Large-scale breeding device and breeding method for cherax quadricarinatus

Abstract

The invention discloses a large-scale breeding device and method for cherax quadricarinatus. The breeding method comprises the steps of parent shrimp selection and breeding, incubation management and shrimp seed breeding management. Wherein the designed breeding device comprises a hole structure and a shading plate which are bricked in a mating pool, and an inhabiting layer type pore plate for collecting and breeding the young shrimps, so that the mating rate of the parent shrimps, the hatching rate of egg-carrying shrimps and the survival rate of the young shrimps can be effectively increased, the elimination rate of the parent shrimps is greatly reduced, and large-scale production and large-batch emergence of the young cherax quadricarinatus are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of red claw crayfish seedling cultivation, and in particular relates to a large-scale red claw crayfish seedling cultivation device and a seedling cultivation method. Background Art

[0002] Red claw crayfish (Cherax quadricarinatus), native to Australia, is one of the world's most valuable freshwater economic shrimps. Because of its appearance similar to sea lobsters, it is commonly known as Australian freshwater lobster in China. Because red claw crayfish itself has strong resistance to adversity and disease, and good adaptability to the environment, it has advantages in breeding success rate and survival rate. Because of its fast growth rate, large size, and delicious meat, it is favored by many consumers in the domestic market. However, to date, the scale of red claw crayfish breeding is still small, and the degree of industrialization is low, mainly due to the small scale of seedling breeding. The reproduction method of red claw crayfish is through mating between male and female. After mating, the female shrimp ovulates within 24 hours, completes fertilization, and carries eggs for 35-42 days until hatching. Under natural conditions, due to the long spawning period, fertilized eggs are greatly affected by water quality, environment, etc. Even after hatching, the seedlings are easily harmed by natural enemies in nature. Therefore, the issue of seedling quantity is the most basic and important link restricting the development of the red claw crayfish industry. Therefore, a controllable method or measure is urgently needed to achieve large-scale red claw crayfish seedling cultivation.

[0003] The existing methods for breeding red claw crayfish are mainly breeding and hatching in earthen ponds and hatching with egg-carrying shrimps in indoor ponds. (1) Breeding and hatching in earthen ponds: select broodstock that have reached the required size and age, and place them in an outer earthen pond in a certain ratio of male to female to mate naturally. When egg-carrying shrimps begin to appear, use shrimp cages to pick egg-carrying shrimps from the outer ponds to hatching ponds or hatching cages for hatching every day, or let the egg-carrying shrimps hatch naturally in the earthen ponds, and collect shrimp fry from the outer ponds every day using dense-hole shrimp cages; (2) Indoor pond hatching with egg-carrying shrimps: select broodstock that have reached the required size and age, and place them in an indoor pond in a certain ratio of male to female to mate naturally. When egg-carrying shrimps begin to appear, use shrimp cages to pick egg-carrying shrimps from the mating ponds to hatching ponds for hatching every day. After hatching, pick out the egg-carrying shrimps and return them to the mating ponds. The soil pond breeding and hatching method is greatly affected by factors such as weather, water temperature and natural enemies in nature. The mating rate of parent shrimp is low, the egg-carrying shrimp is under great stress, and the egg-carrying shrimp drop many eggs. At the same time, the hatched seedlings are easily eaten by aquatic pests, and the survival rate of seedlings is low; the indoor pool picking egg-carrying shrimp hatching method is relatively controllable, but the egg-carrying shrimp are picked from the mating pond every day. Each operation has a great impact on the egg-carrying shrimp. The egg-carrying shrimp is easy to drop eggs, and the workload is also large. Moreover, it is difficult to pick all the egg-carrying shrimp without draining the water, and some egg-carrying shrimp are still hatched in the mating pond. In general, the existing seedling facilities and methods have problems such as low parent shrimp mating rate and low seedling survival rate, which makes it difficult to achieve large-scale red claw crayfish seedling cultivation, seriously restricting the development of the industry. Summary of the invention

[0004] The purpose of the present invention is to provide a large-scale seedling raising device and seedling raising method for red claw crayfish, which overcomes the defects of existing seedling raising facilities and methods, solves the problems of uncontrollable, low mating rate and low seedling survival rate in seedling raising technology, and realizes the large-scale seedling raising of red claw crayfish.

