Crayfish improved variety breeding device and application thereof

Abstract

The invention discloses a procambarus clarkii improved variety breeding device and application thereof. The device comprises a group selection unit and a family selection unit, the overall structure of the group selection unit is a cuboid, the group selection unit comprises a group selection water tank, a group selection shrimp box and a shrimp nest, the group selection shrimp box is detachably embedded into the group selection water tank, and the shrimp nest is detachably embedded into a side interlayer of the group selection shrimp box and the group selection water tank; the overall structure of the family selection unit is a cylinder, the family selection unit comprises a family selection water tank, a family selection shrimp box and a shrimp nest, the family selection shrimp box is detachably embedded into the family selection water tank, and the shrimp nest is detachably embedded into a lateral interlayer of the family selection water tank and the family selection shrimp box. The breeding method has the advantages that parent individuals with strong bodies and high stress resistance are bred by utilizing self behavior characteristics and external nest position advantages of the crayfish, and then the nest position advantages are removed to breed individuals with high fecundity; and a crayfish parent with stable hereditary characters is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural applications, and relates to a cultivation and breeding method for crayfish, specifically a crayfish improved variety breeding device and its application. Background Art

[0002] Crayfish are omnivorous animals with a wide range of food sources. They mainly feed on aquatic plants and also consume some animal foods. Crayfish generally feed on various tender aquatic plants, benthic animals, mollusks, large phytoplankton, the corpses of fish and shrimp, and the corpses of their own kind. They can live and breed in environments such as ponds, paddy fields, rivers, lakes, ditches, and wetlands. At present, the vast majority of crayfish sold on the market come from artificial breeding. Therefore, the selection of breeding varieties has become increasingly important for their quality.

[0003] In the prior art, the variety selection of crayfish often adopts the method of mass selection, that is, selecting excellent parents with good traits to form a population, and gradually selecting the best and breeding from generation to generation until the average traits are significantly improved. Since crayfish are sedentary organisms, under natural conditions, individuals with excellent traits first occupy suitable positions and preferentially mate and reproduce, showing strong physical strength (strong stress resistance), which is the target excellent trait for selection. However, in the process of breeding practice, individuals with large body sizes are often selected by observation methods (the stress resistance may not be strong), that is, the observation methods and standards alone cannot fully and truly reflect their natural excellent attributes. Therefore, the accuracy of improved variety selection is affected.

[0004] Chinese Patent Application CN1792348A discloses a breeding method for freshwater crayfish. The hybrid parents are female Procambarus clarkii with a body weight of 93 g - 150 g and a strong build, and male Australian freshwater crayfish with a body weight of 180 g - 250 g and a strong build. Multiple generations of selective breeding and repeated hybridization are carried out. Select strong Procambarus clarkii as the female parent and strong Australian freshwater crayfish as the male parent for mating to produce the first-generation selected shrimp. Then, the female shrimp in the first-generation selected shrimp are mated with the male shrimp of Australian freshwater crayfish to produce the second-generation selected shrimp, and the second-generation selected shrimp are used as shrimp seeds. The design idea of this prior art is: selecting individuals with large body weights through apparent traits, and using the F1 generation to backcross with the male parent to obtain the BC1F generation, so that the selected shrimp seeds have more genetic advantages of Australian freshwater crayfish. However, from the perspective of molecular genetics, its defects are as follows: First, simply selecting parent individuals from the perspective of apparent traits (such as body weight), their stress resistance may not be strong. Therefore, the selected offspring cannot accurately ensure strong stress resistance and reproductive ability. Second, the Australian freshwater crayfish itself has a relatively large body weight. When the purpose of seed selection cannot be achieved only based on apparent traits, the BC1F generation obtained after backcrossing with the male parent is even less likely to meet the requirements of breeding. Third, even if the selected Australian freshwater crayfish individuals meet the breeding purpose, the trait stability of the backcross offspring is weaker than that of the hybrid offspring. Summary of the Invention

[0005] Technical problems to be solved: In order to overcome the deficiencies of the prior art, reduce the errors in selecting breeding individuals based solely on apparent traits, and utilize the living habits and behavior patterns of crayfish to improve the accuracy of breeding. In view of this, the present invention provides a device for selecting superior crayfish breeds and its application.

[0006] Technical solution: A device for selecting superior crayfish breeds, the device includes a population selection unit and a family selection unit; the overall structure of the population selection unit is a cuboid, including a population selection water tank, a population selection shrimp box and a shrimp nest, wherein the population selection shrimp box is detachably embedded in the population selection water tank, and the shrimp nest is detachably embedded in the side sandwich layer between the population selection shrimp box and the population selection water tank; the overall structure of the family selection unit is a cylinder, including a family selection water tank, a family selection shrimp box and a shrimp nest, wherein the family selection shrimp box is detachably embedded in the family selection water tank, and the shrimp nest is detachably embedded in the side sandwich layer between the family selection water tank and the family selection shrimp box.

