Xinhuanet Anhui Channel
At present, the word "Hou-"has become popular in the cultural circle. What are the "post-love era" and "post-SARS era"? Even Jingtong Expressway and its dozens of expressways are euphemistically called "the back garden of CBD", so that some people say that there is no fashion in our time, and the so-called fashion is only a few slaves who are willing to be business followers in developed countries. Let's talk about this "post-SARS era" first. There is a fashion that is not a follower, at least it is "sloppy".
Elephants are brilliantly rendered as culture. A naturally curious person like me should be very happy to see something that makes his mouth happy. Life is so dull, if the taste buds are underdeveloped, it is better to find a tree hole to sleep like a bear and endure it quietly until it is awakened by the noise outside.
The first time I ate "Ma Xiao" in my life was in the food stall of Beijing Gulou. At that time, Gui Street in Dongzhimen was unknown (note: the most famous crayfish in China was not Gui Street, but Xuyi in the south of the Yangtze River, where the first China Lobster Festival was held in 2000). Crayfish are not fried with excessive chilies and red peppers, but are cooked with stewed sheep scorpion soup, and some are just cooked. With the repeated encouragement of my friends, I ate seven or eight. To be fair, the taste is ok, but it feels dirty when it is peeled off. If I pick out the meat and rinse it, it will look a little ugly. I am more suspicious of its life experience and my health.
In fact, there are many discussions about crayfish, and the basic feedback from the city intelligence station is to praise more and scold less. I have been observing why, but I have long recognized that there must be some commercial factors behind these efforts, which are the main interests of some groups or individuals.
A crayfish, what does this cheap crayfish have to do with those expensive lobsters? What kind of past life did it have? You may not believe it, but that cute little thing is devouring your precarious health. Allow me to tell you the truth-
Crayfish is another name for crayfish, also known as crayfish or crayfish. Written in English as "crawdad", the official scientific name is "Procambius clarkii". It belongs to crustacean river shrimp, which is as small as lobster, so it is also called crayfish. The first step is very developed. The shell is bright and beautiful, showing blood red; Often inhabit the mountain stream and its nearby rivers. Because of its high protein content, it is nicknamed "Crab Assistant".
Strictly speaking, shrews are native to China, but the common crayfish on the market now are actually exotic species and cannot be called shrews. Biologists have listed it as an "invasive species in China".
Crayfish are native to the southern United States and northern Mexico. From northern Scandinavia to Australia, it is cultivated in the United States, Asia and Africa. Unlike most aquatic species, female crayfish hatch their eggs by themselves, so there is no need to spend money on artificial incubation. Once the original seed is put into the pond, crayfish can achieve self-maintenance and pest control, and it is not necessary to put the original seed into the pond after harvest. Crayfish are often mixed with other crops, especially rice. Those who escaped during the harvest season dug holes in the dam to survive. In the next season, a breeding population will be formed, living on surplus crops and other foods. At present, crayfish have spread to many areas of China, and become a large population in the wild.
The territory of China is over 5,000 kilometers from north to south and from east to west, spanning 50 latitudes and 5 climatic zones. This natural feature makes China vulnerable to invasive species. Most exotic species from all over the world are likely to find suitable habitats in China, among which crayfish is notorious.
Objectively speaking, China's understanding of the harm of exotic species is still largely limited to the serious economic losses caused by pests and diseases, and it has not realized or paid attention to the changes and destruction of local natural ecosystems by exotic species. Those species that have not caused serious economic losses, but are crowding out and replacing local species and changing local ecosystems, have not received enough attention. Therefore, the large-scale introduction of alien species intentionally or unintentionally in the process of many natural vegetation restoration will inevitably lead to the loss of rich and unique biodiversity in China, which is difficult to restore.
The harm of crayfish to the dam is determined by its burrowing habit. Its front end has a pair of claws like pliers, which can dig holes quickly and widely. Because they often live on the banks of rivers, reservoirs, ponds and paddy fields, the harm to dams may be greater than that of termites. Field investigation shows that crayfish mainly appear on the back of the dam. As long as there are puddles, ditches or very wet places, they will usually be found. It's easier to ask God than to send him. Crayfish breed very fast, and the fertile land where crayfish have been bred has been bitten to the ground and lost its breeding ability.
Crawfish, where are you from and where are you going? Is your injury only manifested in biology? No, of course not. A biology teacher in a middle school solved the last but terrible mystery for me-
Crayfish, as an invasive species, was first introduced in 1930s. More precisely, it invaded China with the Japanese invaders, and it was a biological experiment brought to China by fanatical Japanese militarists. Japanese introduced from the United States earlier, and the varieties introduced to China have been genetically improved. At that time, the Japanese were still using crayfish as a biological tool to treat urban sewage.