[0005] To achieve the purpose of the present invention, the present invention provides the following technical solutions: The invention provides a large-scale seedling raising device for red claw crayfish, which comprises a brick cave structure and a sunshade arranged in a mating pool for parent shrimps, and a habitat layer type hole plate arranged in the mating pool for collecting and cultivating shrimp seedlings.

[0006] Furthermore, the brick-built cave structure is a double-layer structure, which is formed by neatly stacking bricks with a size of 23.5 cm×10.5 cm×4.5 cm; the size of the cave is (6-8) cm×(6-8) cm×52.5 cm, and each cave can accommodate 2 shrimps.

[0007] Furthermore, the frame specification of the sunshade is 100cm×60cm×10cm, the frame is connected by PVC plastic pipes, and each of the four corners of the frame has a supporting angle. The frame is covered and fixed with HDPE black film to form a sunshade.

[0008] Furthermore, the production steps of the habitat layer perforated plate are as follows: select a single-layer gusset plate with a specification of 25cm-30cm in width, 0.9cm-1cm in thickness, and a hole specification of about 0.7cm×0.7cm, and cut the gusset plate into small sections evenly and evenly, each section has a specification of (25-30) cm×6cm, and the number of holes in each section is 25; after stacking every 6-8 small sections neatly according to the front side, drill holes at both ends at a distance of 2cm and 4cm from the edge respectively, and use aluminum wire to perforate and bind them to fix.

[0009] The present invention also provides a method for large-scale breeding of red claw crayfish, which utilizes the large-scale breeding device and specifically comprises the following steps: (1) Selection and intensive cultivation of broodstock: Before cultivation, a brick cave structure and sunshade are set up in the broodstock mating pool. After cleaning the mating pool, water is added to a depth of 40 cm and probiotics are sprayed throughout the pool. Broodstock aged 12-16 months are selected and placed in the mating pool for intensive cultivation. The feeding situation of the broodstock is observed daily and the feeding amount is adjusted in a timely manner. (2) Hatching management: 35 days after the broodstock enter the mating pond, place a perforated plate in the mating pond to hide and collect the newly hatched seedlings; (3) Management of shrimp fry cultivation: After cleaning the cultivation pond or cultivation barrel, fill it with water to a depth of 15-20 cm and spray it with probiotics. After shading 30%-40% of the surface of the pond or barrel, ensure that the cultivation pond or cultivation barrel meets the cultivation conditions of red claw crayfish. Use a 60-mesh soft net to scoop up shrimp fry from the mating pond using a perforated plate on the habitat layer to collect the fry, transfer them to the shrimp fry cultivation pond or cultivation barrel, and then cultivate them. Observe the feeding situation of the shrimp fry every day by checking the food filling in their intestines.

[0010] Furthermore, in step (1), the number of caves in the cave structure accounts for 50%-60% of the number of broodstock in the mating pool; the number of shading panels placed accounts for 20%-25% of the pool area; in step (2), the number of habitat layer perforated panels placed is 2 / m 2 -4 pieces / m 2 .

[0011] Furthermore, the suitable area of ​​the broodstock mating pond is 20-30m 2 , use factory-made cement pool or sand bottom pool, which is equipped with aeration system, water inlet system, drainage system, temperature control system, and the suitable pool height is 60-80cm.

[0012] Furthermore, the selection criteria for the broodstock are: male shrimps weigh more than 90g / tail, female shrimps weigh more than 60g / tail, and the size of male shrimps does not exceed 30g of female shrimps; and the ratio of female shrimps to male shrimps in the mating pool is 3-2:1; the breeding density of broodstock in the mating pool is 12-15 tails / m 2 .

