A method for raising seedlings of yellow eel in family system

Abstract

The present invention provides a method for breeding rice field eels in a family, redefines the source and standard of parents, adopts ecologically simulated semi-artificial propagation technology, improves domestication methods, improves devices, perfects order screening schemes, accurately selects and breeds from generation to generation, and quickly establishes a family that is easy to domesticate and grows fast on the basis of reducing the difficulty of operation; in the present invention, anti-stress treatment is performed on rice field eels, which improves the quality of parent eels, thereby helping to improve the efficiency of induced labor, facilitating large-scale family construction, and expanding the selection range; in the present invention, a new type of enhanced cultivation device and egg-laying and hatching device are utilized, a drug formula for promoting the gonadal development of rice field eels is formulated, and an order screening technology is matched.

Description

Technical Field

[0001] The invention relates to the technical field of rubber tree planting, and in particular to a method for raising seedlings of a rice field eel family. Background Art

[0002] Yellow field eel (Monopterus albus), also known as eel, is a freshwater benthic omnivorous fish that mainly feeds on animal bait. Because of its tender meat, delicious taste, rich nutrition, and certain medicinal value, it has a strong consumer demand and the industry is developing rapidly. Seedling quality is the key to the healthy and sustainable development of the industry. Breeding yellow field eel varieties that are easy to domesticate and grow fast has become the only way to improve the quality of industrial development. Family selection breeding technology refers to the selection based on family units, which aims to improve and stabilize the main economic traits by increasing the frequency of target genes in the breeding population.

[0003] At present, there are reports on the selection of eel families, and CN114982679A provides a method for establishing eel families and selecting excellent families, which provides a technology for obtaining high-yield eel families through family selection. However, this method has high technical requirements in practical application, requires rich operating experience, and does not involve easy domestication traits.

[0004] Therefore, it is an urgent problem to provide a method for raising seedlings in a family that is easy to operate, can be quickly established, is easy to domesticate, and grows fast. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for raising seedlings of a family of yellow eel, which redefines the source and standard of parents, adopts ecological semi-artificial breeding technology, improves the domestication method, improves the device, improves the order screening scheme, accurately selects and breeds from generation to generation, and quickly establishes a family that is easy to domesticate and grows fast on the basis of reducing the difficulty of operation. The method specifically includes the following steps:

[0006] Step 1: Parent selection

[0007] Select one-winter-aged yellow eels that are disease-free, healthy, and free of rhabdovirus, with bright yellow body color and large spots, and weigh 45-150g, of which the female eels are 20-24cm long; treat the yellow eels with complex vitamins and magnolia water solution to reduce the stress of the yellow eels;

[0008] Step 2: Strengthen cultivation

[0009] Male and female eels are cultured separately and placed in intensive culture ponds and marked; the stocking density is 3-5 eels / cubic water body, and mixed bait is added to each pond twice a day, morning and evening, and the amount added is 3-5% of the weight of the eels in each pond;

[0010] Step 3: Promote development

[0011] Promote development: After 15-20 days of intensive cultivation, keep the water temperature of the female eel pool at 20-22℃; the water temperature of the male eel pool at 22-24℃ and add mixed Chinese medicine; start to check the sexual maturity of female and male eels after 25 days, and induce spawning when the eels are fully developed;

[0012] Step 4: Inducing labor

[0013] Select mature male and female eels for induced spawning injection, and place them in egg-laying and hatching tanks, with one female eel and one male eel in each tank;

[0014] Step 5: Incubation and seedling raising

[0015] Eliminate the group with less than 150 eggs, hatch naturally, and feed water silk earthworms after the yolk disappears and the eels swim, three times a day, 50g each time; start domestication after seven days of feeding, the eel fry in each tank is a family, eliminate the family with less than 150 tails; divide each family that has not been eliminated equally into three tanks;

[0016] Step 6: Domestication selection

[0017] On the eighth day, the sequential screening began, and the acclimation time, acclimation rate, and weight of seedlings of each family at 15 days, 30 days, and 130 days were counted until the families that were easy to acclimate and grow fast were selected.

[0018] Preferably, the total amount of the vitamin complex in step 1 is 15g, the total amount of magnolia is 5g, and the vitamin complex includes vitamin A, vitamin B 2 , vitamin D, vitamin E, the mass ratio is 1:1:1:1. When using, first mix magnolia with 1L water, then boil it to 500ml, filter it, wait for the filtrate to cool, then dissolve the multivitamin into the boiled magnolia water, mix evenly and dilute it 10 times to soak the eel.