As we all know, Japan is an island country that lacks edible fresh water, and how to deal with the purification of fresh water is related to the lifeline of their country. Ishii, the executioner of the "73 1" bacterial unit, once invented a device for purifying fresh water, which won great attention and praise from the military. Crayfish entered China with the same historical background. Crayfish mainly live in ponds, ditches and other places, and have strong ability to survive and reproduce. With the decrease of natural waters, large-scale planting began. Because it has strong adaptability and can survive in heavily polluted water, the Japanese cultivated it and made biological improvement. Its main purpose is to treat urban sewage and use it to absorb heavy metal elements in sewage as the first green sewage treatment scheme. ...
Sadly, we regard it as delicious when it is someone else's garbage.
The food sources of wild crayfish are mainly plant straws, aquatic plants, snails, small miscellaneous fish, dead fish or similar corpses. Because crayfish have the habit of eating carrion, their bodies carry a lot of bacteria and toxic substances. In recent years, China's water pollution is very serious, and a large number of floating objects have accumulated in the Yangtze River basin. Although government departments have organized manpower and material resources to clean up these pollutants, these pollution sources still affect the living environment of aquatic organisms. So people who eat crayfish in this environment will have uncomfortable symptoms. It is reported that the sketch actor Zhao Benshan got into trouble for eating crayfish.
Then, a large number of farmed crayfish are transported from the south to the northern market for sale. Is the hemp we eat safe? The answer is no, the aquatic products market in big cities really needs to test the newly arrived crayfish, but it is not by the health and epidemic prevention station, but by the chemists in the professional market to carry out routine testing and inspection on the aquatic products samples sold every day, which can only ensure that crayfish carry harmful germs at a lower angle than wild crayfish.
Driven by the interests, many vendors in the farmers' market organize manpower to catch crayfish growing in the wild environment in the rivers in the south and transport them to the north, especially the Beijing market for sale. As we all know, crayfish will die soon after leaving their original living waters. Illegal traders will freeze dead shrimp overnight, and then reduce the price or pinch off the rotten shrimp head for sale. Bacteria breed on dead crayfish, and the toxins it produces can be imagined.
More importantly, the "Ma Xiaoer" in the summer night market is not only unknown, but also has more problems in processing. Large restaurants keep a large number of crayfish in large plastic pots. When the guests order, take it out directly, put it under the tap water, fry it and serve it. Insiders know in detail that most of the smaller food stalls are contracted by migrant workers who work and do business in other places. They have a short-term relationship with a store with a formal business license. Almost 65,438+000% employees do not have health certificates from the health and epidemic prevention departments. They often use large pots and pans to process crayfish, and then code them at the counter to attract customers, and some have overnight phenomenon (spicy and heavy materials cover up crayfish). In addition, as far as the night market in Beijing is concerned, the processed crayfish are all intact, and the shells and claws are intact. This looks beautiful and avoids the suspicion of being stale. Actually, it's not hygienic at all. Crayfish, whether farmed or wild, live in waters full of plankton, which is the "host" of biologists' parasites. The head of crayfish plays a filtering role. Because the pretreatment process is too simple, many plankton accumulate in the gills of the head. Friends who have eaten crayfish know that when you peel crayfish, you will see something similar to a shrimp line (mud sausage), which extends to the outlet of crayfish. The dirt in it is the waste that it has not excreted. Don't think that frying crayfish can kill parasites and bacteria in it. Crayfish is a crustacean aquatic organism and a carrier of paragonimiasis. If you eat raw or half-cooked crayfish, people may get paragonimiasis, ranging from cough, chest pain and hemoptysis to invasion of people's liver and gallbladder, muscles, eyes and even brain, and epilepsy or hemiplegia may also occur.
Apart from these phenomena, going back to the previous topic, it is still unknown what kind of concentration of heavy metal compounds in crayfish has reached. The routine detection of health and epidemic prevention departments is not technically possible at present, and the final result may be obtained with the help of high-level laboratories. I hope that some of the contents mentioned in this article can arouse the government's enough attention to this. For the sake of people's health, I call on the government to shut our mouths!
In order to prevent crayfish from becoming our new SARS, maybe it is time for China to say "no" to crayfish. (Sina. com)
References:
/foodiaryDetail.php？ Id= 155 184 can crayfish be eaten? To this end, life reporters conducted a special investigation.
The scientific name of crayfish was crayfish, which was introduced to China from Japan during World War II. At present, crayfish in China are mainly distributed in rivers, lakes and seas in the middle and lower reaches of the Yangtze River, and the number is about 60,000 tons.
In recent years, Dongting Lake has also become the main producing area of crayfish. At the same time, it is also a typical representative of the inland lake in the main crayfish producing area of China. Recently, we also made a special trip to Dongting Lake to inspect the growing environment of crayfish.