[0013] Furthermore, the cultivation conditions of the broodstock are as follows: natural light during the day, water temperature of 22-30°C, pH value of 7.2-8.6, ammonia nitrogen ≤0.5mg / L, subsalt ≤0.1mg / L, total hardness ≥80mg / L, dissolved oxygen ≥5mg / L; watering with lactic acid bacteria or bacillus every week to maintain the bacterial phase of good varieties in the water; feeding white shrimp compound feed with 41% crude protein twice a day, 7:00-8:00 in the morning and 6:00-7:00 in the afternoon, respectively, the daily feeding amount accounts for 2% of the body weight of the broodstock, the morning and evening feeding mass ratio is 3:7, after feeding the compound feed for 2 days, feeding shellfish meat and cooked soybeans at a mass ratio of 1:1 on the third day, the daily feeding amount accounts for 6% of the body weight of the broodstock, and the morning and evening feeding time points and ratios are consistent with the compound feed.

[0014] Furthermore, in step (1), the broodstock need to be disinfected before entering the mating pool. The disinfection method is to use 20 ppm bleaching powder, then soak in 3-5‰ salt water without residual chlorine for 15 minutes and then put into the mating pool.

[0015] Furthermore, during the intensive cultivation of broodstock in step (1), the mating pool uses micro-convective water, and the water convects and rotates in the pool.

[0016] Furthermore, 20% of the shrimp fry culture water is water from the parent shrimp mating pool. After the mating pool water is extracted, the water level of the mating pool is replenished to the original water level in time, and each time new water is added, 5ppm of sclerophylline is sprayed throughout the pool to increase the hardness of the water.

[0017] Furthermore, in step (3), the water quality management of the cultivation pool or cultivation barrel is to alternately spray water with lactic acid bacteria and Bacillus every day within 7 days after the start of cultivation, which is very critical for controlling the nitrite concentration in the water body. After 7 days, 5% of new water is added every 2 days.

[0018] Furthermore, the cultivation density in step (3) is 300-500 fish / m 2 .

[0019] Furthermore, the feeding management of the red claw crayfish seedlings in step (3) is as follows: when the seedlings are just hatched, they are fed once a day for the first 7 days, at 6:00-7:00 p.m., by mixing 42% crude protein white shrimp feed powder, egg yolk and cooked soy milk in a mass ratio of 4:2:2 and feeding them at a feeding rate of 1-1.5 g / m 2 After 7 days of cultivation, feed twice a day, at 7:00-8:00 a.m. and 6:00-7:00 p.m., mix 42% crude protein Vannamei shrimp feed No. 0, egg yolk and cooked soy milk in a mass ratio of 6:2:2 and feed at a feeding rate of 2-2.5 g / m 2 The feeding ratio between morning and evening is 3:7, until the shrimp fry are cultivated to be 1.5-2cm in length.

[0020] Compared with the existing technology, the effects and advantages of the present invention are: 1. The brick-built cave structure and sunshade of the broodstock mating pool used in the present invention can provide sufficient habitat space for broodstock, reduce the fight between broodstock and broodstock, and thus reduce the elimination rate of broodstock; not picking out broodstock does not affect the fertilized eggs of broodstock, and saves hatching space for broodstock.

[0021] 2. The perch plate used in the present invention provides a habitat for newly hatched seedlings, avoiding residual food from the parent shrimps, and at the same time facilitates timely seedling collection operations and provides a habitat for shrimp seedling cultivation, greatly improving the survival rate and growth rate of shrimp seedling cultivation. The mating pool uses micro-convection water to simulate natural living conditions, and at the same time feeds are fed with compound feed plus animal and plant baits to ensure the nutritional needs of the parent shrimps during mating and egg holding, and improve the mating rate and egg holding amount. Compared with the soil pond breeding and hatching method, it reduces the impact of weather and water temperature, especially high temperature in summer, on the mating of parent shrimps and egg holding shrimps, and improves the mating rate of parent shrimps and the hatching rate of egg holding shrimps. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1Brick-built cave structures for the mating pools of broodstock in the large-scale nursery facilities for red claw crayfish; Figure 2 It is a sunshade for the mating pool of broodstock in the large-scale breeding facilities of red claw crayfish; Figure 3 It is a perforated plate for shrimp fry habitat in the supporting facilities for large-scale red claw crayfish breeding.

[0023] In the picture, 1. Bricks, 2. Caves, 3. Corner supports, 4. HDPE black film, 5. Single-layer gusset plate, 6. Aluminum wire, 7. Gusset plate holes. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the scope of protection claimed by the present invention is not limited to the scope described in the examples.

