Method for breed crabs in Daqing

Crab seedlings produced in the Yangtze River system are the best seed selection, requiring neat specifications, complete steps, strong physique, active crawling and no injuries.

Sowing and density, pay attention to temperature difference when sowing. Fish fry bought from other places can't be directly put into the pond. They should be soaked in water for 2 ~ 3 minutes, taken out and put into the pond 10 minute, and so on for 2 ~ 3 times. Young crabs gradually absorb enough water, adapt to the water temperature, and then put them into the pond, which can improve the survival rate.

Density: most of them are polyculture, especially fish, shrimp and crab polyculture, and the economic benefit will be higher. The density can be controlled within 1500 crabs/mu, and the specification is 120 ~ 150 crabs/kg. If the conditions are poor or shrimp farming is the main thing, the amount of seedlings released can be reduced appropriately.

2. Daily management

(1) The whole process of intensive culture in ponds mainly depends on artificial feeding, and other plant feeds account for 25%. There are three main types of feeds.

(1) Full-price special compound feed for river crabs;

(2) Animals: small miscellaneous fish in sea and fresh water, corpses of various animals, snails, mussels, blood of livestock and poultry, fish meal, silkworm chrysalis, etc. ;

(3) Botany: aquatic plants, duckweed, Alternanthera philoxeroides, Sophora alopecuroides, black algae, etc. And commercial feed: sweet potato, potato, cereal, bran, feed bran, etc. Like pond culture, the feeding method of river crabs is "four observations and four determinations", that is, observing seasons, weather, water quality and crab activities regularly, regularly, qualitatively and quantitatively.

(2) Look at the season:

In spring, young crabs should be fed some live animal feed. In the middle growth period of river crabs, especially in May and August, it is necessary to appropriately increase the amount of animal feed to make the river crabs gain weight and have delicious meat. Feed distribution is generally 40% from March to June, 7- 10 is 60%, and the water temperature is below 10℃.

(3) Look at the weather: feed more on sunny days and feed less on rainy days. In hot and humid weather, you can stop feeding before there are no winds and showers, and in foggy days, wait until the fog is closed before feeding.

(4) Look at the water quality: the water quality is clear, the bait can be fed normally, and the water quality is strong. Reduce feeding appropriately and change water in time.

(5) Look at the activity of crabs: they are generally eaten up the next morning after feeding, and the amount of bait is appropriate, indicating that the appetite of river crabs is not strong or excessive. It is necessary to analyze the reasons in time, reduce the feeding amount, and appropriately increase the feeding amount of crabs when molting.

(6) Timing: Eriocheir sinensis has the habit of staying up at night. Go out for food at night, feed at eight or nine in the morning and feed at night. The feeding amount at night is 60 ~ 70% of the whole day.

(7) Fixed point: The feed to be fed should have fixed food, and the feed should be scattered on the feed table or on the slope near the shallow water level, so as to observe the feeding and activities of the river crab and increase or decrease the feed at any time. Chinese mitten-handed crabs have a strong competition for food, so it is necessary to set up more points so that Chinese mitten-handed crabs can eat evenly and avoid killing each other because some of them are small or weak and can't compete for feed.

(8) Qualitative judgment: Eriocheir sinensis is sensitive to fragrant, sweet, bitter, salty and smelly tastes, and its feed must be fresh and palatable, and rich in protein.

(9) Quantification: "If you don't eat fish for one day, it will last for three days", and the same is true for river crabs. This requires that the feeding amount should be determined according to the size, density, different seasons, weather and activities of river crabs. Generally, the daily feeding amount is 8- 10% of the body weight of the pond crab. If the feeding amount is small, it can only maintain life, and if it exceeds the timely range, it will also affect growth and increase feed coefficient.