Key Technical Points for Farming Crayfish in Cement Pools

 There are many ways and methods to farm crayfish. As far as the editor knows, these include: farming crayfish in cement pools, farming crayfish in rice paddies, farming crayfish in lotus root fields, and so on. As people's farming techniques are constantly being perfected and improved, more and more new farming techniques are constantly emerging.

Techniques for Farming Crayfish in Cement Pools  

1. Preparation of breeding pools: Build several small pools, each with an area of about 4 sq m and a depth of 70 cm. Before stocking brood crayfish, disinfect each square meter of the breeding pool thoroughly with about 200 g of quicklime. Newly built cement pools should be dealkalized first and then disinfected.  

The water depth in cement pools is generally kept at 50-60 cm. Build artificial burrows on the pool bottom with asbestos tiles and red bricks. Erect shade cloth above the cement pool. Stock water hyacinth in the pool, covering 2/3 of the water surface. Equip the pool with corresponding aeration facilities.  

2. Selection of brood crayfish: Select brood crayfish generally in June-August. The brood crayfish are required to be over 40 g each, healthy in constitution, with complete appendages, bright in color, and free of disease and injury on the body surface.  

3. Stocking of brood crayfish: For brood crayfish transported over long distances, before stocking, first soak the brood crayfish in the pool water for 3-5 minutes, then place them at the pool edge for 2-3 minutes. Repeat this 2-3 times so that the brood crayfish absorb enough water, then slowly release them into the pool along the pond's perimeter. Stock 40 brood crayfish per square meter, with a female-to-male ratio of 1:1. At the same time, the stocked brood crayfish should be uniform in size.  

4. Brood crayfish cultivation: Before reproduction, brood crayfish need enhanced cultivation to supplement the shrimp's nutrition and promote gonadal development. Generally, feed high-animal-protein feed (such as fish mince, fish viscera and animal offal), together with plant-based feed (such as soybean meal, bran, etc.). The ratio of animal feed to plant feed is 1:1 or 3:2. Generally, feed once a day at around 5 p.m., with a feeding rate of 3-5%.  

5. Water quality management: Change the water in the breeding pool once every 3-5 days. If the water quality of the crayfish pool is very poor, drain the pool water and clean the crayfish pool. When the water body is short of oxygen, turn on the aerator in time to increase oxygen.  

6. Fertilization and hatching: After enhanced cultivation, brood crayfish mate in September when the water temperature reaches above 18°C, and begin to lay eggs successively around mid-October. When the water temperature is 18-20°C, the incubation period of fertilized eggs is 30-40 days; when the water temperature is 25°C, it takes only 15-20 days. When a large number of juvenile crayfish appear in the breeding pool, collect the seedlings in time.  

7. Juvenile crayfish cultivation: Transfer the collected juvenile crayfish to the juvenile crayfish cultivation pool in time. The juvenile crayfish cultivation pool is best a cement pool with an area of 20-40 sq m and a water depth of 1 m; alternatively, an earthen pool with an area of 1-3 mu, a slope ratio of 1:2 and a water depth of 0.5-1 m may be chosen. Apply 500 kg of decomposed human and livestock manure per mu to cultivate natural feed. Stock a certain number of aquatic plants (alligator weed, water hyacinth, etc.) in the pool to provide juvenile crayfish with places to rest, molt and hide.  

Choose a sunny morning or a cloudy day to stock juvenile crayfish, at 150-230 per square meter. In the first week after stocking, feed soybean milk, 3-4 times a day; in the second week, mainly feed animal feed such as small fish and shrimp, meat of snails and mussels, earthworms and silkworm pupae, appropriately combined with a paste feed made by mixing and grinding corn, wheat and fresh tender plant stems and leaves, feeding once each in the morning and evening, with the evening feeding accounting for 70% of the whole day's amount. The daily feeding amount in the early stage is 250-400 g per 10,000 juvenile crayfish, and afterward feed about 10% of the crayfish body weight in the pool. During the cultivation process, change the water once every 7-10 days, changing 1/3 each time; about every 15 days, slake 20 g of quicklime per cubic meter of water and splash the slurry evenly over the whole pool once.  

