation group: without gradient cooling, the grouper is packaged in a sealing bag with a ratio of seawater to grouper of 1:2, then filled with pure oxygen and transported at room temperature of 18°C. Conventional packaging methods are as follows: Figure 2 As shown, the packaging bag expands during the oxygenation process, causing the water level to drop and the body of the grouper fish to be exposed to the air.

[0036] (4) Transportation temperature: The temperature of the transport box of the ecological ice temperature immersion low-water packaging and transportation group is maintained at 18°C ​​during packaging and transportation, and the room temperature of the normal temperature conventional low-water packaging and transportation group is 25°C during room temperature transportation.

[0037] (5) Awakening: After the ecological ice temperature immersion and low water packaging and transportation group was kept alive with low water, the grouper was moved to an 18℃ water environment and heated to 28℃ at a rate of 3℃ / h. The test results of the survival rate and survival time of the grouper in the live transportation are as follows: Figure 5 shown.

[0038] Depend on Figure 5 It can be seen that the survival time of the grouper in the normal temperature conventional low-water packaging and transportation group is only 4 hours, and the survival rate gradually decreases. The ecological ice temperature immersion low-water packaging and transportation group can ensure that the survival rate reaches 100% after 12 hours of transportation.

[0039] Example 3: Effects of serum cortisol and heat shock protein HSP-70 during the transportation of grouper in ecological ice-temperature immersion and low-water packaging Cortisol plays a key role in fish's response to external stress and physiological regulation. Cortisol is mainly synthesized in the adrenal glands (or the equivalent of adrenal cells in fish). When fish are stressed, cortisol levels increase. This is an important part of the stress response in fish, which helps them quickly adapt to environmental changes. Cortisol drives the body to cope with challenges by increasing energy supply (such as by increasing blood sugar and fatty acid release). Moderate cortisol release helps fish adapt to adverse environments, while chronic high levels may have a negative impact on growth and fertility. Due to the role of cortisol in stress response, monitoring cortisol levels in fish has been widely used in ecological and aquaculture studies. By measuring cortisol levels, the stress state of fish under different environmental conditions can be assessed.

[0040] Physical stress during transportation (such as handling, hypoxia, crowding, etc.) can cause a series of changes in the metabolism, endocrine system and immune system of fish. As a cell protection protein, HSP70 can be rapidly synthesized under stress conditions to help proteins fold, assemble and transport correctly, while regulating and repairing damaged proteins and degrading denatured proteins. HSP70 plays an important role in stress response, gene expression regulation, changes in physiological and biochemical indicators, antioxidant defense system and immune regulation during fish transportation, and is one of the key proteins for fish to cope with transportation stress.

[0041] Grouping and processing of grouper for transportation: (1) Select healthy groupers with a weight of 0.5-0.75 kg and a consistent respiratory rate. Fast them for 18 hours before transportation. During the fasting period, the water temperature is 28°C, the salinity is 32, the dissolved oxygen is 6.5 mg / L, the pH is 8, and the fish-water ratio is 1:40. During the fasting period, metabolic waste in the groupers is discharged.

[0042] (2) The ecological ice temperature and low water preservation transportation method was used to cool down the fish: a fully automatic circulating refrigerator was set up to cool down the water in the temporary holding pond from 28°C to 16°C, 18°C, 20°C, and 22°C, respectively, at a cooling rate of 2°C / h. The metabolic rate of the grouper was effectively reduced under low temperature conditions.

[0043] (3) Ecological ice temperature and low water keep-alive transportation packaging method: Take out the fish with very weak touch reaction in the temporary holding box, and quickly put them into a packaging bag filled with seawater. The ratio of seawater to grouper is 1:1. Then fill it with 85% oxygen and 15% nitrogen, and put it into a low-temperature refrigerated transportation box. Maintain a constant temperature of 16℃, 18℃, 20℃, or 22℃ in the box.

[0044] (4) Ecological ice temperature and low water preservation transportation method Refrigerated transportation: The temperature of the transport box is maintained at 16℃, 18℃, 20℃, and 22℃ during transportation.

[0045] (5) Awakening: After keeping the grouper alive without water, move it to a water environment at 16℃, 18℃, 20℃, or 22℃, and raise the temperature to 28℃ at a rate of 2℃ / h.