[0019] Preferably, the mixed bait in step 2 needs to be soaked in medicine for 72 hours before being released; the mixed bait is loach with a body length of 5-10 cm and fresh water worm, with a mass ratio of 1:1.

[0020] Preferably, the drugs are cloves and galangal, with a mass ratio of 1:1, and the total amount of the drugs is 2% of the mass of the mixed bait. After the drugs are mixed, 1.5L of water is added, and then decocted to 500ml, filtered, and the filtrate is cooled and diluted 10 times to soak the bait.

[0021] Preferably, the amount of the mixed Chinese medicine added in step three is 1% of the weight of the male eels in the pond, and the mixed Chinese medicine is astragalus and wolfberry, and the mass ratio is 1:2.

[0022] Preferably, in step 4, the injection amount of female eels is: LHRH-A2 is 5 μg / kg, HCG is 800 units / kg, and the injection amount of male eels is 1 / 4 of the injection amount of female eels.

[0023] Preferably, the order screening operation in step six is:

[0024] In the first stage, each family began to carry out the acclimation experiment on the 8th day, and directly fed the artificial compound feed, and selected the families with high feeding ratio (7-day acclimation tail number ≥ 1) for the next breeding experiment;

[0025] In the second stage, water silkworms were fed from the 8th day to the 10th day, and water silkworms and artificial compound feed were mixed and fed from the 11th day. During this period, families with a high proportion of artificial feed intake and a short time (i.e., 80% of the time spent by the eels eating artificial compound feed) were selected;

[0026] The artificial compound feed includes, by mass fraction, 25% fish meal, 21% soybean meal, 34% corn meal, 9% bran, 9.6% peanut meal, 0.3% inorganic salt, 1% sucrose, and 0.1% rice bran;

[0027] The mixing mass ratio of the water silk earthworm and the artificial compound feed is: 4:1 on the 11th to 12th day, 1:1 on the 13th day, 1:4 on the 14th day, and all artificial compound feed from the 15th day onwards;

[0028] The third stage is to breed the families selected in the first and second stages together with the remaining families, measure the weight of seedlings at different ages, and identify the families that are easy to domesticate and grow fast.

[0029] Preferably, the enhanced breeding pool in step 2 is provided with a water inlet pipe and a drainage pipe, and an eel nest, a heating rod and a temperature sensor are provided inside the enhanced breeding pool; a temperature display panel is provided on the outer surface of the enhanced breeding pool, and the temperature display panel and the temperature sensor are electrically connected.

[0030] The enhanced cultivation pool is made of black fiberglass or food-grade PVC.

[0031] Preferably, the hatching tank in step 4 is provided with two water inlet pipes and two drainage pipes, two eel nests and an artificial pile are provided inside the hatching tank, and the hatching tank is also provided with a camera, which is installed on the side wall of the hatching tank through a mounting frame.

[0032] The hatching tank is made of food-grade PVC material.

[0033] The present invention has the following advantages:

[0034] (1) In the present invention, yellow eels from rice-shrimp fields are selected as parents, and are screened based on body weight and virus detection results. At the same time, anti-stress treatment is performed to improve the quality of the parent eels, thereby helping to improve the efficiency of induced spawning, facilitating large-scale family construction, and expanding the selection range.

[0035] (2) Compared with other methods, the present invention utilizes a new type of enhanced cultivation device and egg-laying and hatching device, formulates a drug formula to promote the gonadal development of yellow eels, and uses a matching order screening technology. Its advantages are: first, it can reduce the degree of asynchrony in the gonadal development of male and female eels; second, it uses a comprehensive use of devices, drugs, etc. to improve the efficiency of family construction; third, it reduces the stress response and injury rate of eel seedlings, and can conduct selective breeding based on domestication efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 To strengthen the cross-section of the culture pond;

[0038] Figure 2 This is a cross-sectional view of the hatching tank. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] The method for raising rice field eels in a family system in this embodiment comprises the following steps:

[0042] Step 1: Parent selection

[0043] In early April 2023, 150 winter-aged eels weighing 45-150g were captured from local rice-shrimp fields using eel cages. They were healthy, had no rhabdovirus, were bright yellow with large spots, and were healthy. Female eels were 20-24cm long and weighed 45-150g. The captured eels were treated with multivitamins and magnolia water to reduce their stress. They were used as parents to build breeding families.

