Crayfish culture technology in rice field conditions of crayfish culture

At present, crayfish are distributed in many parts of our country, and there are more people raising crayfish now. In addition to the most traditional farming methods, crayfish farming in rice fields is also very popular. However, before using rice fields to cultivate crayfish, we must master the skills, and we also need to prepare for breeding in advance.

Culture techniques of crayfish in paddy field

1. Field disinfection: the field should be disinfected 15 days before shrimp release. The field can be sprinkled with quicklime 750kg / ha and 1125kg / ha. After the toxicity disappears, water can be entered.

2. Fertilization and water cultivation: 7-10 days before shrimp release, 60-80 cm of water was injected into the field ditch, and 15 tons of farm manure / ha was applied at a time to cultivate bait organisms.

3. Aquatic plant cultivation: aquatic plants such as Elorella verticillata (winter or early spring after ditch cleaning), verticillum verticillata and bitter grass (March) are planted in shrimp ditches and field ditches to ensure that the coverage rate of aquatic plants in the pond is more than 40%. 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.

4. Shrimp seedling delivery: it is appropriate to raise shrimp in rice field after transplanting seedlings in June, when the rice field has been cultivated, which is beneficial for freshwater lobster to adapt to the environment, can avoid damage to seedlings and improve the survival rate of shrimp. The general stocking standard is 250 million pieces / kg, and the stocking density of juvenile shrimp is 225000 ~ 300000 pieces / ha. Before stocking, it is necessary to wash and disinfect prawn seedlings and shrimp seeds with 3% salt water for 3-5 minutes.

5. Water and fertilizer management: after lobster stocking, field and ditch management is a very important link. The water depth of the paddy field is maintained at about 20 cm, and the water injection is usually carried out at 10: 00 to 11: 00, keeping the water temperature of the diversion water close to that of the paddy field. In the process of rice field management, the water level should also be regulated according to the requirements of rice drying and pest control. In the middle stage of rice growth, the field should be exposed properly, so as to increase light, root activity, sterilization and temperature. At ordinary times, we should also do a good job in flood control, drainage and escape prevention, and timely check whether the inlet and drainage and shrimp interception equipment are in good condition after a rainstorm to prevent shrimp escape.

Crayfish culture conditions

1. Create a good environment for lobster growth. Lobster is an insect shell animal, has a pair of specially developed claws, has the habit of digging holes and living in caves, generally digging holes near the waterside. Lobsters like shade and fear light, climb out of the cave when the light is weak or dark, and sink to the bottom or hide in the cave when the light is strong. According to the habits of the lobster, an anti-escape net of 50 cm high can be set up by the river pond to prevent the lobster from escaping. At the same time, the river pond simulates the ecological environment of lobster under natural conditions, planting 10-15% of aquatic plants and concealment on the edge of the pond, creating an environment for lobster habitat and shelling, and reducing the killing of each other.

2. The effect of water quality on lobster yield can not be ignored. The water quality has a direct impact on the healthy growth and development of lobster. In the process of culture, the ph value of the pond water is kept between 7.5-8.5 and the transparency is 30-40 cm. New water should be injected frequently and quicklime solution should be sprinkled regularly to regulate the water quality to prevent diseases and failed shelling.

Feeding and management of crayfish

Shrimp culture in rice fields should try to achieve timing, positioning, quantitative, qualitative feeding. Lobster eating habits are miscellaneous, meat (small fish, snail meat, river meat, fish, earthworms, animal offal, silkworm pupa), essence (sugar cakes, corn, wheat, barley flour), green (there are all kinds of aquatic grasses, vegetable scraps, etc.) feed. The daily dosage is generally 40.6% of the body weight of shrimp. In the early stage, they were fed twice a day, once in the morning, once in the afternoon, and once at about 18:00 in the later stage.

What about the ciliosis of crayfish?

Ciliosis is caused by the attachment of ciliates, which is characterized by the formation of a thick layer of "hair" on the body surface, appendages and gills of adult shrimp, juvenile shrimp, larvae and fertilized eggs.

Prevention and control methods:

1. 0.3~0.5mg/L tetraalkyl quaternary ammonium salt was used to complex iodine and sprinkle it all over the field.

2. Use fipronil or zinc sulfate as instructed. In addition, feeding special artificial feed for molting of Procambarus clarkii can promote the molting of Procambarus clarkii and make it get rid of the old shell with ciliates.

Crayfish culture in rice fields should first do a good job of site selection, then disinfect them, and then put in shrimp seedlings. Feeding needs to be strengthened in the later stage of culture, and timely disease control is also a key factor to ensure its growth. Only by doing this well can the crayfish grow well.