High yield and high efficiency techniques for interculture of river crab and crayfish

Since the introduction of fishery science and technology into households in Jianyang Town, Jianhu County in 2006, the technology of crayfish culture in crab ponds has been vigorously promoted, and a large number of science and technology demonstration households have emerged. For example, Chen Lvsheng, a demonstration household in Xinyang Village, implemented crayfish culture in crab ponds in 2008, which accumulated 80 mu, with an average yield of more than 150g per mu, and the largest individual male reached more than 300g. The yield of crayfish 65kg per mu is about 40g, and the net profit per mu is 2596 yuan, which greatly improves the benefit of unit accumulation and achieves high yield and high efficiency. This paper briefly introduces the high yield and high efficiency technology of interculture of river crab and crayfish.

1. Pond condition

The pond requires convenient entry and drainage, with a water depth of 1 to 1.5 m, a slope ratio of 1:3, and an asbestos tile around the pond field. 6m high anti-escape wall. Every December, ten mu of pond water is disinfected with quicklime 100~150kg, and the silt at the bottom of the pond is removed after ten days in the sun. The removed silt is used to strengthen the embankment, which should be made high and wide. The inside of the large embankment should be made into a small embankment, and the width of the small embankment is about 50cm, which is lower than that of the big embankment, and the crayfish are holed for mating and giving birth. The pond is equipped with 1 set of aeration aerator.

two。 Plant aquatic plants and release snail lions

A certain amount of Elorella was planted in the pond where shrimp and crabs were cultured, and properly matched with other submerged plants, water peanuts were planted at the edge of the pond, and aquatic plants were planted and accumulated into the pond. Aquatic plants should be planted in strips, with row spacing of 3mm and plant spacing of 2m. If aquatic plants are planted too densely, it will cause anoxia in the pond at night, and it is easy to cause turbid water at high temperature, and aquatic plants will rot due to high temperature and light, resulting in deterioration of water quality and disease of shrimp and crabs. Snail lion is a high-quality animal bait for river crab and crayfish, 300kg per mu, local fishing is better, and it is best to put it on the same day to ensure the survival rate of snail lion.

3. Seedling stocking

In the middle of March, there are 500 buckle crabs per mu, which are physically strong, disease-free and injury-free, with a specification of 80,000 crabs per kg. In the previous sentence of April, 6kg of crayfish larvae with strong physique, neat specifications and 300 crayfish / kg per mu were stocked for the second time. In the following year, except for the release of crab seedlings, there is no need to release crayfish seedlings.

4. Feed feeding

River crab and crayfish both belong to the order Decapoda, and their habits and eating habits are similar, so they are mainly fed with river crab bait, which is fed at a fixed point every day, and the daily feeding amount is 5% of the total body weight of river crab and crayfish in the pond. Wheat, soybean meal and rapeseed meal are fed in the morning, and full pellet feed is fed in the afternoon, so that shrimp and crabs can have enough to eat. It is also called proper fat and water to facilitate the growth and shelling of shrimp and crabs. In the early stage of breeding, the full-price feed with about 40% self-content of eggs was fed, the full-price feed with 28% self-content of eggs was fed in the middle high temperature season, and C was fed with full-price feed with 40% self-content of eggs in late August to fatten the river crabs.

5. Water quality management

From March to April, the water level is mainly tested, and the water level is kept at 0~30cm, which is called increasing light in order to increase the water temperature, promote the growth of aquatic plants and accelerate the growth and shelling of crayfish. In May, as the temperature rises, the water level rises gradually, and the steam reaches the highest water level. 20kg per mu of quicklime was disinfected once every 15 days, and fresh water was changed according to the water quality in the pond. The fresh water was discharged first and then advanced, and the water was changed for 3 times every month. After the fall of the temperature in autumn, the water level gradually decreased, so that the crayfish can make holes in time to mate and breed, and increase the population of crayfish next year.

6. Daily management

6. 1 take anti-escape and anti-theft measures, patrol the pond every day, observe the feeding activities, growth and shelling of shrimp and crabs, and deal with the problems in time.

6. 2 keep proper aquatic plants in the pond for shrimp and crab to perch and hide when shelling, so as to prevent each other from killing each other.

6. 3 feed should be sufficient, shrimp and crab can grow fast, large size and high yield only when they are full and well eaten.

6. 4 in the prevention and treatment of diseases and pests, the use of harmful drugs such as chrysanthemum and trichlorfon is prohibited to prevent damage to crayfish. Avoid the peak shelling period when using anti-ciliate drugs.