[0044] The total dosage of the multivitamin is 15g, the total dosage of magnolia is 5g, and the multivitamin includes vitamin A, vitamin B 2, vitamin D, vitamin E, the mass ratio is 1:1:1:1. When using, first mix magnolia with 1L water, then boil it to 500ml, filter it, wait for the filtrate to cool, then dissolve the multivitamin into the boiled magnolia water, mix evenly and dilute it 10 times for soaking.

[0045] Step 2: Strengthen training

[0046] The male and female eels are cultivated separately and placed in 30 enhanced cultivation ponds 1 respectively, and marked as 1-30; the stocking density is 5 eels / cubic water body, and mixed bait is added twice a day in the morning and evening in each pond according to 3% of the weight of the eel, and the mixed bait includes loach with a body length of 5-10 cm and fresh water silk earthworms, and the mass ratio is 1:1; the mixed bait needs to be soaked in drugs for 72 hours before being put in; the drugs are cloves and galangal, and the mass ratio is 1:1, and the total amount of drugs is 2% of the mass of the mixed bait; 2 / 3 of the water surface in the enhanced cultivation pond 1 is covered with large wormwood; the water temperature is kept at 18-24℃ by heating rods;

[0047] The cloves and galangal are mixed and then 1.5 L of water is added, and then decocted to 500 ml, filtered, and the filtrate is cooled and diluted 10 times to soak the bait;

[0048] The enhanced breeding pond 1 is made of food-grade PVC material, with a length of 2m, a width of 1m and a height of 0.5m; the enhanced breeding pond 1 is provided with an inlet pipe 105 and a drain pipe 103; the diameter of the drain pipe 103 is 25mm, the outlet of the drain pipe 103 is 15cm higher than the inlet, and the outlet and inlet of the drain pipe 103 are respectively provided with a filter 104 to prevent the escape of the eel and the mixed bait; an eel nest 101 is provided inside the enhanced breeding pond 1, and a heating rod 102 is provided at the bottom of the enhanced breeding pond 1, and the power of the heating rod 102 is 200W; a temperature sensor 108 is installed on the inner wall of the enhanced breeding pond 1, and a temperature display panel 106 is installed on the side wall of the enhanced breeding pond 1 through a support column 107; the temperature sensor 108 and the temperature display panel 106 are electrically connected.

[0049] Step 3: Promote development

[0050] Starting from April 20, the water temperature of the female eel pond was maintained at 20-22℃, with a fluctuation of no more than 2℃; the water temperature of the male eel pond was maintained at 22-24℃, with a fluctuation of no more than 2℃, and mixed Chinese medicine was added at 1% of the weight of the male yellow eels in the pond; the mixed Chinese medicine was astragalus and wolfberry, with a mass ratio of 1:2; from May 19, the sexual maturity of female and male eels was randomly checked, and the visual judgment method was used for female eels, that is, after the female eels were anesthetized, the back of the head was gently pinched with the hand, and the abdomen was observed against the light. 82 eels had yellow, plump, granular eggs, and the abdomen was gently pressed with the hand. 78 sexually mature eels had eggs discharged; 5 male eels were randomly selected, and after dissection, it was determined that 80% of the male eels were fully developed and could be subjected to ecological induced spawning; 30 pairs of them were selected for family line construction.

[0051] Step 4: Eco-friendly induced labor

[0052] 60 male and female parent eels were injected with induced labor, the female eels were injected with 5 micrograms / kg of LHRH-A2 and 800 units / kg of HCG, and the male eels were injected with 1 / 4 of the amount of female eels per kg. After the injection, they were placed in 2 spawning and hatching tanks, with one female eel and one male eel in each tank; the water temperature was 20.5℃, the water was micro-flowing, and the flow rate was 0.1-0.5m / s.