[0007] Preferably, the shrimp nest includes a shrimp passage, the top of the shrimp passage is provided with a nest opening, the bottom is closed, and the shrimp passage gradually narrows and bends from the bottom to the top to form a flat part and an inclined part.

[0008] Preferably, the upper surface of the flat part is transparent, and both sides are of a net structure; the upper surface of the inclined part is transparent, and both sides and the bottom are of a net structure. This structural design can, on the one hand, ensure that crayfish can enter and exit the shrimp passage conveniently, and on the other hand, facilitate the operator to observe the mating situation in the shrimp passage and take out male and female shrimps in time.

[0009] Preferably, the cross-sections of both the population selection shrimp box and the family selection shrimp box are trapezoids, and circular holes are evenly opened on the side surfaces; micropores are evenly opened at the bottom of the shrimp box for oxygen to enter the water tank. Further, the circular holes are opened in the middle of the side surface of the shrimp box.

[0010] Preferably, the outer inclination slope of the side surface of the shrimp box is 15 - 30°, and the upper end is higher than the water tank to prevent crayfish from entering the water tank.

[0011] Preferably, the nest opening of the shrimp nest is engaged with the circular hole, and the bottom is tightly attached to the inner wall of the water tank to ensure that after the shrimp nest is installed, its flat part is at the lowest position of the shrimp nest.

[0012] Preferably, the water depth in the shrimp box is 20 - 25 cm, the inner diameter of the nest opening is 3 - 5 cm, and the nest opening is 0 - 10 cm below the water surface.

[0013] Preferably, the shrimp box and the water tank are detachably connected by toes.

[0014] Application of any of the above-mentioned devices for selecting superior crayfish breeds in improving the accuracy of selecting superior crayfish breeds.

[0015] Preferably, the application includes the following steps:

[0016] S1. Mass selection

[0017] Add water to the mass selection shrimp box until the water surface is 0 - 10 cm higher than the upper edge of the round hole, so that the whole shrimp nest is underwater. Place the parent shrimps in the mass selection shrimp box. The number of parent shrimps is 2 - 3 times the number of shrimp nests, and the ratio of female shrimps to male shrimps is 1:2 - 3. Let it stand until the strong parent shrimp individuals enter the shrimp nest. When there is a pair of male and female in the shrimp nest, remove the shrimp nest, and then put the shrimp nest into the family selection unit.

[0018] S2. Family selection

[0019] Add water to the family selection shrimp box until the water surface is 0 - 10 cm higher than the upper edge of the round hole. After the shrimp nest is placed in the family selection unit, cover the family selection shrimp box with a round lid. After mating is completed, remove the male shrimps, leave the female shrimps with eggs in the shrimp nest, and move out the female shrimps after the larvae break away from the mother body. Keep the larvae in the family selection shrimp box for continued cultivation, and adjust the water level in the box, control the water temperature and feeding according to the living habits of the larvae.

[0020] During the breeding season, place the female and male shrimps of a single family in different mass selection shrimp boxes respectively, and repeat steps S2 and S3 for 3 - 5 generations, then the fine variety breeding of crayfish can be achieved, and the parent individuals with strong physique and strong reproductive ability can be accurately selected.

[0021] The principle of the crayfish fine variety breeding device and its application of the present invention is as follows: First, the overall structure of the mass selection unit is a cuboid, while the overall structure of the family selection unit is a cylinder. The reason for this design is that in the process of mass selection, the cuboid box shape has a nest position advantage. The strong shrimps selected from ponds or lakes need to rely on their own competitiveness to compete for nest positions, otherwise they cannot get the breeding opportunity. Therefore, in this step, the parent individuals that are large in size but lack competitiveness due to artificial selection can be excluded. While the cylinder box shape has no nest position advantage, and the pair of male and female shrimps in its shrimp nest give priority to reproductive ability. Therefore, under the condition of ensuring the same breeding conditions, those that develop and reproduce first will be selected first. Second, after the family selection is completed, place the male and female shrimps of the same family in different mass selection units respectively, continue to repeat mass selection and family selection, and both adopt the form of hybridization, which can avoid the problems of unstable traits and trait regression caused by inbreeding within the same family.

