How to Build a Better Crayfish Farming Pond

Before raising crayfish, the first thing we need to do is build a farming pond and create an environment suitable for crayfish growth and survival. Only in this way can we greatly increase farming yields and effectively reduce the prevention of certain diseases during the crayfish farming process.

How to Build a Crayfish Farming Pond

1. Site Selection

The size of the breeding site should be determined according to the scale of production. It requires an adequate water source, good water quality, convenient drainage and irrigation, fresh air, a quiet environment, and freedom from natural and human disturbances, achieving the “three connections” (road access, electricity, and communications).

2. Pond Construction

Breeding facilities require the following types of ponds:

① Broodstock pond. Used for cultivating and reserving broodstock. Generally, each pond has an area of 60-80 sq m. During large-scale production, the area can be several hundred sq m. With a large water body, the water quality is relatively stable, and the breeding results are also good.

② Spawning pond. Each pond has an area of 30-60 sq m and is used for broodstock spawning and fertilization. It should be convenient for drainage and irrigation and conducive to inspecting and catching egg-bearing crayfish.

③ Hatching and nursery pond. It should be smaller, with each pond having an area of 4-6 sq m, making it convenient for changing water, inspection and management, and batch hatching and nursery rearing.

④ Feed pond. Each pond has an area of 20-30 sq m and is used for cultivating small zooplankton.

3. Construction Requirements

The above ponds should be 0.8-1.5 m deep, installed with adjustable drainage pipes, and equipped with anti-escape facilities. The pond bottom is best made of sandy loam, or a cement bottom covered with 10-15 cm of medium-sized sand. The pond walls should be built with bricks and coated with cement on the outside, with an overhanging lip at the top of the bank to prevent escape. A frame should be embedded in the pond in advance to facilitate laying shade netting into a plastic film shed. Place enough bamboo tube sections and tile pipes around the bottom of the pond for the crayfish to hide in, and set up several bamboo pieces that also serve as feeding platforms. Cover 1/3 of the pond surface with water hyacinth for cultivation, and plant some aquatic plants on the pond bottom where possible.

Crayfish Farming Prospects  

Crayfish, scientifically known as Procambarus clarkii, have strong adaptability to the environment, few diseases, and tolerance to low oxygen. They can grow and reproduce in ponds, ditches, lakes, rice fields, swamps, and other water bodies, and can survive out of water or live in burrows for relatively long periods. They have strong tolerance to adverse environments, are convenient to transport, and have a high transport survival rate. This is unmatched by other shrimp species.  

At the same time, crayfish seedlings are easy to breed and can be self-bred and self-raised without complex equipment. The technology is simple, feed is easy to obtain, and they are suitable for artificial farming. Generally, intensive pond farming yields 400 kg per mu, with profits of more than 1600 yuan. At present, the amount of artificially farmed crayfish is small, and the market mainly relies on natural catching. Its natural resources are far from meeting the consumer demand of international and domestic markets.  

European and American countries are the main consumers of crayfish. In the United States, this shrimp is not only an important edible shrimp but also an important bait for fishing. Annual consumption is 60,000-80,000 tons, with self-sufficiency of less than 1/3. The European Union and the United States import up to 20,000 tons from China each year. Sweden is especially a fanatical consumer of crayfish, holding a 3-week crayfish festival every year. The Western European market consumes 60,000-80,000 tons of crayfish a year, while Western Europe's self-sufficiency accounts for only 20% of total consumption. 

Preparations Before Stocking Crayfish  

1. Conditions and preparation of rice fields. The area of the rice field should be large, generally from several dozen mu to over a hundred mu. The field ridges should be relatively high and able to retain a water depth of 50-80 cm. A ditch 1-1.5 m wide and 0.8 m deep should be dug along the inner edge of the field ridges. For larger fields, a “cross”-shaped or “well”-shaped ditch should also be dug in the middle, with a width of 0.5-1 m and a depth of 0.5 m. 10-15 days before stocking shrimp, use 50 kg of quicklime per mu of rice field shrimp-raising ditch, or choose other drugs, to thoroughly clean and disinfect the rearing ditch and kill wild miscellaneous fish, harmful organisms, and pathogenic bacteria.  

