A method for testing povidone-iodine stress of white shrimp fry

Abstract

The present application provides a method for testing povidone-iodine stress of white shrimp fry, which reflects the stress resistance of shrimp fry by measuring the survival rate of povidone-iodine stress of white shrimp fry, and also reflects the disease resistance of shrimp fry, providing data basis for the selection and cultivation of shrimp fry, solving the problem of lack of testing of the chemical and environmental stress resistance of shrimp fry at various stages in the prior art, providing a basis for hatcheries to judge the disease resistance and stress resistance of shrimp fry, and the screened shrimp fry can reduce the stress response caused by environmental changes during transportation, which is an effective means to judge the stress resistance quality of white shrimp fry at various developmental stages.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to a povidone-iodine stress test method for white shrimp fry. Background Art

[0002] As the scale of shrimp farming continues to increase, the demand for shrimp seedlings is increasing. The quality of seedlings has always been the most concerned issue for farmers, which will affect the survival rate of subsequent farming. Therefore, how to choose seedlings has become the primary issue for farmers and a difficult problem. There are many methods to judge the quality of shrimp seedlings, such as observing the liver and pancreas, intestines, and body surface of shrimp seedlings under a microscope, and calculating the growth rate of shrimp seedlings by measuring body length. The stress resistance of shrimp seedlings is directly related to disease resistance. However, farmers lack more accurate tests on the disease resistance of shrimp seedlings at different stages.

[0003] Chinese patent application number (CN201811498610.3) discloses a method for evaluating the stress resistance of white shrimp fry. The survival rate of shrimp fry is calculated by the difference in water salinity to reflect the difference in seedling quality. However, there are many interferences and it is not accurate enough. It can only reflect the shrimp fry's ability to resist desalination, but cannot reflect the shrimp fry's ability to resist chemical, environmental and other stresses.

[0004] Therefore, there is an urgent need for a method that can effectively and accurately test the stress resistance of white shrimp fry so that farmers can effectively judge the quality of shrimp fry. Summary of the invention

[0005] The invention aims to solve the technical problems that the stress resistance test in the prior art has many interferences and is not accurate enough, and mainly uses desalination stress as the main means, which reflects the desalination resistance of shrimp fry but cannot reflect the resistance of shrimp fry to chemical, environmental and other stresses. A povidone-iodine stress test method for white shrimp fry is provided.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for testing povidone-iodine stress of white shrimp fry comprises the following steps:

[0008] S1. Prepare stress test adaptogen;

[0009] S2. Place a certain proportion of shrimp seedlings into container A filled with original pond water, and add the stress test adaptogen prepared in step S1 into container A, and keep it inflated;

[0010] S3, take out 1 / 5-3 / 5 of the healthy shrimp seedlings in the container A after being inflated in step S2, and put them into the container B containing the original pond water containing povidone iodine, keep it inflated and avoid light;

[0011] S4, take out the shrimp fry in the aerated container B in step S3, put it into the container C filled with only the original pond water and aerate it for 30 minutes. After the aeration is completed, the shrimp fry are divided into two groups according to the development stage PL N (N represents the value of the shrimp fry development stage), calculate the stress survival rate of the shrimp fry and judge the quality of the shrimp fry;

[0012] S5. The formula for calculating stress survival rate is: stress survival rate % = 100 × (total number of shrimp seedlings - number of dead seedlings) / total number of shrimp seedlings;

[0013] S6. Evaluation criteria: Setting the PL of shrimp fry development stage 4-9 The survival rate of 90% is the standard survival rate of shrimp fry, and the survival rate of shrimp fry development stage PL is set 10 or PL 10 The above survival rate of 93% is the standard survival rate of shrimp fry.

[0014] Preferably, the stress test adaptor comprises the following components by weight: 2-7 parts of glutathione, 30-80 parts of astragalus polysaccharide, 20-30 parts of vitamin C phosphate, 30-80 parts of water and 0.5-1.5 parts of surfactant. By adding a surfactant to the stress test adaptor, the absorption rate of glutathione and vitamin C phosphate by shrimp seedlings can be improved, and the stress test adaptor can be dispersed faster in the original pond water through the surfactant and inflation to ensure the stability of the anti-stress test.