[0022] Beneficial effects: (1) The crayfish fine variety breeding device and application method of the present invention utilize the self - behavior characteristics of crayfish (such as burrowing habits, male shrimp fighting, etc.) and external nest position advantages to first select the parent individuals with strong physique and strong stress resistance, and then remove the nest position advantage to select the individuals with strong reproductive ability; (2) Through hybridization between different families and the selection of the dominant population for 3 - 5 generations, the crayfish parents with stable genetic traits are obtained. Description of the Drawings

[0023] Figure 1 is a schematic diagram of the overall structure of the population selection unit;

[0024] Figure 2 is a schematic diagram of the structure of the population selection water tank;

[0025] Figure 3 is a schematic diagram of the structure of the population selection shrimp box;

[0026] Figure 4 is a schematic diagram of the structure of the shrimp nest;

[0027] Figure 5 is a schematic diagram of the structure of the family selection water tank;

[0028] Figure 6 is a schematic diagram of the structure of the family selection shrimp box;

[0029] Among them, 1 is the population selection water tank, 2 is the population selection shrimp box, 3 is the shrimp nest, 4 is the round hole, 5 is the toe, 6 is the nest opening, 7 is the shrimp path, 8 is the inclined part, 9 is the flat part, 10 is the family selection water tank, and 11 is the family selection shrimp box. Detailed Implementation Modes

[0030] The following embodiments further illustrate the content of the present invention, but should not be construed as a limitation to the present invention. Without departing from the spirit and essence of the present invention, modifications and substitutions made to the methods, steps or conditions of the present invention all fall within the scope of the present invention. If not specifically specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0031] Embodiment 1

[0032] A crayfish improved variety breeding device, the device includes a population selection unit and a family selection unit; the overall structure of the population selection unit is a cuboid, including a population selection water tank 1, a population selection shrimp box 2 and a shrimp nest 3, wherein the population selection shrimp box 2 is detachably embedded in the population selection water tank 1, and the shrimp nest 3 is detachably embedded in the side sandwich layer between the population selection shrimp box 2 and the population selection water tank 1; the overall structure of the family selection unit is a cylinder, including a family selection water tank 10, a family selection shrimp box 11 and a shrimp nest 3, wherein the family selection shrimp box 11 is detachably embedded in the family selection water tank 10, and the shrimp nest 3 is detachably embedded in the side sandwich layer between the family selection water tank 10 and the family selection shrimp box 11.

[0033] The shrimp nest 3 includes a shrimp path 7, the top of the shrimp path 7 is provided with a nest opening 6 and the bottom is closed, and the shrimp path 7 gradually narrows and bends from the bottom to the top to form a flat part 9 and an inclined part 8.

[0034] The upper surface of the flat part 9 is transparent, and both sides are of a mesh structure; the upper surface of the inclined part 8 is transparent, and both sides and the bottom are of a mesh structure.

[0035] The cross-sections of both the population selection shrimp box 2 and the family selection shrimp box 11 are trapezoidal, with circular holes 4 evenly opened on the sides; micropores are evenly opened at the bottom of the shrimp box to allow oxygen to enter the water tank.

[0036] The outer inclination slope of the side of the shrimp box is 20°, and the upper end is higher than the water tank.

[0037] The nest opening 6 of the shrimp nest 3 is engaged with the circular hole 4, and the bottom is closely attached to the inner wall of the water tank.

[0038] The water depth in the shrimp box is 20 cm, the inner diameter of the nest opening 6 is 3 cm, and the nest opening 6 is 10 cm below the water surface.

[0039] The shrimp box is detachably connected to the water tank through the toe.

[0040] The structural design and parameter range of this embodiment are most suitable for practical applications and are the best embodiment.

[0041] Embodiment 2

[0042] The difference from Embodiment 1 is that the outer inclination slope of the side of the shrimp box is 15° or 30°, the water depth in the shrimp box is 25 cm, the inner diameter of the nest opening 6 is 5 cm, and the nest opening 6 is 0 cm below the water surface.

[0043] Under the parameter range conditions of this embodiment, the crayfish can also enter and exit the shrimp nest and complete the breeding process. However, compared with Embodiment 1, the difficulty of entry and exit is greater, so the efficiency is slightly lower than that of Embodiment 1. And compared with Embodiment 1, the oxygen content in the shrimp nest 3 is higher, so the selection of the stress resistance of the crayfish parents is weaker.

[0044] Embodiment 3

[0045] The device described in Embodiment 1 is actually used for the breeding of high-quality crayfish. The specific scheme is as follows:

[0046] S1. Population selection

[0047] Add water to the population selection shrimp box 2 until the water surface is 0 - 10 cm above the upper edge of the circular hole 4, so that the whole shrimp nest 3 is underwater. Place the parent shrimps in the population selection shrimp box 2. The number of parent shrimps is 2 - 3 times the number of shrimp nests 3, and the ratio of female shrimps to male shrimps is 1:2 - 3; let it stand until the strong parent shrimp individuals enter the shrimp nest 3. When there is a pair of male and female in the shrimp nest 3, remove the shrimp nest 3, and then put the shrimp nest 3 into the family selection unit;

[0048] S2. Family selection

[0049] Add water to the family selection shrimp box 11 so that the water surface is 0-10 cm higher than the upper edge of the round hole 4. After the shrimp nest 3 is placed in the family selection unit, cover the family selection shrimp box 11 with a round cover. After mating is completed, take out the male shrimp, leave the female shrimp with eggs in the shrimp nest 3, and remove the female shrimp after the larvae break away from the mother body; leave the larvae in the family selection shrimp box 11 for continued cultivation, and adjust the water level in the box, control the water temperature and feed according to the living habits of the larvae;

[0050] During the breeding season, place the female and male shrimps of a single family in different population selection shrimp boxes 2 respectively, and repeat steps S2 and S3 for 3-5 generations to achieve the selective breeding of crayfish and accurately select parent individuals with strong physique and strong reproductive ability.

