CATDOLL : CATDOLL: Does anyone know how to breed crayfish?

Crayfish have strong adaptability to the environment and can grow in various water bodies such as lakes, ponds, rivers, and rice fields.

The water source should be sufficient, the water depth should be about 1 meter. The pond should have sufficient water source, good water quality, convenient water inlet and drainage, and the area is generally 3 mu to 5 mu.

The bank of the pond should have a certain slope, and to prevent crayfish from digging holes and escaping, the width of the bank should be more than 1.5 meters, and a 0.5-meter-high, smooth-walled anti-escape wall or anti-escape board should be set around the bank.

Crayfish is a freshwater economic shrimp, which is widely popular because of its delicious meat. It has an absolute competitive advantage in the local ecological environment due to its omnivorous nature, fast growth rate and strong adaptability.

Crayfish breeding technology

The first is to create a good growth environment for lobsters. Lobsters are crustaceans, similar to crabs, with a pair of particularly developed claws. They have the habit of digging holes to live in, usually near the water's shore. Lobsters prefer shade and are afraid of light. They crawl out of their holes when the light is weak or dark, and sink to the bottom of the water or hide in their holes when the light is strong. According to the habits of lobsters, a 50-cm high escape-proof net can be added to the riverside to prevent lobsters from escaping. At the same time, rivers and ponds simulate the ecological environment of lobsters under natural conditions, and 10-15% of aquatic plants and shelters are shallowly planted by the pool to create an environment for lobsters to live and shed their shells, reducing cannibalism.

The impact of water quality on lobster production cannot be ignored. The quality of water directly affects the healthy growth and development of lobsters. During the breeding process, the pH value of the pond water is maintained between 7.5-8.5, and the transparency is 30-40 cm. New water should be added frequently, and quicklime solution should be sprinkled regularly to adjust the water quality and prevent diseases and molting failure.

Second, feed them properly. Lobsters will kill each other when they are hungry or have insufficient food, so the amount of feed must be sufficient. Lobsters are fed with animal and plant feed. Plant feed includes wheat, aquatic plants, rapeseed cake, etc. Animal feed includes fish, meat, and animal offal. Usually, the feeding time, feeding amount, and feeding method are determined according to the habit of lobsters hiding during the day and coming out at night and the density of shrimps in the pond. Otherwise, the feed cost will increase and the breeding efficiency will be reduced.

The third is scientific fishing. In the process of lobster farming, young shrimps can generally grow to commercial size in 60-90 days if the temperature is suitable and the feed is sufficient. The young shrimps are released in March and the rotation fishing begins around June, with the big ones being sold and the small ones being kept. By catching the big ones and keeping the small ones, and rotating the fishing and releasing, the recapture rate can be increased, and the prices can be sold at a good price, achieving the goal of high yield and high efficiency.

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Introduction to Freshwater Crayfish Breeding Technology

Freshwater lobster, scientific name Procambarus clarkii, also known as lobster, big lobster, big red shrimp. This shrimp is native to the United States and was introduced to my country from Japan during World War II. It is now widely distributed in the middle and lower reaches of the Yangtze River. This shrimp belongs to the warm tropical freshwater shrimp, with strong adaptability, high reproduction rate, miscellaneous diet, fast growth, disease resistance, high temperature resistance, low oxygen resistance, and will not die even if out of water for several hours. The shrimp meat is tender and nutritious, containing 8 essential amino acids for the human body, but with a low fat content, and contains more tropomyosin and paramyosin, and the edible part is high. It is deeply loved by domestic consumers, and the export volume is also increasing day by day. The sales and purchase prices are constantly rising, and the breeding prospects and benefits are optimistic.

Freshwater lobsters live widely in freshwater lakes, rivers, ponds, ditches and rice fields. Benthic organisms, plankton and various aquatic plants are all palatable baits, and they grow well in these waters. Young shrimps live in shallow waters or by the pond, and like to live in caves, sometimes hiding in the secluded places of gravel and aquatic plants. Usually, shrimp holes are dug in the reed-covered beach areas around the large water surface with more clay, swamps and reeds. Shrimp holes are generally round, tilted downward, up to about 30 cm deep, and the winding directions are different. Freshwater lobsters often move seasonally in their habitats. In spring, when the water temperature rises, shrimps mostly move in shallow waters; in midsummer, when the temperature is not high, they move to deep waters; in winter, they hibernate in caves. Freshwater lobsters also molt, grow and reproduce in caves to prevent being hurt. Moreover, the shrimps prefer shade and fear light, and crawl out of the caves when the light is weak or dark. In the rainy season, freshwater lobsters often climb onto land to move around. The shrimp has a strong ability to endure hunger, and can generally endure hunger for 3 to 5 days; in autumn and winter, it will not starve to death even if it does not eat for 20 to 30 days. The optimum temperature for feeding is 25 to 30 degrees Celsius; the activity decreases when the water temperature is below 15 degrees Celsius; the feeding decreases significantly when the water temperature is below 10 degrees Celsius or exceeds 35 degrees Celsius; when the water temperature is below 8 degrees Celsius, it enters the wintering period and stops feeding. The lifespan of male freshwater lobsters is generally 20 months, and the lifespan of female shrimps is 24 months.