[0046] ELISA for detection of cortisol in fish serum: (1) Select anti-cortisol antibodies with high affinity and specificity; Cortisol standards are used to prepare the standard curve.

[0047] (2) Serum samples extracted from fish.

[0048] (3) Dilute the anti-cortisol antibody and add it to the wells of the ELISA plate, covering the entire well surface, usually overnight at 4°C. Wash the plate several times with a wash buffer (PBS buffer plus Tween-20). Add a blocking solution (such as bovine serum albumin BSA or skim milk powder) to the wells and incubate at room temperature to reduce nonspecific binding. Dilute the fish serum sample to an appropriate concentration, then add the sample and cortisol standards to different wells and incubate at room temperature for a period of time. After incubation, wash to remove unbound substances. Add the detection antibody, which is specific for cortisol, and incubate at room temperature. Wash again to remove unbound antibodies. Add the enzyme substrate and react in the dark. Use a microplate reader to measure the light absorbance (OD value) at a specific wavelength (450 nm). Draw a standard curve based on the OD value of the cortisol standard to calculate the concentration of cortisol in the sample.

[0049] like Figure 6 As shown, during the 12h transportation, the content of cortisol in the serum of grouper was lowest when transported at 18℃. The results showed that grouper, as a hot water fish, was more sensitive to temperature. When transported at 18℃, grouper was least affected by stress, which was beneficial to reducing its metabolism and maintaining its life activities through low-temperature hibernation.

[0050] Detection of heat shock protein HSP-70 in fish serum using ELISA: (1) Selecting an anti-heat shock protein HSP-70 antibody with high affinity and specificity; heat shock protein HSP-70 standard for preparing a standard curve.

[0051] (2) Serum samples extracted from fish.

[0052] (3) Add anti-HSP-70 antibody to the wells of the ELISA plate after dilution, covering the entire well surface, usually overnight at 4°C. Wash the plate several times with washing solution (PBS buffer plus Tween-20). Add blocking solution (such as bovine serum albumin BSA or skim milk powder) to the wells and incubate at room temperature to reduce nonspecific binding. Dilute the fish serum sample to an appropriate concentration, then add the sample and HSP-70 standard to different wells and incubate at room temperature for a period of time. After incubation, wash to remove unbound substances. Add detection antibody, which is specific for HSP-70, and incubate at room temperature. Wash again to remove unbound antibodies. Add enzyme substrate and react under light-protected conditions. Use an ELISA reader to measure the light absorbance (OD value) at a specific wavelength (450 nm). Draw a standard curve based on the OD value of the HSP-70 standard to calculate the concentration of HSP-70 in the sample.

[0053] like Figure 7 As shown in the figure, with the extension of the live transport time, the content of heat shock protein HSP-70 in the serum of the eastern star grouper showed a gradual increase trend, which indicates that the degree of oxidative stress is increasing with the extension of the live transport time. When the temperature is too low (16°C), the content of heat shock protein HSP-70 is significantly higher than that of other groups, indicating that too low temperature will cause cold stress to the eastern star grouper. Therefore, on the whole, the optimal temperature range is 18°C.

[0054] Example 4: Effects of different oxygen concentration ratios on low-temperature transportation of packaged grouper During transportation, the respiratory rate and physiological metabolism of fish will be affected. Changes in dissolved oxygen content will affect the respiratory rate and physiological metabolism of fish, and thus affect their life activities. Under hypoxic conditions, a large number of active free radicals will be produced in the body of fish, inducing oxidative stress reactions, destroying body cells and tissues, leading to decreased immunity and even death. CO produced by respiration 2 In fish, it exists in the form of physical dissolution, HCO3-, and binding to hemoglobin, and is transported to the gills through the blood and then diffused into the water. 2 The accumulation of oxygen will affect the acid-base balance of the blood, and then affect the respiration and metabolism of fish. Therefore, by adjusting the oxygen gas in different proportions, the dissolved oxygen in the water is regulated, and then the respiration and metabolism of the grouper during transportation are regulated to maintain the balance of the water environment.

