Crayfish belongs 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, native to North America, is an important species of freshwater shrimp culture in the United States. 19 18 In Japan, crayfish were introduced from the United States as bait for bullfrogs, and they proliferated and spread in a large area in Japan. During World War II, crayfish was introduced into China from Japan on 1938.

In China, crayfish first proliferated in Nanjing and suburban counties of Jiangsu Province. With the expansion of natural population and the development of human breeding activities, crayfish 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, Sichuan and Guizhou. 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 certain destructive effects on crops, dikes 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, and the requirements for culture conditions are not high, and the culture technology 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 is omnivorous, mainly feeding on organic debris, aquatic plants and animal carcasses in water, without feeding special feed, which not only has low breeding cost, but also has fast growth, high yield and good benefits.

4, the crayfish fishing method is simple, can be out of water for a long time, 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 deeply welcomed by domestic and foreign markets, and the products are in short supply and have broad market prospects.

Iii. Crayfish culture status

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 20th century, the Soviet Union used lake water to release crayfish artificially, and the factory seedling raising experiment was successful in 1960. 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.

Crayfish culture began in China in the 1970s. In 1974, crayfish was introduced from Nanjing by Wuhan Hankou Farm in Hubei Province for trial culture. Due to market reasons, the artificial culture of crayfish in China has never 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.

Two years ago, 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 2005, large-scale culture of crayfish has been started in Jingmen City, Hubei Province. In 2005, crayfish were cultured in ponds, paddy fields, swamps and other water bodies in Jingmen City, covering an area of 30,000 mu. Only the towns of Guandang and Maoli in Shayang County carried out "continuous cropping of rice and shrimp" with an area of10.5 million mu. In 2006, the crayfish culture area in Jingmen City reached 50,000 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 30,000 mu, which developed very rapidly.

Iv. Current situation of crayfish processing and export

Crayfish meat is delicious and nutritious. Protein content in shrimp meat accounts for 18% of fresh weight, fat is 0.3%, and total amino acid accounts for 77% of protein. It is a healthy food with high protein and low fat, and has become a delicious food on the table of 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.

1 10,000 tons of crayfish were exported for the first time in China in 1988, with an export volume of about 50 tons. By 2005, the national crayfish export volume reached110,000 tons, an increase of 200 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 2005, the national crayfish output was nearly 200,000 tons, and the output in Hubei Province alone reached 50,000 tons, including 3,000 tons in Jingmen City. Hubei Province now has a certain scale of crayfish processing plants 19. In 2005, crayfish export earned more than 80 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 600 tons; The "Changhu Lake Water Products Processing Factory" in Hougang Town, Shayang County has an annual processing capacity of more than 1000 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