Freshwater lobsters usually mate and lay eggs from the end of October to March of the following year. The mating time varies in different waters. If the mating is too early, the eggs are often immature, and if it is too late, the eggs are overmature and aged. The suitable water temperature for mating is 22~25℃. It is best not to catch them during the mating season, so that they can lay eggs and hatch and reproduce. Freshwater lobsters mate in spring, summer and autumn, and can lay eggs 3~4 times a year. Generally, the parent shrimps with a body length of 7~10 cm and a weight of 15~30 grams can carry 220~270 eggs, and the number of eggs varies greatly depending on the size of the individual. Under normal circumstances, the egg-carrying shrimps need a 1~2 month incubation process (i.e. embryonic development) after mating and laying eggs, which requires a lot of physical strength, so it is necessary to strengthen the nutrition and wide-sensitive cultivation of the egg-carrying shrimps. The suitable water temperature for hatching egg-carrying shrimps is 22~27℃, and the incubation time is 6~10 weeks. Before shrimp fry cultivation, ponds need to be cleaned, disinfected, and water filtered, and then organic fertilizers are applied to cultivate natural bait organisms for shrimp fry to eat. Generally, the density of juveniles in shrimp fry cultivation is 150,000 to 200,000. If the "soy milk" method is used for cultivation, the stocking density can be 160,000 to 180,000.

2. Lobster farming technology

Lobsters can be raised in ponds that are used to raise Japanese prawns. Ordinary ponds can also be used for lobster farming. The farming techniques after stocking are similar to those of Japanese prawns, including preliminary preparations, feed placement, and water quality management. However, attention should be paid to their habit of burrowing, and escape prevention measures also need to be strengthened. Lobsters have strong endurance and high production. The current market demand is also large, and the economic benefits of farming are considerable. The most common shallow water rice field farming is introduced below as an example, and other farming methods can be referenced.

3. Farming freshwater lobsters in rice fields

The yield of freshwater lobsters raised in rice fields can generally reach 400-500 kg per mu, and can reach 600 kg at high yields. Raising shrimps in rice fields can eat weeds and other aquatic organisms that consume fertilizers in the fields, which not only saves labor for weeding, but also eliminates mosquitoes and flies that harm people and livestock. In addition, shrimps move and forage constantly in rice fields, which can not only help loosen the soil, activate water, ventilate, and increase the dissolved oxygen content of field water, but also excrete a large amount of feces through metabolism, which has the effect of preserving fertilizer and increasing fat.

1. Selection of rice fields

To raise freshwater crayfish in rice fields, you must choose rice fields with sufficient water sources, that are not affected by droughts and floods, have fresh and pollution-free water, fertile soil, good water retention properties, and plenty of sunlight. Although the water quality of some mountain streams or springs is relatively poor and the water temperature is relatively low, if they can have a longer flow or pass through rice fields where shrimps are not raised and then flow into shrimp-raising rice fields, the water temperature will increase and it will also be suitable for shrimp farming.

2. Reconstruction of rice fields

In order to facilitate production management and daily feeding, the area between drainage channels is generally used as a breeding block. A circulation buffer ditch with a depth of 0.5~0.6 meters and a width of 1.0~1.2 meters is dug 0.6 meters away from the inner side of the surrounding ridges, and all the soil is turned over to the side ridges, so that the side ridges reach 0.8~1.0 meters high and 0.6~0.8 meters wide at the top. The side ridges should be compacted and the inner slopes should be flat. At the same time, a closed protective wall is surrounded by plastic film on the inner side of the ridge top. The height of the fence is 0.4~0.5 meters above the ground and buried 0.1~0.2 meters underground. Anti-escape nets should be set up at the upper and lower inlets and outlets.

