What are the main preparatory steps for artificial crayfish farming in ponds?

Entering September and October, sales of artificially farmed crayfish are basically over, and everyone begins preparing for the next season of crayfish farming. Many farmers do not clearly understand the importance of pre-farming preparation work, and only give the pond a simple treatment, or even no treatment at all, and directly stock broodstock for the next season of farming. The results of such farming are often very unstable.

Main preparatory work for artificial crayfish farming in ponds1. Pond clearing and disinfection: Drain the pond water, catch and sell all the silver carp and bighead carp and other fish that were polycultured in the pond, and dry the pond for one week; add water to about 30 cm, and it is recommended to use 20 kg of bleaching powder per mu for disinfection to kill harmful organisms in the pond such as wild trash fish and pathogenic microorganisms. Wild trash fish and the like must be killed thoroughly, otherwise the farming results will be affected. Wild trash fish eat very quickly, not only competing with crayfish for food but also eating crayfish fry. Once there are many wild trash fish in the pond, the fry emergence rate and seedling survival rate of crayfish are both very low, which has a great impact on crayfish yield. In this way, crayfish grow poorly, crayfish size is small, and yield is low.2. Planting grass: One week after disinfection with bleaching powder, the toxicity has basically disappeared, and at this time aquatic plants can be planted. A pond of good grass is the key to successful crayfish farming. Based on experience, it is recommended to plant a mixture of three grasses: Elodea, Alternanthera philoxeroides and Vallisneria, and the effect is relatively good.3. Adding water and fertilizing the water: After the aquatic plants are planted, water can be added, and the water depth should be above 50 cm. The water inlet should be covered with an 80-mesh fine net to prevent wild trash fish and fish eggs from entering the pond. When the water reaches a suitable level, apply well-fermented organic manure. We generally use fermented chicken manure, with an application rate of about 100 jin per mu, plus 20 jin of quicklime (quicklime and fermented chicken manure are applied after being mixed for one week). When applying fermented chicken manure, combine it with biological agents such as Bacillus, and the water fertilization effect will be better and longer lasting.

Crayfish rice-field farming technology  

1. Rice-field selection  

For the rice field, it is best to choose loam with sufficient water sources, good water quality, a quiet surrounding environment, convenient irrigation and drainage, and convenient transportation. The water source should be selected from large water bodies without pollution; the field should not be affected by drought or flood disasters, the water quality should be fresh and pollution-free, the soil should be fertile but not silty, and the field ridge should be high (able to hold a water depth of 40-60 cm) and solid, without water leakage, with good water retention performance and sufficient sunlight.  

2. Field engineering construction  

Field construction mainly includes widening, raising and reinforcing the field ridge. Filtering and escape-prevention facilities are installed at the water inlet and outlet, ring ditches and field ditches are excavated, and shade sheds are installed, etc. Dig ring ditches around the rice field as shrimp-culturing ditches, ensuring that the ring ditch is 3-5 m wide and 1.0 m deep. For larger fields, a "field"-shaped or "well"-shaped field ditch should also be dug in the middle, with the field ditch width and depth being 1.0 m and 0.5 m respectively. The area of the ring shrimp-culturing ditch and field ditches accounts for about 10% of the rice-field area.  

3. Disinfection and water fertilization  

1. Disinfection  

15 d before releasing shrimp, the field should be disinfected. Quicklime can be splashed at 750-1125 kg/hm2. After the toxicity disappears, water can be added.  

2. Fertilization and water cultivation  

7-10 d before releasing shrimp, inject water 60-80 cm deep into the field ditches, and apply 15-30 t/hm2 of farmyard manure at one time to cultivate food organisms.  

3. Aquatic plant planting  

Plant aquatic plants such as Elodea (in winter or early spring after clearing the ditch), Hydrilla verticillata and Vallisneria (in March) in the shrimp-culturing ditches and field ditches, so as to ensure that the aquatic plant coverage rate in the pond ditches reaches more than 40%, meeting the environment needed for crayfish growth and development. In order to provide feed for the shrimp seed, some river snails can be put in and allowed to reproduce naturally.

Living habits of crayfish  

Crayfish are extremely adaptable and have a relatively wide suitable growth temperature range. They can grow and develop normally when the water temperature is 10-30°C. They can also tolerate high temperatures and severe cold, can withstand high temperatures above 40°C, and can also overwinter safely when the air temperature is below -14°C. Red swamp crayfish grow rapidly. Under suitable temperatures and sufficient feed supply, after more than 2 months of farming, they can reach sexual maturity and reach commercial shrimp size. Generally, male shrimp grow faster than female shrimp, and commercial shrimp size is also larger than that of female shrimp.  

Like many crustaceans, the growth of red swamp crayfish is also accompanied by molting. When molting, they generally seek hiding places, such as among aquatic grass or under plant leaves. After molting, the maximum body weight increase can reach 95%. Generally, after 11 molts they can reach sexual maturity, and sexually mature individuals can continue to molt and grow. Their lifespan is not long, about 1 year. However, under conditions of food shortage, lower temperatures and relatively dry conditions, the lifespan can reach up to 2-3 years.  

In the breeding season, they like to dig burrows. The burrow is located about 20 cm above the pond water surface, with a depth of 60 cm to 1.2 m, and contains a small amount of accumulated water to maintain humidity. The burrow opening is generally sealed with a mud cap to reduce water loss. On summer nights or after heavy rain, it has the habit of climbing ashore, and can cross embankments and enter other water bodies.

Crayfish farming cycle  

The key depends on water temperature. The breeding period of crayfish is somewhat different from that of ordinary animals. Ordinary animals mostly breed in spring, while crayfish mostly breed in autumn. The seedlings must go through a winter to summer before they can grow to maturity, because in winter the water temperature is low, and the seedlings grow slowly or even do not grow. If the water temperature is suitable and nutrition is rich, crayfish can grow to maturity in only 50-70 days.  

It also depends on the situation. If wild, because they reproduce very quickly, release shrimp in March-April, directly release large shrimp and let them reproduce freely, and they can be caught around June, and after that they can be caught every day.

With the continuous development of the late-night snack industry, many late-night snack shops are constantly opening, and there are also many specialized crayfish restaurants. Therefore, the market prospects for crayfish are very good, and demand is also growing. Therefore, its development prospects are very good.