[0053] The hatching tank 2 is 1m long, 0.8m wide, and 0.6m high, and is made of food-grade PVC. The hatching tank 2 is provided with an inlet pipe 202 and a drain pipe 201, and a filter screen 203 is provided at the inlet and outlet of the drain pipe 201 respectively; two eel nests 204 are arranged inside the hatching tank 2, and the eel nests 204 are 0.5m long, 0.4m wide, and 0.3m high, and are made of PVC; an artificial pile 205 surrounded by a polyethylene mesh with a pore size of 2mm is also arranged inside the hatching tank 2, and the artificial pile 205 is 0.8m long, 0.5m wide, and 0.45m high, and the artificial pile 205 is covered with 3 large mulberries tied into a bundle near the water surface; a camera 207 is installed on the side wall of the hatching tank 2 through a mounting frame 206; the hatching tank 2 is placed in a quiet environment.

[0054] Step 5: Incubation and seedling raising

[0055] There were 7 groups with egg laying rate less than 150 and no egg laying. After natural hatching, 23 groups had more than 150 fry. After all fry had lost their yolk and swam, they were fed with water silk earthworms, with a feeding amount of 50g, three times a day in the morning, noon and evening. Domestication began after seven days of feeding. The eel fry in each trough was a family, numbered Gn, n=1, 2, 3...23; each family was divided into three troughs, with 50 fry in each trough; the three troughs of the first family were numbered G1-1, G1-2, and G1-3, and so on. The nth family was numbered Gn-1, Gn-2, and Gn-3, and Gn-1 formed a group, Gn-2 formed a group, and Gn-3 formed a group for domestication selection experiments.

[0056] Step 6: Domestication selection

[0057] On the eighth day, the sequential screening began, and the domestication time, domestication rate, and weight of seedlings at 15, 30, and 130 days of age were counted until the families that were easy to domesticate and grew fast were selected.

[0058] First-order experiment: On the eighth day, the family numbered Gn-1 began to carry out the acclimation experiment. First, they fed the artificial compound feed directly, and replaced the fresh artificial compound feed three times a day. The feeding situation was counted, and the family with a high feeding ratio (7-day acclimation tail number ≥ 1) was selected for the next breeding experiment;

[0059] The second stage experiment: from the eighth day to the tenth day, the family numbered Gn-2 was fed with water silkworms, and from the eleventh day, it was fed with a mixture of water silkworms and artificial compound feed. During this period, the family with a high proportion of artificial feed intake and a short time (i.e., 80% of the time spent by the eels eating artificial compound feed) was selected;

[0060] The artificial compound feed includes, by mass fraction, 25% fish meal, 21% soybean meal, 34% corn meal, 9% bran, 9.6% peanut meal, 0.3% inorganic salt, 1% sucrose, and 0.1% rice bran;

[0061] The mixing mass ratio of the water silk earthworm and the artificial compound feed is: 4:1 on the 11th to 12th day, 1:1 on the 13th day, 1:4 on the 14th day, and all artificial compound feed from the 15th day onwards;

[0062] The third-order experiment: The families selected in the first and second stages were cultured together with the remaining family numbered Gn-3, and the weight of seedlings at different ages was measured to determine the family that was easy to domesticate and grow fast. The results are shown in Table 1.

[0063] Table 1 Domestication and growth status of different families

[0064]

[0065] As can be seen from Table 1, the G10 family is the easiest to domesticate and has the fastest growth rate, and can be used as a candidate family for breeding; the G1 and G13 families can be used as reserve families; in addition, 93 easily domesticated eel seedlings were obtained, which can be used as the first choice for reserve parents and used for breeding the second generation, and then the method used in the present invention can be repeated for successive breeding.

[0066] Comparative Example 1

[0067] The method for raising seedlings of the yellow eel family in the comparative example was carried out according to the domestication method reported in CN 114982679 A.

[0068] Table 2 Comparison of domestication and growth of different families

[0069]

[0070]

[0071] Compared with the comparative example, Example 1 has more advantages in seven-day acclimation number, 15-day-old, 30-day-old, and 130-day-old growth rates.