[0015] Preferably, the surfactant is any one of sodium lauroyl glutamate, sodium dodecylbenzene sulfonate and sorbitan monostearate.

[0016] Preferably, the inflation time in step S2 is 12-14 hours.

[0017] Preferably, the developmental stage in step S2 is PL 4-9 The shrimp seed placement ratio is 1:120-140 liters / tail, and the development stage is PL 10 or PL 10 The above shrimp seed placement ratio is 1:90-115 liters / tail. By setting the ratio of the original pond water volume in the container to the number of standard thick shrimp seed placed at different periods, the development stage is set as PL 4-9 The shrimp seed placement ratio is 1:120-140 liters / tail, and the development stage is set to PL 10 or PL 10 The above shrimp fry placement ratio is 1:90-115 liters / tail, which can ensure the stability of the experiment and make the shrimp fry at different stages evenly distributed in the container. Since the standard coarse shrimp fry at different stages have great differences in body shape, the high density in the water body can easily lead to the fry competing for food with each other.

[0018] Preferably, the inflation time in step S3 is 30-40 minutes.

[0019] Preferably, the effective content of povidone iodine in step S3 is ≥99%, the effective iodine content is 10%, the povidone iodine concentration in the original pond water is 400-600 ppm, and more preferably, the povidone iodine concentration in the original pond water is 500 ppm.

[0020] Preferably, the dead shrimps include shrimps that sink to the bottom and die, shrimps that lie on their sides, shrimps that can swim or swim intermittently and twitch, and shrimps that swim in circles.

[0021] Preferably, if the shrimp fry development stage PL calculated in step S5 is 4-9 If the survival rate is greater than 90%, the PL 4-9 The shrimp fry at this stage have better stress resistance quality;

[0022] If the calculated shrimp fry development stage PL 10 If the survival rate is greater than 93%, the PL 10 or PL 10 The shrimp fry in the above stages have better stress resistance.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] The present application provides a method for testing povidone-iodine stress of white shrimp fry, which reflects the stress resistance of shrimp fry by measuring the survival rate of povidone-iodine stress of white shrimp fry, and also reflects the disease resistance of shrimp fry, providing data basis for the selection and cultivation of shrimp fry, solving the problem of lack of testing of the chemical and environmental stress resistance of shrimp fry at various stages in the prior art, providing a basis for hatcheries to judge the disease resistance and stress resistance of shrimp fry, and the screened shrimp fry can reduce the stress response caused by environmental changes during transportation, which is an effective means to judge the stress resistance quality of white shrimp fry at various developmental stages. DETAILED DESCRIPTION

[0025] The specific technical scheme of the present invention is described below in conjunction with specific embodiments 1-3:

[0026] Embodiment 1:

[0027] A hatchery conducted a povidone-iodine stress test on shrimp seedlings at the PL8 development stage in ponds 1-4 in workshop A.

[0028] 1) Prepare a stress test adaptogen by adding 5 parts of glutathione, 50 parts of astragalus polysaccharide, 25 parts of vitamin C phosphate and 1.5 parts of sodium lauroyl glutamate to 50 parts of water, and stir and mix well;

[0029] 2) Place 4 L of original shrimp seedling culture pond water in container A, take 500 standard thick shrimp seedlings at the PL8 developmental stage and place them in container A, add stress test adaptogen, and keep it inflated;

[0030] 3) After 12 hours, take about 200 healthy shrimp fry from container A and place them into container B containing 500 ppm povidone-iodine original pond water;

[0031] 4) Keep the temperature of container B at 29-30°C, keep it in a dark environment and avoid light, and put in an air stone to inflate for 30 minutes;

[0032] 5) Take out the shrimp fry and put them into a small bucket with only the original pond water and aerate for 30 minutes;

[0033] 6) After the time is up, use a small spoon to count the shrimp fry, including the total number of shrimp fry and the number of dead shrimp fry;

[0034] 7) The stress survival rate was calculated. The results are shown in Table 1.