In order to facilitate shallow irrigation, drying, application of fertilizers, pesticides or fishing in rice fields, shrimp ditches and shrimp ponds must be dug in shrimp-raising rice fields. Shrimp ditches can be dug after transplanting rice seedlings, and the digging method should be determined by the shape of the field, the size of the field and the direction of the drainage outlet. If the rice field is small, it can be dug into a "field" shape; if it is a long and large field, it can be dug into an inner "well" or inner "field" shape, and the width and depth of the ditch should be 0.3~0.4 meters respectively. Shrimp ponds can be dug at the intersection of shrimp ditches or at the four corners of the field, and connected to the shrimp ditches. Shrimp ponds are generally 1.0 meters square and 0.8~1.0 meters deep.

When raising shrimp in rice fields, the inlet and outlet should be well opened. The location should be selected on the earthen ridges at the two opposite corners of the rice field. During the breeding process, the water in and out of the rice field can flow smoothly. Fences should be set at the inlet and outlet to prevent shrimp from escaping.

3. Shrimp stocking

Stocking time: Whether it is the shrimp seed of the year or the broodstock with eggs, we should strive to stock them early. Early stocking can not only prolong the growth period of shrimp in the rice field, but also make full use of the large amount of natural bait resources cultivated after fertilizing the rice field. The conventional stocking time is generally in November each year or the end of March of the following year.

Stocking density: 30-40 kg of broodstock with eggs are stocked per mu of rice field. You can also wait until April or May of the following year to stock young shrimps, with 12,000 to 15,000 shrimps per mu of rice field. Note that broodstock with eggs should be directly raised in the outer ditch for wintering, and then the shrimps can be lured into the rice field for growth when the rice seedlings turn green. There are two general breeding and stocking modes:

(1) Summer stocking: mainly stocking juvenile shrimps artificially bred that year. The stocking period is from July to September. 15,000 to 20,000 juvenile shrimps are stocked per mu of shrimp ditch.

(2) Winter stocking: usually carried out in December, 10,000 to 15,000 shrimps of about 3 cm in diameter are stocked per mu of shrimp ditch. In places where conditions permit, shrimp farming can be carried out in two seasons, one season of raising green shrimps from July to October, and one season of raising freshwater lobsters from December to May to June of the following year.

4. Feeding and management

(1) Feeding: When raising shrimp in rice fields, feeding should be done at regular times, in designated areas, with fixed quantities and quality. In the early stage, feeding should be done once in the morning and afternoon; in the later stage, feeding should be done after 6 pm. The types of feed used are mostly small fish, snail meat, clam meat, earthworms, animal offal, silkworm pupae, corn, wheat and barley flour. You can also feed them an appropriate amount of plant feed, such as water hyacinth, water duckweed and water duckweed. The daily feed amount is 3-5% of the shrimp's body weight. You should always check the shrimp's eating habits. If the feed is eaten within 2-3 hours, it means that the amount of feed is insufficient and you should increase the amount of feed appropriately. If there is any left on the second day, you should reduce the amount of feed appropriately.

(2) Eliminate pests: There are many pests in rice fields, such as centipedes, snakes, water birds, eels, and water rats. In the early stage of shrimp farming, the stems and leaves of rice plants are not lush, and there are large gaps in the water surface of the field. At this time, the shrimps are also small, with weaker mobility and poorer ability to escape from pests, making them easy to be attacked by pests. At the same time, freshwater lobsters need to molt every once in a while to grow. When they are molting or just molting, they are most likely to become palatable bait for pests. At the harvest time, due to the shallow drainage of the field water, the shrimps may crawl everywhere, making them larger targets and easy to be preyed on by birds and beasts. In this regard, it is necessary to strengthen field management and drive away pests in time. In addition, after the shrimps are released, domestic ducks should be prohibited from going into the field ditches to avoid losses.

(3) Field ditch management: After shrimps are released, it is very important to manage the field ditches well.