[0072] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for raising rice field eels in a family system, characterized in that: The following steps are involved: Step 1: Parent selection Select one-winter-aged yellow eels that are disease-free, injury-free, healthy, and free of rhabdovirus, with bright yellow body color and large spots, weighing 45-150g, of which the female eels are 20-24cm long, and treat the yellow eels with complex vitamins and magnolia water solution; Step 2: Strengthen cultivation Male and female eels are cultured separately and placed in intensive culture ponds and marked; the stocking density is 3-5 eels / cubic water body, and mixed bait is added to each pond twice a day, with the amount added being 3-5% of the weight of the eels in each pond; Step 3: Promote development Promote development: After 15-20 days of intensive cultivation, the water temperature of the female eel pool is 20-22℃; the water temperature of the male eel pool is 22-24℃ and mixed Chinese medicine is added; after 25 days, the sexual maturity of female and male eels begins to be checked, and spawning is induced when the eels are fully developed; Step 4: Inducing labor Select mature male and female eels for induced spawning injection, and place them in egg-laying and hatching tanks, with one female eel and one male eel in each tank; Step 5: Incubation and seedling raising Eliminate the group with less than 150 eggs, hatch naturally, and feed water silk earthworms after the yolk disappears and the eels swim. Start taming after seven days of feeding. The eel fry in each tank are a family, and eliminate the family with less than 150 eels. Divide each family that has not been eliminated equally into three tanks. Step 6: Domestication selection On the eighth day, the sequential screening began, and the domestication time, domestication rate, and weight of seedlings at 15, 30, and 130 days of age were counted until the families that were easy to domesticate and grew fast were selected. The order screening operation is: In the first stage, each family began to carry out the acclimation experiment on the 8th day, directly feeding artificial compound feed, and selected the families with 7-day acclimation tail number ≥ 1 for the next breeding experiment; In the second stage, water silkworms were fed from the 8th day to the 10th day, and water silkworms and artificial compound feed were mixed and fed from the 11th day. During this period, families with a high proportion of artificial feed intake and a short time intake were selected; The third stage is to breed the families selected in the first and second stages together with the remaining families, measure the weight of seedlings at different ages, and determine the families that are easy to domesticate and grow fast; The artificial compound feed includes, by mass fraction, 25% fish meal, 21% soybean meal, 34% corn meal, 9% bran, 9.6% peanut meal, 0.3% inorganic salt, 1% sucrose, and 0.1% rice bran; The mixing mass ratio of the water silk earthworm and the artificial compound feed is: 4:1 on the 11th to 12th day, 1:1 on the 13th day, 1:4 on the 14th day, and all artificial compound feed starting from the 15th day.

2. A method for raising rice field eels in a family system according to claim 1, characterized in that: The total amount of the vitamin complex in step one is 15 g, and the total amount of magnolia is 5 g. The vitamin complex includes vitamin A, vitamin B2, vitamin D, and vitamin E, and the mass ratio is 1:1:1:

1.

3. A method for raising rice field eels in a family system according to claim 1, characterized in that: The mixed bait described in step 2 needs to be soaked in medicine for 72 hours before being released; the mixed bait is loach with a body length of 5-10 cm and fresh water worms, with a mass ratio of 1:

1.

4. A method for raising rice field eels in a family system according to claim 3, characterized in that: The drugs are clove and galangal, the mass ratio is 1:1, and the total amount of the drugs is 2% of the mass of the mixed bait.

5. The method for raising rice field eels in a family system according to claim 1, characterized in that: The amount of the mixed Chinese medicine added in step three is 1% of the weight of the male eels in the pond. The mixed Chinese medicine is astragalus and wolfberry, and the mass ratio is 1:

2.

6. A method for raising rice field eels in a family system according to claim 1, characterized in that: In step 4, the injection dose for female eels is: LHRH-A2 is 5 μg / kg, HCG is 800 units / kg, and the injection dose for male eels is 1 / 4 of the injection dose for female eels.

7. A method for raising rice field eels in a family system according to claim 1, characterized in that: In step 5, feed the water silkworm three times a day, 50g each time.

8. The method for raising rice field eels in a family system according to claim 1, characterized in that: The enhanced breeding pool described in step 2 is provided with a water inlet pipe and a drainage pipe, and an eel nest, a heating rod and a temperature sensor are provided inside the enhanced breeding pool; a temperature display panel is provided on the outer surface of the enhanced breeding pool, and the temperature display panel and the temperature sensor are electrically connected.

9. A method for raising rice field eels in a family system according to claim 1, characterized in that: The hatching tank described in step 4 is provided with two water inlet pipes and two drainage pipes, two eel nests and an artificial pile are arranged inside the hatching tank, and a camera is also arranged on the hatching tank, and the camera is installed on the side wall of the hatching tank through a mounting frame.

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