2. Apply sufficient base fertilizer. 7-10 days before stocking shrimp, fill the field ditch with 50-80 cm of water, then apply fertilizer to cultivate feed organisms. Generally, apply 50 kg of compound fertilizer and 50 kg of ammonium bicarbonate per mu. Farmyard manure has slow and long-lasting fertilizer effects. After application, it has no effect on the growth of crayfish and can also reduce the frequency and amount of chemical fertilizer application in the future. Therefore, if farmyard manure is available, it is best to apply farmyard manure, 1000 kg per mu, applied sufficiently at one time.  

3. Transplant aquatic plants. Plant submerged aquatic plants such as Hydrilla verticillata and Ceratophyllum demersum in the shrimp ditch, or plant water spinach and water hyacinth along the ditch edges. However, the area of aquatic plants should be controlled. Generally, aquatic plants should account for 10%-20% of the shrimp ditch area, preferably distributed sparsely rather than clustered together, which helps keep the water flow in the shrimp ditch unobstructed.  

4. Filtration and anti-escape measures. Bamboo screens, wire mesh, and netting should be installed at the water inlet and outlet as anti-escape and filtration facilities to strictly prevent harmful organisms from entering. 

Crayfish Rearing Techniques  

1. Field management. When raising crayfish in rice fields, aside from applying sufficient base fertilizer, feeding is not required. However, during the peak growth season of crayfish, some animal-based feed can be appropriately provided, such as crushed snails, mussels, and slaughterhouse by-products. Insist on patrolling the field every morning and evening to observe changes in water color in the ditch and the shrimp's activity, feeding, and growth conditions.  

2. Drying the field. When drying the rice field for rice harvesting, it should be lightly dried, and the field water must not be completely drained. It is sufficient to lower the water level until the field surface is exposed, and the time should be short. If abnormalities are found in the crayfish, water should be added immediately.  

3. Fertilizing the rice field. The base fertilizer for the rice field should be sufficient, mainly applying decomposed organic fertilizer, applied once into the plow layer before transplanting rice seedlings to achieve the goal of lasting and long-term fertility. Topdressing is generally done once a month, with 5 kg of urea per mu, 10 kg of compound fertilizer per mu, or organic fertilizer composted from human and livestock manure, which has no adverse effects on crayfish. Fertilizers harmful to crayfish, such as ammonia water and ammonium bicarbonate, are prohibited.  

4. Applying pesticides to rice. Crayfish are very sensitive to many pesticides. The principle of raising shrimp in rice fields is to resolutely avoid using pesticides when possible. When pesticides are needed, choose high-efficiency, low-toxicity pesticides and biological agents. When applying pesticides, strictly control the safe use concentration of the pesticide to ensure the safety of the shrimp. Spraying should be required on the rice leaf surface, try not to spray into the water, and it is best to apply pesticides in separate zones.  

5. Planting grass. Transplant aquatic plants in the surrounding ditch and field ditch, such as Vallisneria, Hydrilla verticillata, and Ceratophyllum demersum, which are submerged plants. The coverage of aquatic plants in the crayfish rearing ditch of the rice field should preferably be 10%-20%, and preferably sparse and dispersed.  

6. Preventing escape and disease. When patrolling the field every day, check whether the screen mesh at the inlet and outlet is firm and whether the anti-escape facilities are damaged. During the flood season, prevent the field from being flooded and prevent shrimp escape accidents.  

7. Harvesting. When raising crayfish in rice fields, as long as shrimp seed is stocked sufficiently at one time, after 2 months of rearing, a portion of the crayfish will reach commercial specifications. Long-term harvesting and catching large ones while leaving small ones is an important measure to reduce costs and increase yields. Crayfish that reach commercial specifications are harvested and sold on the market, while those that do not reach specifications continue to be raised in the rice field, reducing the density of crayfish in the rice field and promoting the rapid growth of small-sized crayfish.

Everything is difficult at the beginning. Before farming crayfish, the construction of the crayfish farming pond is the foundation of success or failure, so it must not be done carelessly. Before building the farming pond, the choice of site is also particularly important. Next is the construction of the pond. Different shrimps require different living environments, so it is relatively important to build an environment most suitable for their growth.