[0025] The large-scale seedling raising device of red claw crayfish of the present invention comprises a cave structure and a sunshade plate made of bricks in a mating pool, and a habitat layer-type hole plate for collecting and raising seedlings.

[0026] Among them, the brick cave structure ( Figure 1 The double-layer structure is made of prefabricated cement bricks 1, with a size of 23.5×10.5×4.5cm, neatly stacked into a double-layer cave structure. The size of cave 2 is (6-8)×(6-8)×52.5cm. Each cave can accommodate 2 shrimps. The number of caves 2 accounts for 50-60% of the number of broodstock in the mating pool. visor ( Figure 2 The frame size is 100×60×10cm, which is connected by DN20 PVC plastic pipes. Each of the four corners of the frame has a 10cm high support angle 3, which is supported by a PVC pipe. The 100×60cm plane of the frame is covered and fixed with HDPE black film 4 to form a sunshade. The number of sunshades placed accounts for about 20%-25% of the pool area.

[0027] Shrimp fry habitat layer hole plate ( Figure 3 ) is a homemade habitat for shrimp seedling collection and cultivation, made of white or gray PVC ceiling gussets, and the production steps are: select a single-layer gusset 5 with a specification of 25 cm in width, 0.9 cm in thickness, and a hole specification of about 0.7×0.7 cm, and cut the gusset 5 evenly into small sections, each section has a specification of 30×6 cm, and each section has 25 holes; after every 6-8 small sections are neatly stacked according to the front, holes are drilled at both ends at a distance of 2 cm and 4 cm from the edge respectively, which are the gusset holes 7, and are tied and fixed with aluminum wires 6 to form a layered perforated plate system. Example 1

[0028] A method for large-scale breeding of red claw crayfish comprises the following steps: (1) Broodstock cultivation: Select three cement pools with a flat bottom of 5×4×0.8 meters, equipped with an aeration system, water inlet system, drainage system, and temperature control system, and set up brick cave structures and sunshades. There are 124 caves and 8 sunshades. After cleaning the cement pool before water inlet, use groundwater to fill the water to 40cm; after water inlet, use 20g of lactic acid bacteria + 50g of brown sugar to spray the entire pool. One day after spraying, select 14-month-old broodstock, male shrimp 90g-100g / tail, female shrimp 60g-70g / tail, male shrimp size does not exceed 30g female shrimp; 240 broodstock are placed in each pool, including 180 female shrimp and 60 male shrimp. The mating pool is exposed to natural light during the day. The water temperature is controlled at 22-26℃ every day, with a daily temperature difference of ±1℃, a pH value of 7.2-8.6, ammonia nitrogen ≤0.5mg / L, subsalt ≤0.1mg / L, total hardness ≥80mg / L, dissolved oxygen ≥5mg / L, and the water quality is observed and tested every day. Lactobacillus or Bacillus is sprayed with water every week to maintain the good bacterial phase in the water and decompose the residual bait and feces at the bottom of the pond in time. The shrimps are fed with a 41% crude protein feed twice a day, once in the morning and once in the evening, at 7:00-8:00 in the morning and 6:00-7:00 in the evening, respectively. The daily feeding amount accounts for 2% of the body weight of the shrimps, and the feeding ratio of morning and evening is 3:7, and the whole pond is fed evenly. After feeding the feed for 2 days, shellfish meat and cooked soybeans are fed at a mass ratio of 1:1 on the third day, and the daily feeding amount accounts for 6% of the body weight of the shrimps. The feeding time and ratio are consistent with the feed. Observe the feeding habits of the broodstock daily and adjust the feeding amount in time.

[0029] (2) Hatching management: The hatching pond and the mating pond are the same pond, and hatching management is carried out on the basis of intensive cultivation management of broodstock. The broodstock mating pond has enough brick cave structures, and the broodstock can hide in the cave structures after mating and spawning; 35 days after the broodstock enter the mating pond, the shrimp fry habitat layer perforated plates are placed in the mating pond in a vertical direction, with a number of 2 / m 2 , used for hiding and collecting newly hatched seedlings. Other daily management is the same as that of broodstock cultivation.