[0035] Table 1: Povidone-iodine stress test results of shrimp seedlings in pools 1-4 in workshop A of a certain hatchery

[0036]

[0037] It can be seen from the test results in Table 1 that the quality of shrimp fry tested in different pools of the same workshop, strain and same developmental stage PL8 is different. It is difficult to distinguish the quality of shrimp fry only by naked eye observation or microscopic examination, and the anti-desalination test in the prior art is difficult to distinguish the true stress resistance of shrimp fry. The povidone-iodine anti-stress test method for shrimp fry of the present invention provides an effective reference for farmers to judge the quality of shrimp fry.

[0038] Embodiment 2:

[0039] PL of No. 1-6 pools in workshop B of a standard roughing plant 13 The shrimp fry at the developmental stage were subjected to povidone-iodine stress test.

[0040] 1) Prepare a stress test adaptogen by adding 7 parts of glutathione, 80 parts of astragalus polysaccharide, 20 parts of vitamin C phosphate and 1 part of sodium dodecylbenzene sulfonate to 50 parts of water, and stir and mix well;

[0041] 2) Place 10L of original shrimp culture pond water in container A and take 900 PL 13 Put the standard thick shrimp fry in the development stage into container A, add the stress test adaptogen, and keep it inflated;

[0042] 3) After 12 hours, about 180 healthy shrimp fry were taken from container A and placed in container B containing 500 ppm of original pond water containing povidone iodine;

[0043] 4) Keep the temperature of container B at 29-30°C, keep it in a dark environment and avoid light, and put in an air stone to inflate for 30 minutes;

[0044] 5) Take out the shrimp fry and put them into a small bucket with only the original pond water and aerate for 30 minutes;

[0045] 6) After the time is up, use a small spoon to count the shrimp fry, including the total number of shrimp fry and the number of dead shrimp fry;

[0046] 7) The stress survival rate was calculated. The results are shown in Table 2.

[0047] Table 2: Povidone-iodine stress test results of shrimp seedlings in pools 1-6 of workshop B of a certain standard crude farm

[0048]

[0049] From the test results in Table 2, it can be seen that the same workshop, strain and the same development stage are PL 13 The quality of shrimp fry tested in different ponds is also different. It is difficult to distinguish the quality of shrimp fry only by naked eye observation or microscopic examination, and the anti-desalination test in the prior art is difficult to distinguish the true stress resistance of shrimp fry. The povidone-iodine anti-stress test method for shrimp fry of the present invention provides an effective reference for farmers to judge the quality of shrimp fry.

[0050] Embodiment 3:

[0051] A certain standard farm conducted a povidone-iodine stress test on shrimp seedlings at the PL4 development stage in ponds 1-5 of workshop C.

[0052] 1) Prepare a stress test adaptogen by adding 2 parts of glutathione, 50 parts of astragalus polysaccharide, 20 parts of vitamin C phosphate and 0.5 parts of sorbitan monostearate to 50 parts of water, and stir and mix well;

[0053] 2) Place 5L of shrimp seedling culture pond water in container A, take 600 PL4 developmental stage standard thick shrimp seedlings and place them in container A, add stress test adaptogen, and keep it inflated;

[0054] 3) After 12 hours, about 160 healthy shrimp fry were taken from container A and placed in container B containing 500 ppm of original pond water containing povidone iodine;

[0055] 4) Keep the temperature of container B at 29-30°C, keep it in a dark environment and avoid light, and put in an air stone to inflate for 30 minutes;

[0056] 5) Take out the shrimp fry and put them into a small bucket with only the original pond water and aerate for 30 minutes;

[0057] 6) After the time is up, use a small spoon to count the shrimp fry, including the total number of shrimp fry and the number of dead shrimp fry;

[0058] 7) The stress survival rate was calculated. The results are shown in Table 3.