1. The area of ​​the pond for breeding facilities should be 4 to 10 mu, 1 to 1.5 meters deep, and the slope ratio should be 1:2.5. The bottom of the pond should be flat, loam is preferred, the soil on the slope should be hard, the pond should have good water retention, and the water level should be easy to control. The water source should be sufficient and the water quality should be pollution-free. According to the pattern of high irrigation and low drainage, the water inlet and outlet channels should be built to ensure that irrigation can be carried in and drainage can be carried out. The escape ability of the crayfish is strong, so the construction of anti-escape facilities must be well done. Plastic film or calcium plastic board is usually used, and bamboo or wooden stakes are used to support the enclosure around the pond embankment to prevent escape. 2. Preparation before stocking 1. Thoroughly clean and disinfect the pond 20 to 30 days before stocking the shrimp seedlings and shrimp seeds, drain the pond water, remove excessive silt, repair the pond embankment, and use 75 kg of quicklime or bleaching powder, bleaching powder and other drugs per mu to thoroughly clean and disinfect the pond. 2. Apply sufficient basal fertilizer. Apply 500-600 kg of decomposed livestock and poultry manure per mu to cultivate rotifers, cladocerans and copepods to provide palatable food for shrimp fry and shrimp seeds. 3. Plant aquatic plants. Plant aquatic plants such as Hydrilla verticillata, Potamogeton edulis and Elodea in the pond, with the area accounting for 2/3 of the shrimp pond area. At the same time, set up nets, bamboo tubes, plastic tubes, etc. to provide habitats, molting and hiding places for Procambarus clarkii. III. Stocking of shrimp fry and shrimp seeds 1. Farming mode A variety of farming modes can be adopted. (1) Summer stocking mode. The first batch of shrimp hatched in the current year is mainly stocked. The stocking time is mid-to-late July. The size of the shrimp is more than 0.8 cm. 30,000-40,000 shrimp are stocked per mu. (2) Autumn stocking mode. The large-sized shrimp fry or shrimp seeds cultivated in the current year are mainly stocked. The stocking time is mid-August to September. For shrimp fry of about 1.2 cm in size, 25,000 to 30,000 shrimps are stocked per mu; for shrimp seedlings of 2.5 to 3 cm in size, 15,000 to 20,000 shrimps are stocked per mu. A small number of shrimps will reach the market size by the end of the year, while most of them will be caught and put on the market in June or July of the following year. The weight of commercial shrimps is 25 grams, and the yield per mu is 300 to 500 kg. (3) Winter and spring stocking mode. Generally, the stocking is carried out in December or March or April of the following year. The main purpose is to stock shrimps that do not meet the market size in the current year, with a size of 100 to 200 shrimps per kilogram, and 15,000 to 20,000 shrimps are stocked per mu. After winter and spring breeding, they will be caught and put on the market in June or July. The weight of commercial shrimps can reach 30 grams, and the yield per mu is 400 to 500 kg. 2. Seedling quality The quality requirements of shrimp fry and shrimp seedlings are: (1) Uniform size. The size of juvenile shrimps is above 0.8 cm, and the size of shrimp seedlings is about 3 cm. The size of shrimp fry and shrimp seedlings stocked in the same pond should be consistent, and they should be fully stocked at one time. (2) Strong physique, complete appendages, free of disease and injury, strong vitality. (3) Shrimp seedlings and shrimps are all artificially cultivated. If they are wild shrimps, they should be domesticated for a period of time before being released to avoid fighting and killing each other. 3. Precautions: (1) In winter, stocking should be carried out on a sunny morning, and in summer and autumn, stocking should be carried out on a sunny morning or on a rainy day to avoid exposure to the sun. (2) Before stocking, the shrimps should be bathed in 3% to 5% salt water for 10 minutes to kill parasites and pathogens. (3) Shrimp seeds purchased from other places should be slightly processed before stocking because they have been out of water for a long time. Soak the shrimp seeds in the pond water for 1 minute, lift them up and set them aside for 2 to 3 minutes, and then soak them for 1 minute. Repeat this 2 to 3 times to allow the shrimps to absorb enough water on their body surface and gill cavity before stocking to improve the survival rate. (4) In ponds where crayfish are raised, some silver carp and bighead carp should be mixed appropriately to improve water quality and make full use of bait resources. 4. Scientific feeding Crayfish have a mixed diet and are quite greedy. In feeding, the following three points should be grasped. 1. According to the nutritional needs of Crayfish at the same growth and development stage, make a good combination of feed and feeding. In the juvenile and young shrimp stages, Crayfish feed on rotifers, cladocerans, copepods and aquatic insect larvae, while in the adult shrimp stage, they feed on animal feed and plant feed. After the shrimp fry and shrimp seeds are released, fertilizers should be applied in time to improve the water quality. In the rapid growth stage of Crayfish from August to October, feed more bran, bean cakes and green feed, and feed animal feed appropriately. In November and December, before Crayfish hibernates, feed mainly animal feed. 2. Feed according to the living habits and feeding characteristics of Crayfish. Crayfish mostly move around at night to find food, and have the habit of competing for food and being greedy. Feeding should be done once in the morning and afternoon every day, with the afternoon being the main feeding amount, accounting for 70% of the total daily feeding amount; adopt a fixed-quality, quantitative and regular feeding method, feed enough and evenly, ensure that every shrimp is full, and avoid competing for food. 3. Feed reasonably according to the weather, water quality changes and shrimp activity and feeding conditions. The suitable water temperature for the growth of Crayfish is 20-32℃. From August to October, Crayfish has a large food intake. The daily feeding amount can be arranged at 6%-10% of the body weight of the shrimp in the pond. Dry feed or compound feed is coordinated at 2%-4%, and it can be appropriately increased or decreased according to the weather, water quality conditions and shrimp activity and foraging conditions. In continuous rainy weather or when the water quality is too concentrated, you can feed less, and feed more appropriately when the weather is fine; feed less when a large number of shrimps molt, and feed more after molting; feed less during the shrimp disease season, and feed more when the growth is normal. It is necessary to let the shrimp eat well and reduce waste and improve feed utilization. V. Daily Management 1. Establish a patrol inspection system. Patrol the pond every day and take timely countermeasures when abnormalities are found. 2. Regulate water quality. Keep the dissolved oxygen content in the shrimp pond above 5 g/L, pH value 7-8.5, and transparency about 40 cm. Change the water every 15-20 days, and change 1/3 of the water each time. Sprinkle quicklime water every 20 days, and use 10 kg of quicklime per mu each time. Keep the water level stable and not fluctuate. 3. Strengthen the management of habitats and molting sites. There are always more aquatic plants in the shrimp pond. It is strictly forbidden to interfere when a large number of shrimps molt. After molting, immediately add high-quality and palatable feed to prevent mutual killing and promote growth. 4. Prevent escape and disease. Strengthen inspections during the flood season to prevent shrimps from escaping. Do a good job in disease prevention and pest removal. VI. Commercial shrimp fishing and transportation 1. Fishing. It can be concentrated in June-July and November-December. First, use ground cage nets, hand nets and other tools to catch, and finally catch in dry ponds. You can also catch the big ones and leave the small ones, and fish all year round. 2. Transportation. Commercial shrimps are usually transported dry in foam plastic boxes, or they can be shipped in plastic bags or refrigerated trucks. Keep the shrimps moist during transportation and do not squeeze them to increase the survival rate during transportation. China Animal Husbandry Street www.xumuj.com

