Freshwater crab varieties
1, hairy crabs
Hairy crabs, scientifically known as Chinese mitten crab, in the north called the river crab, the Yangtze River Basin called the hairy crabs, China's north of the Liao Henan to the Pearl River river, rivers, lakes, streams have its figure. The Yangtze River system of hairy crabs due to the wide distribution, high yield, is the representative species of southern China culture, famous for Yangcheng Lake hairy crabs, hairy crabs produced in Yangcheng Lake, characterized by green back, white belly, golden claw, yellow hair, is a very famous freshwater crab varieties, known as the "king of crabs", and now a lot of places in our country to use the mixed cultivation of rice and crab species, forming a number of crab rice brand products. Formed a number of crab rice brand products.
2, green crab
Green crab is also called saw edge green crab, its green crab shell is very hard, and oval, looks a little flat feeling, and the chest is very strong, the claw is very hard, with hitchhiking, so some people call it according to hitchhiking. Green crabs like to live in the intertidal sandy beaches, mangrove forests and marshes, and they are widely distributed in China, mainly in the coastal areas of Zhejiang, Guangdong, Guangxi, Fujian, etc., of which there are especially many in Jiangsu, Zhejiang, etc. The most famous of them is the green crab, which is the most famous of all. The most famous of the green crabs is the Sanmen green crab, a specialty of Sanmen County, Zhejiang Province, which is a national geographical indication product of China.
3, stone crabs
Stone crabs, also known as gomer crabs, creek crabs, is a freshwater crabs, mainly inhabiting in the mountains and streams under the stone, or stream banks on both sides of the water grass, as well as sand, and some of the cave in the rivers, lakes, ditches and ditches along the shore of the cave, in addition to a small number of distributors in Xinjiang, Qinghai, Inner Mongolia and the Northeast, the distribution of the other provinces have been. There are many varieties of river crabs, the more famous ones include the Chinese bunch-bellied crab, hairy-footed river crab, serrated Chinese river crab, Hainan river crab, purple small river crab and sharp-limbed South China Sea river crab. The stone crabs have full-flavored crab meat, surging crab paste and superb flavor.
4, water crabs
The production of water crabs is actually a stage in the growth process of green crabs. Just moulted crab body is soft state, called "soft shell crab", then due to the soft shell crab lying on the bottom of the water, will absorb a lot of water, resulting in the crab body stretching out, after 3-4 days, the new shell will be completely hardened, this shell from soft to hard shell moulting process, resulting in an increase in water content in the body of the green crab, the body weight doubled, so the name of the water crab. Water crabs, water crabs grow in brackish waters, their juices already carry a hint of salty flavor, so the taste is very fresh.
5, hairy crabs
Hairy crabs, also known as river crabs, crabs, clear water hairy crabs, the scientific name of the Chinese mitten crab, Chinese crabs in the production of the largest freshwater crab. Hairy crab is favored by domestic and foreign consumers for its rich nutrition and delicious meat. Hairy crab has become the main aquaculture varieties, hairy crab aquaculture industry has been the pursuit of yield "big crab" to the quality and efficiency as the center of raising large crabs and raising "ecological crab" change.
6, rice paddy crab
Rice paddy crab is actually the river crab, hairy crab, now many regions have the river crab in the rice paddy farming, and thus named rice paddy crab. Paddy crabs are important to feed on water plants, humus, snails, mussels, worms, insects, small fish, shrimp and so on.
Expansion: Freshwater Crab Farming Technology
1, buckle crab cultivation
Mian crab in order to improve the survival rate of young crabs, to increase economic benefits, the first thing to do is to cultivate buckle crab. In order to achieve the commercial crab, most of the plastic greenhouse temporary culture technology. Choose a pond with good water quality and sufficient water source, the area should not be too large, the water depth is not more than 1.2 meters, the pool shape east-west is good, sunny.
(1) Release seedlings. 15-20 days before the release of crab seedlings, per mu with 75 kg of quicklime splash disinfection, to be drug disappeared, with 80 mesh filter into the water, cultivate the basic bait, transplanting water plants (must be strictly disinfected), and set up the necessary anti-escape facilities. Crab seedlings can be appropriately shallow when entering the pool. It is conducive to raising the water temperature and the growth of algae and water plants in the water.
(2) Feeding. Feeding bait 2 to 3 times a day, feeding soybean paste, fish, shrimp mince, etc., feeding into should be more cast in the surrounding shallow areas, cast bait calculated at 4% of body weight, and always pay attention to the weather, water sanctions, individual growth, the bait organisms, depending on the amount of bait. With the growth of young crabs should also increase floating weeds and other high-quality water plants.
(3) Water quality. In the daily management of water quality regulation, to master the water quality is fat and fresh, water change should be changed diligently and less change, do not cause drastic changes in water temperature and water level. After about 2 months of cultivation can reach the button crab.
2, adult crab culture
Adult crabs like clean water, transparency of the water environment, aquatic plants, bait-rich, the most suitable for the growth of river crabs, most of the use of ponds, lakes, river swings and paddy field culture.
(1) pond conditions
meatballs near the square crab water supply is sufficient, easy to enter and drain, good water quality and pollution-free, choose clay, sandy or sandy soil, good ventilation, conducive to the growth and reproduction of aquatic grasses and benthic insects, snails and mussels, aquatic earthworms, etc., the old ponds should be thoroughly desilted, the shallowest 10cm, the pond can be built several slightly above the water surface of the mound, that is, the island of crabs, island aquatic plants can be transplanted! The pond should not be too steep, the slope ratio is generally below 1:1.5, otherwise, the river crab is easy to dig holes, and is not conducive to the evening climb out of the water activities. Artificial burrows can also be constructed.
(2) Transplanting water plants
The level of natural production of river crabs mainly depends on the amount of water plants and benthic organisms (bait organisms) in the waters. It is an indispensable technical measure to plant water plants in the process of culture. In addition to the vitamin supplement for crab feeding, the public also often say "crab size, look at the water plants".
(3) anti-escape facilities
Anti-escape facilities are mostly made of plastic film, but there are also cement boards, depending on the situation.
(4) Pond disinfection
Three-warted pike crabs are usually disinfected with quicklime half a month before the release of seedlings, the dosage of 75 kilograms per mu. On the one hand, it can kill hostile organisms, on the other hand, it can improve the bottom of the pond, increase the content of calcium ions in the water, and promote the growth of moulting of river crabs. Na water should be fertilized in time, cultivate algae and basic bait, transparency is generally maintained at 40 ~ 50cm is appropriate, if you find tadpoles or frog eggs should be removed in a timely manner, so as not to compete for food, endangering young crabs.
(5) release seedlings
Seedling purchase, the Yangtze River water system production of crab seedlings is preferred, the requirements of neat specifications, complete footsteps, robust, active crawling, no injuries and no disease.
Putting out seedlings: pay attention to the temperature difference when putting out seedlings. Seedlings purchased from abroad should first be immersed in water for 2 to 3 minutes, removed into the set for 10 minutes, so repeat 2 to 3 times, to be gradually absorbed by young crabs and adapt to the water temperature and then put into the pool, you can improve the survival rate.
Today's sharing is these, I hope to help you.