Claims

1. Crayfish improved variety breeding device, characterized in that The device includes a population selection unit and a pedigree selection unit; the overall structure of the population selection unit is a cuboid, including a population selection water tank (1), a population selection shrimp tank (2) and a shrimp nest (3). The population selection shrimp tank (2) is detachably embedded in the population selection water tank (1), and the shrimp nest (3) is detachably embedded in the side sandwich layer between the population selection shrimp tank (2) and the population selection water tank (1); the overall structure of the pedigree selection unit is a cylinder, including a pedigree selection water tank (10), a pedigree selection shrimp tank (11) and a shrimp nest (3). The pedigree selection shrimp tank (11) is detachably embedded in the pedigree selection water tank (10), and the shrimp nest (3) is detachably embedded in the side sandwich layer between the pedigree selection water tank (10) and the pedigree selection shrimp tank (11).

2. The crayfish improved variety breeding device according to claim 1, characterized in that, The shrimp nest (3) includes a shrimp passage (7). The top of the shrimp passage (7) is provided with a nest opening (6) and the bottom is closed. The shrimp passage (7) gradually narrows and bends from the bottom to the top to form a flat part (9) and an inclined part (8).

3. The crayfish improved variety breeding device according to claim 2, characterized in that, The upper surface of the flat part (9) is transparent and both sides are of a mesh structure; the upper surface of the inclined part (8) is transparent and both sides and the bottom are of a mesh structure.

4. The crayfish improved variety breeding device according to claim 2, characterized in that The cross-sections of the population selection shrimp tank (2) and the pedigree selection shrimp tank (11) are both trapezoidal, and circular holes (4) are evenly opened on the side surfaces; micropores are evenly opened at the bottom of the shrimp tank for oxygen to enter the water tank.

5. The crayfish improved variety breeding device according to claim 4, characterized in that, The outer slope of the side surface of the shrimp tank is 15 - 30°, and the upper end is higher than the water tank.

6. The crayfish improved variety breeding device according to claim 2, characterized in that, The nest opening (6) of the shrimp nest (3) is engaged with the circular hole (4), and the bottom is closely attached to the inner wall of the water tank.

7. The crayfish improved variety breeding device according to claim 2, characterized in that, The water depth in the shrimp tank is 20 - 25 cm, the inner diameter of the nest opening (6) is 3 - 5 cm, and the nest opening (6) is 0 - 10 cm below the water surface.

8. The crayfish improved variety breeding device according to claim 1, characterized in that The shrimp tank and the water tank are detachably connected by toes.

9. Application of the crayfish improved variety breeding device according to any one of claims 1 - 8 in improving the accuracy of crayfish improved variety selection.

10. The application according to claim 9, wherein The application includes the following steps: S1. Population selection Add water to the population selection shrimp tank (2) until the water surface is 0 - 10 cm above the upper edge of the circular hole (4), so that the whole shrimp nest (3) is underwater. Place the parent shrimps in the population selection shrimp tank (2). The number of parent shrimps is 2 - 3 times the number of shrimp nests (3), and the ratio of female shrimps to male shrimps is 1:2 - 3; let it stand until the strong parent shrimp individuals enter the shrimp nest (3). When there is a pair of male and female in the shrimp nest (3), remove the shrimp nest (3), and then put the shrimp nest (3) into the pedigree selection unit; S2. Pedigree selection Add water to the pedigree selection shrimp tank (11) until the water surface is 0 - 10 cm above the upper edge of the circular hole (4). After the shrimp nest (3) is placed in the pedigree selection unit, cover the pedigree selection shrimp tank (11) with a round cover. After mating is completed, remove the male shrimps, leave the broodstock female shrimps in the shrimp nest (3), and remove the female shrimps after the larvae break away from the mother body; leave the larvae in the pedigree selection shrimp tank (11) for continuous cultivation, and adjust the water level in the tank, control the water temperature and feed according to the living habits of the larvae; During the breeding season, place the female and male shrimps of a single pedigree in different population selection shrimp tanks (2) respectively, and repeat steps S2 and S3 for 3 - 5 generations, then the improved variety breeding of crayfish can be realized, and the parent individuals with strong physique and strong reproductive ability can be accurately selected.

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