Pond Preparation

The pond should be 8-10 mu, with sufficient water source, convenient water inlet and outlet, 1.5 meters deep, flat bottom and less silt. Before cleaning the pond, add 10 cm of water, use 100 kg of quicklime slurry per mu and sprinkle it all over the pond, and add 30 cm of water after 10 days. Plant aquatic plants such as Hydrilla verticillata, Elodea, and aquatic flowers before stocking shrimp fry, and the coverage area of ​​aquatic plants accounts for 40%-60% of the pond area. After planting aquatic plants, apply 15 kg of phosphorus fertilizer or 150-200 kg of decomposed organic fertilizer per mu.

Seedling placement

The shrimp fry are required to be strong, with complete appendages, and free of disease and injury. The shrimp fry released in the same pond are required to be of consistent specifications. They are generally released in December or March-April of the following year, with 100-200 crayfish fry/kg and 50 kg of seed per acre.

Feeding

The method of feeding is to combine plant feed with animal feed. The plant feed mainly includes corn, wheat, bran, taro, pumpkin, etc., and the animal feed mainly includes pig blood, fish intestines, small fish, etc. The daily feeding amount of crayfish generally accounts for 6%-7% of the total weight of the shrimp in the pond, and the crayfish are fed twice a day.

Daily Management

The transparency of the water body is maintained at 25-30 cm. In the early stage of breeding, new water is added and conditioned every 5 days. In the high temperature period from July to August, the water is changed once a week and the water depth is maintained at 1.2-1.5 meters. 10 catties of quicklime is applied per mu once a month to promote the growth and molting of young shrimps. The pond is inspected once in the morning, noon and evening every day to observe the eating and growth of crayfish.

Disease control

Adhere to the principle of "prevention first, prevention is better than cure". In addition to regularly using quicklime to disinfect the pond, microbial preparations should be applied regularly according to water quality and crayfish activity to create a good environment and maintain normal growth of crayfish.

Catch and market

Around June, crayfish can be caught in time according to market demand and growth specifications.