[0030] (3) Shrimp fry cultivation: A. The cultivation barrel adopts a glass fiber reinforced plastic barrel with a radius of 1m, a depth of 0.8m and a flat bottom, and is equipped with a habitat layer perforated plate, the number of which is 8. Water is added one day before the seedlings are released. After the cultivation barrel is cleaned before water is added, 80% groundwater + 20% mating pool water is used to add water to the water level of 20cm. After water is added, 3g of lactic acid bacteria + 7.5g of brown sugar are sprinkled on the whole barrel; during the day, the shading net is covered on the barrel surface, and the area of ​​the shading net accounts for 30% of the barrel surface area; the water temperature is 22-26℃, the pH value is 7.2-8.6, ammonia nitrogen ≤0.5mg / L, subsalt ≤0.1mg / L, total hardness ≥80mg / L, dissolved oxygen ≥5mg / L, and the water quality is observed and tested every day; within 7 days from the beginning of cultivation, lactic acid bacteria and Bacillus are alternately sprinkled every day; about 5% of new water is added every 2 days within 7 days.

[0031] B. Seedling collection: Every day, 3 perforated perforated plates are scooped up from each mating pool with a scoop net made of soft net. When the number of seedlings on each plate reaches about 10 on average, the seedlings are collected from the perforated perforated perforated plate system with a scoop net. Seedlings are collected every 3 days. On the same day, the seedlings from the 3 mating pools are collected into a shrimp seedling cultivation bucket for cultivation. The cultivation density is 400-500 per cubic meter. 2 ; C. Feeding management: When the seedlings are just hatched and the body length is about 0.5cm, they start feeding every day. For the first 7 days, feed once a day at 6:00-7:00 pm. Use 42% crude protein white shrimp feed powder, egg yolk and cooked soy milk. Mix the three in a mass ratio of 4 (dry weight): 2 (wet weight): 2 (wet weight) and feed them evenly. The feeding amount is 1-1.5g / m 2 After 7 days of cultivation, feed twice a day, at 7:00-8:00 a.m. and 6:00-7:00 p.m., with a mixture of 42% crude protein white shrimp feed No. 0, egg yolk and cooked soy milk, mixed evenly in a mass ratio of 6 (dry weight): 2 (wet weight): 2 (wet weight) and fed at a feeding rate of 2-2.5 g / m 2 , until the shrimp fry are cultivated to be 1.5-2cm in length; observe the feeding situation of the shrimp fry by checking the food filling of their intestines every day.

[0032] The experimental period was 70 days. On the 35th day, the entire breeding pond was drained, and the number of broodstock and gravid shrimps were counted. Then all broodstock were returned to the mating pond, and water was added back to the original water level. After 35 days, the number of collected seedlings was counted. The experimental results are as follows: the total number of broodstock in the three mating ponds was 669, with a survival rate of 92.9%, the total number of gravid shrimps was 391, with an egg holding rate of 72.4%, and a total of 127,075 gravid shrimps were collected. Example 2

[0033] A method for large-scale breeding of red claw crayfish comprises the following steps: (1) Broodstock cultivation: Select three cement pools with a flat bottom of 5×4×0.8 meters, equipped with an aeration system, water inlet system, drainage system, temperature control system, and brick cave structures and sunshades. There are 154 caves and 8 sunshades. After cleaning the cement pool before water inlet, use groundwater to fill the water to 40cm. After water inlet, sprinkle the entire pool with 20g of lactic acid bacteria + 50g of brown sugar. One day later, select 12-month-old broodstock, male shrimp 110-120g / tail, female shrimp 80-90g / tail, male shrimp size does not exceed 30g of female shrimp; 300 broodstock are placed in each pool, including 200 female shrimp and 100 male shrimp. The mating pool is exposed to natural light during the day; the water temperature is controlled at 26-29℃ every day, with a daily temperature difference of ±1℃, a pH value of 7.2-8.6, ammonia nitrogen ≤0.5mg / L, subsalt ≤0.1mg / L, total hardness ≥80mg / L, dissolved oxygen ≥5mg / L, and the water quality is observed and tested every day; lactic acid bacteria or bacillus are sprayed into the water every week to maintain the good bacterial phase in the water and decompose the residual bait and feces at the bottom of the pool in time; white shrimp with 41% crude protein are fed every day Feed compound feed twice, once in the morning and once in the evening, at 7:00-8:00 in the morning and 6:00-7:00 in the evening respectively. The daily feeding amount is 2% of the body weight of the broodstock. The feeding ratio of morning and evening is 3:7, and the whole pond is fed evenly. After every 2 days of compound feed, feed shellfish meat and cooked soybeans at a mass ratio of 1:1 on the third day. The daily feeding amount is 6% of the body weight of the broodstock. The feeding time and ratio are consistent with the compound feed. Observe the feeding situation of the broodstock daily and adjust the feeding amount in time.

