The origin of crayfish, the history of crayfish?

Crayfish were originally used as feed for bullfrogs and were later introduced to China.

In 1927, the first crayfish was introduced in Japan for the purpose of being used as feed for bullfrogs. It was introduced to China about two years later, and the earliest breeding grounds were near Nanjing.

Lobsters are shaped like shrimp with a hard shell. The adult is about centimeters long and has a reddish-brown, reddish-brown and pink color. The back is dark red and pink on both sides, with orange or white spots.

Part of the carapace is almost black, with wedge-shaped stripes on the back of the abdomen. The larvae are gray and sometimes have black ripples. Narrow pliers. The middle part of the carapace is not separated by mesh gaps, and there are obvious particles on the carapace.

Extend your data. Crayfish can adapt to various polluted environments, thanks to its good detoxification and detoxification mechanism, so the amount of pollutants in its body may not exceed the standard. Crayfish can transfer heavy metals inside the shell and then transfer the toxins out of the body through constant molting, which is one of the reasons why it is able to tolerate heavy metal contamination.

Current studies have shown that heavy metals are mostly concentrated in the gills, internal organs and shells of shrimp that we don't like to eat. For people who eat shrimp meat, it is less likely to cause heavy metal poisoning.

Crayfish are farmed all over the world and form huge wild populations. China was introduced from Japan in the 30s and 40s of the 20th century, and Japan introduced it from the United States in an earlier period, mainly for food and pets.

Crayfish are often polycultured in fields of crops such as rice. There is no need for artificial incubation, and once the pond is stocked with seeds, it is self-sustaining, and after harvesting, there is no need to restock. Escaped specimens survive by digging holes in the levees.

They can survive in temporary water bodies and have a wide range of feeders, establishing populations very quickly and spreading easily.

It is extremely threatening to local fish, crustaceans and aquatic plants, and disrupts the local food chain; Direct catastrophic damage to crops (especially aquatic and semi-aquatic crops such as rice) and natural vegetation due to its feeding on the root system; Hole construction causes the loss of irrigation water and the destruction of fields; Due to the mixed feeding habits of crayfish, it has a certain degree of influence on the development of fish fry and the cultivation of 1st instar fish fingerlings, and harms artificially bred juvenile mussels.

Due to its strong adaptability, strong resistance to stress, wide diet, and rapid population proliferation, crayfish often cut crops, especially rice crops, and may compete with local freshwater crayfish species.

Habitat

Inhabit permanent streams and swamps, temporary habitats, including ditches and ponds. In streams, they are often mixed with plant or woody detritus, which can damage and weaken the embankment. In areas where the flood waters have receded, it can be found in simple caves.

Lives in wetlands, lakes and ditches with shallow water bodies and abundant aquatic weeds.

The species is found in a wide range of habitat types, including wetland meadows, subterranean karst systems, seasonal marshes and marshes, permanent lakes and streams, rice paddies, irrigation channels, and reservoirs. This species is able to tolerate a range of environmental conditions, including low oxygen levels and high temperatures.

Crayfish were originally fed by bullfrogs and later introduced to China.

In 1927, the first crayfish were introduced in Japan for use as feed for bullfrogs. About two years later, it was introduced to China, and the earliest breeding grounds were near Nanjing.

In China, crayfish (crayfish) were transplanted from Japan to the Nanjing area in 1929 [9]. Later, through artificial breeding and promotion, it gradually expanded to Beijing, Tianjin, Hebei, Shanxi, Henan and other provinces and cities. It can survive and develop in the south and north of China, and has become a population naturalized in China's natural water bodies.

In the early 1990s, the crayfish industry in Xuyi County, Jiangsu Province began to develop.

In 2000, Xuyi County held the "Lobster Festival", after which Xuyi lobster began to expand to Jiangsu, Zhejiang, Shanghai and the whole country. Xuyi's "Thirteen Spice Spicy Crayfish" is famous in China, and "Thirteen Spice Spice" is a conventional name, which is actually made up of more than 20 spices that can be used together to create a variety of flavors.

Since the 2000s, the spicy crayfish ("Ma Xiaoer") from Gui Street in Beijing has gradually become a famous snack in Beijing, a common meal, widely welcomed by diners, and some are made into lobster sauce for export.

Today, although crayfish is still listed as an invasive species in China, the number of wild crayfish can no longer meet the huge consumption, and crayfish farming has become an important industry in many places. Hubei, Anhui, Jiangsu, Hunan and other major producing areas of the local ** and related organizations also participate in industrial planning to promote industrial development.

Native to the Gulf Coast of the United States from northern Mexico to the narrow Strip of Florida and the interior of the United States in Illinois and Ohio, it has since been introduced to Asia, Africa, Europe and other parts of the Americas, making it an extremely widespread invasive alien species. In southern Europe, the crayfish reproduces rapidly, crowding out the space for the local European crayfish and giant crayfish.