[0055] Grouping and processing of grouper for transportation: (1) Select healthy groupers with a weight of 0.5-0.75 kg and a consistent respiratory rate. Fast them for 24 hours before transportation. During the fasting period, the water temperature is 28°C, the salinity is 35, the dissolved oxygen is 7 mg / L, the pH is 7.8, and the fish-water ratio is 1:50. During the fasting period, metabolic waste in the groupers is discharged.

[0056] (2) The ecological ice temperature and low water preservation transportation method was used to cool down the fish: a fully automatic circulating refrigerator was set to cool down the water temperature in the temporary holding pond from 28°C to the transportation temperature of 18°C ​​at a cooling rate of 2°C / h, and the fish were temporarily held at this temperature for 2 hours. The metabolic rate of the grouper was effectively reduced under low temperature conditions.

[0057] (3) Ecological ice temperature and low water keep-alive transportation packaging method: Take out the fish with very weak touch reaction in the temporary holding box and quickly put them into a sealing bag filled with seawater. The ratio of seawater to grouper is 1:1. Then divide them into 4 groups and fill them with 100% oxygen, 85% oxygen and 15% nitrogen, 75% oxygen and 25% nitrogen, and 65% oxygen and 35% nitrogen respectively. Put them into a low-temperature refrigerated transportation box and maintain a constant temperature of 18°C ​​in the box.

[0058] (4) Ecological ice temperature and low water preservation transportation method Refrigerated transportation: The temperature of the transport box is maintained at 18℃ during transportation.

[0059] (5) Awakening: After keeping the fish alive without water, move the grouper to an 18°C ​​water environment and heat it to 28°C at a rate of 2°C / h.

[0060] The results are as follows Figure 8 As shown in the figure, the survival rate function graph shows that the 12-hour transportation survival rate can reach 100% under the ratio of 85% oxygen and 15% nitrogen, indicating that the controlled atmosphere controlling the oxygen pressure difference has an obvious effect on regulating the respiratory metabolism of the eastern star grouper and maintaining the stability of respiratory metabolism.

[0061] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. An ecological ice-temperature and water-saving method for transporting grouper, comprising the following steps: S1. Fast the grouper for 18-24 hours before transportation; S2. Reduce the water temperature in the temporary holding pond from 28°C to the transportation temperature of 16-20°C at a rate of 2-3°C / h; S3, fish with weak touch reaction in the temporary holding pond are removed, placed in a packaging bag filled with seawater, filled with oxygen and nitrogen, placed in a low-temperature refrigerated transport box, and transported at a constant temperature of 16-20°C; S4. After being transported alive, the grouper is moved to a water environment at 16-20°C, and the temperature is raised to 28°C at a rate of 2-3°C / h to wake up the grouper.

2. The ecological ice temperature and low water preservation and transportation method according to claim 1 is characterized in that: In step S1, the temporary maintenance conditions are as follows: The water temperature is 28℃, the salinity is 30-35, the dissolved oxygen is 6-7 mg / L, the pH is 7.8-9.0, and the fish-water ratio is 1:30-50.

3. The ecological ice temperature and low water preservation transportation method according to claim 1 or 2, characterized in that: The grouper should be healthy, weigh 0.5-0.75kg and have a consistent breathing rate.

4. The ecological ice temperature and low water preservation transportation method according to claim 1 or 2, characterized in that: In step S3, the fish-water ratio in the packaging bag is 1:1-2.

5. The ecological ice temperature and low water preservation transportation method according to claim 1 or 2, characterized in that: In step S3, the packaging bag has a length-to-width ratio of 45-55:30-40, and the packaging bag is sealed at a height of 1 / 3-1 / 2 by a heat sealer, and the heat seal length is 1 / 2-3 / 4 of the total length; the sealing divides the packaging bag into an upper layer and a lower layer, the lower layer is filled with fish and water, and the upper layer is filled with gas.

6. The ecological ice temperature and low water preservation and transportation method according to claim 1 or 2, characterized in that: In step S3, the gas composition in the packaging bag is: 65%-100% oxygen and 0%-35% nitrogen.

7. The ecological ice-temperature and low-water transportation method according to claim 1 or 2, characterized in that: The live fish oxygenated transport bag for inflating the packaging bag is provided with a one-way valve to achieve one-way flow of gas during the inflation process.

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