After 25-30 days of cultivation and 5-8 molts of growth, juvenile crayfish can reach a body length of 3 cm. The juvenile crayfish can be divided and transferred to earthen pools in April of the following year for conventional farming.  

Preparation for Stocking Crayfish  

1. Thoroughly clear the pool: 20-30 days before stocking juvenile and young crayfish, drain the pool water, remove excess sludge, repair the pool ridges, and use 75 kg of quicklime per mu or drugs such as bleaching powder and bleaching powder concentrate to thoroughly clear and disinfect the pool.  

2. Apply sufficient base fertilizer: Apply 500-600 kg of decomposed livestock and poultry manure per mu to cultivate rotifers and cladoceran and copepod plankton, providing suitable bait for juvenile and young crayfish.  

3. Plant aquatic plants well: Plant aquatic plants such as Hydrilla verticillata, Potamogeton malaianus and Elodea in the farming pool, covering 2/3 of the crayfish pool area. At the same time, set up netting, or place bamboo tubes, plastic tubes, etc., to provide places for the red swamp crayfish to rest, molt and hide. 

Timely Harvesting of Crayfish  

1. Ground cage net harvesting: Make the crayfish harvesting net into a ground cage. Each ground cage is about 5 m long, and each grid has barbs on both sides at intervals; shade netting is woven above the cage, and the two ends of the ground cage are respectively enclosed into circles. Ground cage nets with knots are better. Put the ground cage at the edge of the crayfish pond every morning or afternoon, and put in fish, chicken intestines and other items with a strong fishy smell as bait. Toward evening, when the crayfish come out to seek food, they smell the strange odor, follow the smell, and bump into the cage. With netting blocking above the cage, they cannot climb up, so they look everywhere for an entrance and drill into the cage. Once in the cage, the crayfish slide toward the depth of the cage and become crayfish in the cage. This harvesting method is suitable for harvesting crayfish in relatively deep pond water.  

2. Hand dip net harvesting: Tie the upper part of the crayfish net into a square shape, and leave a barbed cone-shaped funnel below. Along the edge of the crayfish pond or where aquatic plants grow densely, keep driving with a pole. The crayfish enter the square dip net, and when the net is lifted, the crayfish are caught. This harvesting method is suitable for places where crayfish are dense.  

3. Dry pond harvesting: Pump the water out of the pond, and the crayfish will appear on the pond bottom. Pick them up by hand and catch them to your heart's content.  

What Advantages Does Farming Crayfish Have  

1. Large market potential: The market demand for crayfish is very large. This tight market supply-demand relationship gives the crayfish industry relatively high economic benefits and broad development prospects, and there is no problem with sales.  

2. Low farming difficulty: Crayfish have strong adaptability to the environment, few diseases, and tolerance to low oxygen. They can be farmed at high density in small water bodies in ponds, and can also reproduce naturally in various water bodies such as rivers and ditches, lakes, rice paddies and swamps. The farming techniques are simple.  

3. Low farming cost: Crayfish have omnivorous feeding habits, bait is easy to obtain, and at low stocking density no special feed is needed. They grow relatively fast, have high yield, high energy conversion rate, low farming cost and good benefits.  

4. Short farming cycle: Crayfish can generally be grown to market size after about 2 months of farming. Through the technical plan of harvesting the large and leaving the small, a cyclic farming method can be adopted. It belongs to a farming model of one-time stocking and year-round benefits.

Crayfish currently fetch a very good price on the market, especially in the late-night snack industry, where crayfish are deeply loved by everyone. We all know that now, especially some young people, very much like to go out at night. Gathering three or five friends at night to eat late-night snacks and chat about life is a very pleasant thing.