[0034] (2) Hatching management: exactly the same as in Example 1.

[0035] (3) Shrimp fry cultivation: A. The cultivation pool uses a 3×2×0.8 cement pool with a flat bottom, and is equipped with 12 perforated plates of habitat layer, evenly arranged at the bottom of the pool. Water is added one day before stocking. After the cultivation pool is cleaned before water addition, 80% groundwater + 20% mating pool water is added to the water level of 20cm. After water addition, 6g of lactic acid bacteria + 15g of brown sugar are sprayed throughout the pool; during the day, the pool surface is covered with a shading net, and the area of ​​the shading net accounts for 30% of the pool surface area; the water temperature is 26-29℃, the pH value is 7.2-8.6, ammonia nitrogen ≤0.5mg / L, subsalt ≤0.1mg / L, total hardness ≥80mg / L, dissolved oxygen ≥5mg / L, and the water quality is observed and tested every day; within 7 days from the beginning of cultivation, lactic acid bacteria and Bacillus are alternately sprayed every day; about 5% of new water is added every 2 days for 7 days.

[0036] B. Seedling collection: Every day, 3 perforated perforated plates are scooped up from each mating pool with a scoop net made of soft net. When the number of seedlings on each plate reaches about 10 on average, the seedlings are collected from the perforated perforated perforated plate system with a scoop net. Seedlings are collected every 3 days. On the same day, the seedlings from the 3 mating pools are gathered into one shrimp seedling cultivation pool for cultivation; the cultivation density is 300-400 per square meter. 2 ; C. Feeding management: exactly the same as in Example 1.

[0037] The experimental period was 70 days. On the 35th day, the entire breeding pond was drained, and the number of broodstock and gravid shrimps were counted. Then all broodstock were returned to the mating pond, and water was added back to the original water level. After 35 days, the number of collected seedlings was counted. The experimental results are as follows: the total number of broodstock in the three mating ponds was 816, with a survival rate of 90.7%, the total number of gravid shrimps was 442, with an egg-gravidity rate of 73.7%, and a total of 148,513 gravid shrimps were collected.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A large-scale seedling raising device for red claw crayfish, characterized in that: The device comprises a brick cave structure and a sunshade arranged in a mating pool for broodstock, and a habitat layer hole plate arranged in the mating pool for collecting and cultivating shrimp fry.

2. The large-scale seedling raising device of red claw crayfish according to claim 1, characterized in that: The brick-built cave structure is a double-layer structure, which is formed by neatly stacking bricks with a size of 23.5 cm×10.5 cm×4.5 cm; the size of the cave is (6-8) cm×(6-8) cm×52.5 cm, and each cave can accommodate 2 shrimps.

3. The large-scale seedling raising device of red claw crayfish according to claim 1 is characterized in that: The frame specification of the sunshade is 100cm×60cm×10cm. The frame is connected by PVC plastic pipes. Each of the four corners of the frame has a supporting angle. The frame is covered and fixed with a HDPE black film to form a sunshade.

4. The large-scale seedling raising device for red claw crayfish according to claim 1, characterized in that: The steps for making the habitat layer perforated plate are as follows: select a single-layer gusset plate with a width of 25 cm-30 cm, a thickness of 0.9 cm-1 cm, and a hole size of about 0.7 cm×0.7 cm, cut the gusset plate evenly into small sections, each section has a size of (25-30) cm×6 cm, and each section has 25 holes; after stacking every 6-8 sections neatly according to the front side, drill holes at both ends at a distance of 2 cm and 4 cm from the edge respectively, and use aluminum wire to penetrate the holes and bind them to fix.