[0059] Table 3: Povidone-iodine stress resistance test results of shrimp seedlings in pools 1-6 of workshop C of a certain standard crude farm

[0060] Pool Number strain stage Death tail number Put the decimal Survival rate Shrimp fry quality 1 High resistance PL4 2 167 98.8％ better 2 High resistance PL4 5 156 96.7％ better 3 High resistance PL4 4 166 97.6％ better 4 High resistance PL4 16 168 90.4％ better 5 High resistance PL4 7 157 95.5％ better

[0061] It can be seen from the test results in Table 3 that the quality of shrimp fry tested in different pools of the same workshop, strain and same developmental stage PL4 is different. It is difficult to distinguish the quality of shrimp fry only by naked eye observation or microscopic examination, and the anti-desalination test in the prior art is difficult to distinguish the true stress resistance of shrimp fry. The povidone-iodine anti-stress test method for shrimp fry of the present invention provides an effective reference for farmers to judge the quality of shrimp fry.

[0062] The present application provides a method for testing povidone-iodine stress of white shrimp fry, which reflects the stress resistance of shrimp fry by measuring the survival rate of povidone-iodine stress of white shrimp fry, and also reflects the disease resistance of shrimp fry, providing data basis for the selection and cultivation of shrimp fry, solving the problem of lack of testing of the chemical and environmental stress resistance of shrimp fry at various stages in the prior art, providing a basis for hatcheries to judge the disease resistance and stress resistance of shrimp fry, and the screened shrimp fry can reduce the stress response caused by environmental changes during transportation, which is an effective means to judge the stress resistance quality of white shrimp fry at various developmental stages.

[0063] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for testing povidone-iodine stress of white shrimp fry, characterized in that: The following steps are involved: S1. Prepare a stress test adaptor, which comprises the following components by weight: 2-7 parts of glutathione, 30-80 parts of astragalus polysaccharide, 20-30 parts of vitamin C phosphate, 30-80 parts of water and 0.5-1.5 parts of a surfactant, wherein the surfactant is any one of sodium lauroyl glutamate, sodium dodecylbenzene sulfonate and sorbitan monostearate; S2. Place a certain proportion of shrimp fry in container A containing the original pond water. The development stage is PL 4-9 The shrimp seed placement ratio is 1:120-140 liters / tail, and the development stage is PL 10 or PL 10 The above shrimp fry are placed at a ratio of 1:90-115 liters / tail, and the stress test adaptogen prepared in step S1 is added into container A, and the container is kept inflated for 12-14 hours; S3, take out 1 / 5-3 / 5 of the healthy shrimp seedlings in the container A after inflation in step S2, and put them into the container B containing the original pond water containing povidone iodine, the effective content of povidone iodine is ≥99%, the effective iodine content is 10%, and the povidone iodine concentration in the original pond water is 400-600ppm, keep inflation and avoid light, and the inflation time is 30-40min; S4, take out the shrimp fry in the aerated container B in step S3, put it into the container C filled with only the original pond water and aerate it for 30 minutes. After the aeration is completed, the shrimp fry are divided into two groups according to the development stage PL N , calculate the stress survival rate of shrimp fry and judge the quality of shrimp fry, where N represents the value of the shrimp fry development stage; S5. The formula for calculating stress survival rate is: stress survival rate % = 100 × (total number of shrimp seedlings - number of dead seedlings) / total number of shrimp seedlings; S6. Evaluation criteria: Setting the PL of shrimp fry development stage 4-9 The survival rate of 90% is the standard survival rate of shrimp fry, and the survival rate of shrimp fry development stage PL is set 10 or PL 10 The above survival rate of 93% is the standard survival rate of shrimp fry.

2. The method for testing the povidone-iodine stress of Penaeus vannamei fry according to claim 1, characterized in that: The dead shrimps include shrimps that sink to the bottom and die, shrimps that lie on their sides, shrimps that can swim or swim intermittently and twitch, and shrimps that swim in circles.

3. The method for testing the povidone-iodine stress of Penaeus vannamei fry according to claim 1, characterized in that: If the calculated shrimp fry development stage PL in step S5 4-9 If the survival rate is greater than 90%, the PL 4-9 The shrimp seedlings in the development stage have better stress resistance quality; if the calculated shrimp seedling development stage PL 10 If the survival rate is greater than 93%, the PL 10 or PL 10 The shrimp fry in the above stages have better stress resistance.

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