crayfish belong to Arthropoda, Crustacea and Procambarus in animal taxonomy. Also known as crayfish, Procambarus clarkii or freshwater crayfish, it belongs to small and medium-sized freshwater crayfish species.
Crayfish is native to North America and is an important species of freshwater shrimp culture in the United States. In 1918, Japan introduced crayfish as bait for bullfrogs from the United States, and it proliferated and spread in a large area in Japan. In 1938, during World War II, crayfish were introduced to China from Japan.
In China, crayfish first propagated in Nanjing and suburban counties of Jiangsu Province. With the expansion of natural population and the development of human breeding activities, they are now widely distributed in Xinjiang, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan, Hebei, Tianjin, Beijing, Liaoning, Shandong, Jiangsu, Shanghai, Anhui, Zhejiang, Jiangxi, Hunan, Hubei, Chongqing and Jiangxi. In the middle and lower reaches of the Yangtze River, the biological population is relatively large.
second, the advantages of crayfish varieties
crayfish has strong adaptability, rapid reproduction and migration, and likes to dig holes, which has a certain destructive effect on crops, embankments and farmland water conservancy facilities. In China, it has been regarded as an enemy for a long time, and many people are still worried. However, the digging ability, climbing ability and moving speed on land of crayfish are far weaker than those of Eriocheir sinensis. Generally speaking, crayfish, as an aquatic resource, has many advantages and fewer disadvantages for human beings, and has high development value. As a cultured variety, crayfish has the following advantages:
1. Crayfish has strong adaptability to the environment, few diseases, can grow in lakes, ponds, river ditches, rice fields and other water bodies, has low requirements for breeding conditions and is easy to popularize.
2. Crayfish can directly convert plants into animal proteins, and its growth rate is fast. Generally, it can reach the market specifications after 3-4 months of cultivation, so it has a high energy conversion rate.
3. Crayfish are omnivorous, mainly feeding on organic debris, aquatic plants and animal carcasses in water, and do not need to be fed with special feed, which is not only low in breeding cost, but also fast in growth, high in yield and good in benefit.
4. The crayfish fishing method is simple, it can stay out of water for a long time, and it is convenient to transport and has a high survival rate. It is time-saving and labor-saving in fishing and product transportation, and the cost is low, which is incomparable to cultured fish.
5. Crayfish is delicious and nutritious. It is a common dish of urban and rural people in China, and it is also the main export variety of freshwater aquatic products in China. It is well received by domestic and foreign markets, and the products are in short supply and have broad market prospects.
III. Crayfish breeding situation
Crayfish has the characteristics of miscellaneous eating habits, strong reproduction, wide adaptability, fast growth, strong disease resistance and high survival rate, so crayfish breeding and processing have a history of one hundred years.
at the beginning of the 2th century, the Soviet Union used lake water to release crayfish artificially, and in 196, the factory seedling experiment was successful. The United States is the most effective country for crayfish culture, and Louisiana, the United States, is famous for its crayfish culture in the world. The main culture mode adopted is "growing rice and raising shrimp". That is, rice is planted in rice fields, and when the rice is ripe, it is flooded with water, and then crayfish seedlings are released. The flooded rice is directly or indirectly used as food for crayfish growth.
China began to breed crayfish in the 197s. In 1974, Hubei Province introduced crayfish from Nanjing by Wuhan Hankou Farm. Due to market reasons, the artificial culture of crayfish in China has not formed a climate. In recent years, many provinces, municipalities and autonomous regions have introduced crayfish from Hubei and Jiangsu for trial culture, but most of them are artificially released. At present, a few provinces (cities) such as Hubei, Jiangsu, Anhui, Beijing, etc. have formed a craze for artificially breeding crayfish.
in the first two years, Qianjiang city, Hubei province, under the guidance of the provincial fisheries research institute, carried out the trial cultivation of "continuous cropping of rice and shrimp" and achieved good economic benefits. Since 25, large-scale culture of crayfish has been started in Jingmen City, Hubei Province. In 25, crayfish were cultivated in ponds, paddy fields, swamps and other water bodies in Jingmen City, covering an area of 3, mu, and the area of "continuous cropping of rice and shrimp" in Guandang, Maoli and other towns in Shayang County alone reached 15, mu. In 26, the crayfish culture area in Jingmen City reached 5, mu, and the shrimp culture area of three modes, namely "continuous cropping of rice and shrimp", "rice and shrimp rotation" and "raw rice and shrimp", reached 3, mu, which developed very rapidly.
iv. current situation of crayfish processing and export
crayfish is delicious and nutritious. Shrimp meat contains 18% protein, .3% fat and 77% amino acids in protein. It is a healthy food with high protein and low fat, and has become a delicacy for urban and rural residents in China. In addition, shrimp shells are rich in nutrients such as calcium, phosphorus and iron, which can be processed into feed additives and industrial raw materials such as chitin, chitin and chitosan, and are widely used in agriculture, food, medicine, tobacco, paper making, printing and dyeing. In addition, crayfish have been exported to Europe and America in recent years, which has become the main product of freshwater aquatic products exported to Europe and America. Because crayfish is well received by domestic and foreign markets, the market demand exceeds supply, and the price keeps rising, which exceeds the market price of traditional fish. Therefore, the crayfish industry has high economic benefits and broad development prospects, and it is a good channel for farmers to get rich.
in p>1988, China exported crayfish for the first time, with an export volume of about 5 tons. By 25, the national crayfish export volume reached 1, tons, an increase of 2 times. At present, the export of crayfish in Hubei Province has surpassed that of Jiangsu Province to become the highest in the country, and the processed products are mainly exported to the United States and Europe. In 25, the national crayfish output was nearly 2, tons, and the output in Hubei Province alone reached 5, tons, including 3, tons in Jingmen City. There are 19 crayfish processing plants in Hubei province, and the export of crayfish in 25 earned more than 8 million US dollars.
There are two large-scale crayfish processing plants in Jingmen City, namely "Churunzi Dew Products Processing Plant" in Song He Town, jingshan county, with an annual processing capacity of over 6 tons; The "Changhu Lake Water Products Processing Factory" in Hougang Town, Shayang County has an annual processing capacity of more than 1, tons. There are five crayfish processing factories under construction and expansion in the city. It is expected that by the end of the Eleventh Five-Year Plan period, the whole city will