5. A method for large-scale breeding of red claw crayfish, characterized in that: The method utilizes the large-scale seedling raising device according to claim 1, and specifically comprises the following steps: (1) Selection and intensive cultivation of broodstock: Before cultivation, a brick cave structure and sunshade are set up in the broodstock mating pool. After cleaning the mating pool, water is added to a depth of 40 cm and probiotics are sprayed throughout the pool. Broodstock aged 12-16 months are selected and placed in the mating pool for intensive cultivation. The feeding situation of the broodstock is observed daily and the feeding amount is adjusted in a timely manner. (2) Hatching management: 35 days after the broodstock enter the mating pond, place a perforated plate in the mating pond to hide and collect the newly hatched seedlings; (3) Management of shrimp fry cultivation: After cleaning the cultivation pond or cultivation barrel, fill it with water to a depth of 15-20 cm and spray it with probiotics. After shading 30%-40% of the surface of the pond or barrel, ensure that the cultivation pond or cultivation barrel meets the cultivation conditions of red claw crayfish. Use a 60-mesh soft net to scoop up shrimp fry from the mating pond using a perforated plate on the habitat layer to collect the fry, transfer them to the shrimp fry cultivation pond or cultivation barrel, and then cultivate them. Observe the feeding situation of the shrimp fry every day by checking the food filling in their intestines.

6. The large-scale seedling raising method according to claim 5, characterized in that: In step (1), the number of caves in the cave structure accounts for 50%-60% of the number of broodstock in the mating pool; the number of shading panels placed accounts for 20%-25% of the pool area; in step (2), the number of habitat layer perforated panels placed is 2 / m 2 -4 pieces / m 2 .

7. The large-scale seedling raising method according to claim 5, characterized in that: The selection criteria for the broodstock are: male prawns weigh more than 90g / tail, female prawns weigh more than 60g / tail, and the size of male prawns does not exceed 30g of female prawns; and the ratio of female prawns to male prawns in the mating pool is 3-2:1; the breeding density of broodstock in the mating pool is 12-15 prawns / m 2 .

8. The large-scale seedling raising method according to claim 5, characterized in that: The culture conditions of the broodstock are as follows: natural light during the day, water temperature of 22°C-30°C, pH value of 7.2-8.6, ammonia nitrogen ≤0.5mg / L, subsalt ≤0.1mg / L, total hardness ≥80mg / L, dissolved oxygen ≥5mg / L; watering with lactic acid bacteria or bacillus every week to maintain the bacterial phase of good species in the water; feeding the white shrimp compound feed with 41% crude protein twice a day, at 7:00-8:00 in the morning and 6:00-7:00 in the afternoon, respectively, the daily feeding amount accounts for 2% of the body weight of the broodstock, and the mass ratio of morning and evening feeding is 3:

7. After feeding the compound feed for 2 days, shellfish meat and cooked soybeans are fed at a mass ratio of 1:1 on the third day, and the daily feeding amount accounts for 6% of the body weight of the broodstock. The feeding time and ratio of morning and evening feeding are consistent with those of the compound feed.

9. The large-scale seedling raising method according to claim 5, characterized in that: The culture density in step (3) is 300 fish / m 2 -500 tails / m 2 .

10. The large-scale seedling raising method according to claim 5, characterized in that: The feeding management during the cultivation of red claw crayfish seedlings in step (3) is as follows: when the seedlings are just hatched, they are fed once a day for the first 7 days, at 6:00-7:00 p.m., by mixing 42% crude protein vannamei compound feed powder, egg yolk and cooked soy milk in a mass ratio of 4:2:2 and feeding them at a feeding rate of 1 g / m 2 -1.5g / m 2 After 7 days of cultivation, feed twice a day, at 7:00-8:00 a.m. and 6:00-7:00 p.m., mix 42% crude protein vannamei shrimp feed No. 0, egg yolk and cooked soy milk in a mass ratio of 6:2:2 and feed at a feeding rate of 2 g / m 2 -2.5g / m 2 The feeding ratio between morning and evening is 3:7, until the shrimp fry are cultivated into 1.5cm-2cm in length.

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