Main preparations for artificial culture of crayfish in ponds

In September and October, the sale of artificially farmed crayfish is basically over, and everyone begins to prepare for the next season of crayfish culture. many farmers do not have a clear understanding of the importance of the preparatory work before breeding, but simply deal with the pond, or even do not deal with it at all, so they directly put in the shrimp for the next season. The effect of such culture is often very unstable.

The main preparatory work for artificial culture of crayfish in the pond: first, clear the pond and disinfect: drain the pond water, catch and sell the mixed-cultured silver carp and other fish in the pond for a week; enter the water for about 30 centimeters, it is recommended to disinfect with 20 kg / mu of bleach to kill the enemy pests in the pond, such as wild miscellaneous fish and disease-causing microorganisms. Killing wild miscellaneous fish must be thorough, otherwise it will affect the effect of culture. Wild miscellaneous fish eat very quickly, not only with crayfish but also crayfish seedlings. Once there are many wild miscellaneous fish in the pond, the emergence rate and survival rate of crayfish are very low, which has a great impact on the yield of crayfish. In this way, the crayfish does not grow well, the size of the crayfish is small, and the yield is low. Second, recommended: bleach disinfection for a week, the toxicity basically disappeared, then you can plant aquatic plants. A good pond of grass is the key to the success of crayfish culture. According to the experience, it is suggested that the mixed species of Elorella, water peanut and bitter grass are recommended, and the effect is better. Third, water intake and fertilizer water: after planting water plants, you can enter the water, the water depth should be more than 50 centimeters, and the water inlet should be covered with a dense net of 80 mesh to prevent wild fish and fish eggs from entering the pond. When the water reaches the right water level, when fermented organic manure is used, we generally use fermented chicken manure, which is about 100 jin per mu, plus 20 jin of quicklime (quicklime and fermented chicken manure are mixed for a week). In the application of fermented chicken manure combined with Bacillus and other biological agents, the fertilizer and water effect will be better and the effect will be more lasting.

Culture technique of crayfish in rice field

I. Paddy field selection

Paddy fields should choose loam with adequate water source, good water quality, quiet surrounding environment, convenient drainage and irrigation, and convenient transportation, and the water source should be large-scale water body without pollution; the field should not be affected by drought and flood, and the water quality is fresh and pollution-free, the soil is fertile but not silted, the ridge is high (the water depth that can be infused with 40~60cm) and solid, and it does not leak, the water retention performance is good, and the sun is sufficient.

II. Field engineering construction

Field construction mainly includes ridge widening, heightening and reinforcement. The inlet and outlet is equipped with filtration and escape prevention facilities, excavation of annular ditches and field ditches, installation of shading canopy, etc. A circular ditch is dug around the rice field as a shrimp culture ditch to ensure that the annular ditch is 3cm wide and 1.0m deep and the field area is larger, and the "field" or "well" shaped field ditch should be dug in the middle. The width and depth of the field ditch are 1.0 m and 0.5 m respectively. The area of circular shrimp culture ditch and field ditch accounts for about 10% of the rice field area.

Third, disinfect and cultivate water

1. Disinfection

The field should be disinfected 15 days before shrimp release, and 750~1125kg/hm2 can be sprinkled with quicklime. After the toxicity disappears, the water can be entered.

2. Fertilize and cultivate water

Seven to ten days before shrimp release, water 60~80cm was injected into the field ditch, and farm manure 15~30t/hm2 was applied at one time to cultivate food organisms.

3. Aquatic plant planting

Aquatic plants such as Elorella verticillata (winter or early spring after ditch cleaning), verticillium verticillata and Sophora flavescens (March) were planted in shrimp ditches and field ditches to ensure that the coverage rate of ditch water plants in the pond reached more than 40%, so as to meet the environment for the growth and development of lobsters. In order to provide bait for shrimp species, some snails can be put in to allow them to reproduce naturally.

The living habits of crayfish

Crayfish have a wide range of adaptability and a wide range of suitable growth temperature, and can grow and develop normally when the water temperature is 10-30 ℃. It can also withstand high temperature and severe cold, can withstand a high temperature of more than 40 ℃, and can survive the winter safely when the temperature is below-14 ℃. Crayfish grows rapidly. Under the condition of suitable temperature and sufficient food supply, after more than 2 months of culture, it can achieve sexual maturity and meet the specifications of commercial shrimps. Generally, the growth of male shrimp is faster than that of female shrimp, and the size of commercial shrimp is also larger than that of female shrimp.

Like many crustaceans, the growth of crayfish is accompanied by molting, generally looking for shelter, such as in aquatic bushes or under plant leaves. The maximum weight gain after molting can reach 95%. Generally, sexual maturity can be achieved after 11 molts, and sexually mature individuals can continue to molt and grow. Its life span is not long, about 1 year. However, in the case of lack of food, low temperature and relatively dry conditions, the life span can be up to 2-3 years.

I like to dig holes in the breeding season. The cave is located about 20 cm above the water surface of the pond, with a depth of 60 cm to 1.2 m. There is a small amount of stagnant water in it to maintain humidity. The mouth of the cave is generally sealed with a mud cap to reduce water loss. On summer nights or after heavy rains, it has the habit of climbing ashore and can cross dams and enter other bodies of water.

Crayfish culture cycle

Depending on the water temperature, the breeding period of lobster is somewhat different from that of ordinary animals. generally, the breeding period of lobster is mostly in spring, while the breeding period of lobster is mostly in autumn, and the seedlings can only grow from winter to summer, because the water temperature is low in winter. Seedlings grow slowly, even not long. If the water temperature is right, nutritious lobster can grow in only 50-70 days.

It also depends on the situation. if the wild ones reproduce very fast, release the shrimp in March-April and directly let the prawns reproduce freely. They can be caught around June, and can be caught every day in the future.

With the continuous development of the midnight snack industry, many midnight snack shops continue to open, and there are many professional lobster shops, so the market prospect of crayfish is very good, and its demand is increasing, so its development prospect is very good.