Ecology mainly lives in warm freshwater waters, such as slow-flowing rivers, swamps, lakes and rice paddies. It grows fast and can tolerate up to 4 months in the dry season without water. The maximum weight can exceed 50 grams, and the body length varies from centimeters to 12 centimeters.

This species also tolerates slightly saline water, which is rare in freshwater crayfish. During the wet season, this species can find habitat across miles of dry land. In general, it is possible to live for five years, although some individuals are known to survive for more than six years in nature.

Crayfish were introduced to Japan during World War II, but it is not very clear whether they were used to dispose of corpses. The scientific name of crayfish is crayfish, which can also be called red crayfish or freshwater crayfish. Crayfish belong to the large family of arthropods and belong to the crustaceans along with lobsters, crayfish, crabs, river prawns, and prawns.

Professor Cai Shengli of the School of Fisheries of Shanghai Fisheries University introduced that crayfish is an authentic "imported product". Crayfish are native to North America and are an important species for freshwater shrimp farming in the United States. In 1918, Japan introduced crayfish from the United States as bait for bullfrogs, and crayfish were reproduced and spread in a large area in Japan.

During World War II, crayfish was introduced into China from Japan, began to breed in Nanjing City, Jiangsu Province and suburban counties, after a long time of expansion, the population continues to increase, the living space continues to expand, and now, it has become an important resource in China's freshwater shrimp, widely distributed in the provinces and cities in the middle and lower reaches of the Yangtze River in China. Crayfish are good at "going with the flow", rivers, lakes, reservoirs, rice fields, and ponds can all become a safe place for crayfish. When the water temperature rises in spring, the crayfish often move in shallow water, and in the middle of summer, when the temperature rises, it lurks in deep water, and in winter and when it sheds its shells and breeds, the crayfish spends its time in burrows to prevent other animals from attacking.

Crayfish not only have strong feeding ability, but also have the habit of gluttony and competition for food. In the case of high reproductive density or starvation, cannibalism can occur between crayfish, and freshly shelled crayfish and juvenile shrimp often become a "meal" for "strong" lobsters. Crayfish have very strong feeding ability and reproductive ability, and have low requirements for the growing environment.

Crayfish is an omnivore and mainly eats animals, small fish, shrimp, plankton, benthic organisms, algae, etc. can be used as its food. From June to August every year, it is the time when the crayfish is the most "plump", and the crayfish shell at this time is hard and thick, and it is also the best time for people to catch and enjoy it.

The origin and historical events of crayfish:

The origin of crayfish dates back to World War II.

The Japanese biochemical troops stationed in China had to dispose of a large number of corpses, but considering that the energy consumption of a crematorium was too high, if the primary cremation was carried out and then decomposed into small pieces for discharge, it would cause serious eutrophication of the surrounding water bodies.

and even led to the plague.

Spread, so the Japanese thought of the crayfish that could be seen everywhere in Japan at that time, and after a series of genetic modifications, the crayfish were transported in batches to the Japanese military garrison to clean the water.

The improved crayfish showed better ability to adapt to high spoilage water bodies than its predecessors, stronger reproductive ability, especially the ability to adapt to mineral poisoning water bodies, and the Japanese side declassified archives showed that high nutrition, paragonimiasis and black gill disease in low-oxygen water bodies, crayfish crayfish were almost lifelong carrying, but mortality.

Close to normal.

and lead, mercury, arsenic and other serious teratogenic chemical elements.

Even if the accumulation was hundreds of times the normal value in the crayfish, no large-scale gene mutations were observed in the offspring.

Since then, the crayfish has survived in Chinese mainland by frantically eating the uncremated corpses of the Chinese, and with the surrender and retreat of the Japanese army, the crayfish has been left from the mainland of China.

In the early days of China's establishment, crayfish used to breed wildly. At that time, people felt that crayfish was a scavenging organism, and the water quality of life was very poor, and they were not willing to try to eat it even if they were miserable.

With the beginning of the three-year natural disaster, tree bark, grass roots, Guanyin soil, etc. are all food that people compete for, and for a while, people are searching for everything they can eat in order to survive. Crayfish are no exception! The initial approach was relatively simple, as resources were scarce at the time.

Mostly boiled and steamed.

Later, people's material civilization became more and more abundant. It's not just about being full, it's about the taste of the food. The crayfish continued to start the journey at the table.

With spicy crayfish.

Crayfish with garlic and braised prawns in oil.

Crayfish has become an indispensable dish on the wine table. The status of crayfish also began to rise, and crayfish in the wild were once eaten to extinction. Therefore, farming crayfish has become a way for many people to make a fortune.