1. What is the growth environment of crayfish? What kind of environment is most suitable for the growth of crayfish?
In Yuanjiang section of West Dongting Lake, we found Laogan, a shrimp farmer. Lao Gan told us that crayfish will be active in the shallows every summer. In winter or when crayfish shell and breed, in order to protect themselves, crayfish will lurk in caves. From June to August every year, crayfish is the most "plump" time, and it is also the best time for people to catch and enjoy it. Green, shallow beach, this water area is where Lao Gan often catches lobsters.
Shrimp farmers say crayfish like to live in clean places, such as sewers, where crayfish will not grow up.
The survey shows that the rumor that crayfish grow better in the dirtier place is unfounded.
Second, are there many crayfish on the market at present?
Crayfish are omnivores, mainly eating animals. Small fish, shrimp, plankton, benthos and algae can all be used as its food. According to shrimp farmers, crayfish are very fertile, ovulating two or three times a year. It usually takes only 2 months from the hatching of shrimp eggs to the maturity of crayfish.
Shrimp farmers say that he can catch three or four hundred Jin when he is alone at most, but there are thousands of shrimp farmers like him in Dongting Lake waters. Every day, about 30 tons of crayfish are sent from Yuanjiang market to all parts of the country.
The water with shallow water plants is the favorite of crayfish, because it is not only their habitat, but also a hidden place for them to shell. In addition, crayfish also like to make holes, which is also very destructive. They often break through ridges and destroy dams. Combining these characteristics of crayfish, local shrimp farmers specially made a kind of shrimp catching tool-Tulongwang. Shrimp farmers set up a net hole in each section of Tulongwang, which is simple and convenient, but they can invite shrimps into the urn.
Shrimp farmers say that artificial farming is not needed because crayfish have strong reproductive ability.
The survey shows that wild crayfish can meet the market demand, and the cost is much lower than that of artificially cultured crayfish. Artificial culture of crayfish has no economic benefits. Therefore, there is no basis for saying that the environment for artificially breeding crayfish is not good.
3. Are there many crayfish caught in the river ditch?
June, July and August are the best seasons to catch crayfish in Dongting Lake every year. In late August, as the temperature of the lake dropped, crayfish began to dig holes at the bottom of the lake or on the shore, waiting for the next summer. At this time, the shrimp catching on the lake has gradually reached a low point, while the number of people catching shrimp in the river ditch has increased.
The tools for catching shrimp in the river ditch are very simple. Shrimp farmers usually only need a shovel to dig shrimp and a glove to catch shrimp.
Shrimp farmers say that the water in the cave is very clean, just like the growing environment of eels and loaches. The hole dug by crayfish is generally between 1.5 and 2 meters. When it gets cold in autumn, it is more difficult to dig crayfish in the river ditch, which is only six or seven kilograms a day.
The investigation shows that due to the cold weather, the time suitable for catching shrimp in the river ditch is very short. And there is not much economic benefit. Therefore, most of the crayfish currently on the market are crayfish caught in the lake area.
Fourth, how to distinguish the crayfish dug in the river ditch from the crayfish caught on the lake?
When we asked about the difference between lake shrimp and ditch shrimp, Lao Gan, a shrimp farmer, made a comparison between lake shrimp and ditch shrimp. The crayfish raised in clear water are bigger, the shrimps in the lake are lighter and redder, and the shrimps in the ditch are darker.
Tip: Because of the different growth environment of crayfish, it is recommended to eat crayfish produced in the lake area. The crayfish produced in the lake area are characterized by bright colors, large individuals and consistent head and trunk proportions.
At present, crayfish sold in China's market are mainly produced in Dongting Lake, Poyang Lake, Honghu Lake and Hongze Lake. Taking Dongting Lake as an example, the daily output in peak season is about 30 tons, and it is about 3,600 tons in four months in 5678. Together with other lake areas, the total output of these main producing areas in peak season is about 1.7 million tons. This is basically the same as the current annual consumption of 20,000 tons of crayfish in China.
Because of the high content of protein in crayfish, the content of trace elements such as zinc, iodine and selenium in shrimp meat is also higher than other foods. And it tastes good, so crayfish have been very popular in many cities in recent years. Some places even set off a "red storm" of summer catering. But our reporter also has some concerns, because the situation in some crayfish-producing waters is not optimistic.
When investigating the waters of Dongting Lake, we found a stone tablet standing in Yuanjiang aquatic products trading market, which said, "There is schistosomiasis here, so it needs to be protected when entering the water." So if crayfish live in such waters, is it possible to become a parasitic host of schistosomiasis? To this end, we visited Yuanjiang Health and Epidemic Prevention Bureau. The director told us that Schistosoma japonicum is only parasitic among snails, and there is no evidence that Schistosoma japonicum is parasitic among crayfish. But experts also confirmed that crayfish is indeed the intermediate host of paragonimiasis.
5. Could crayfish carry parasites and heavy metals?
We sent crayfish brought from Dongting Lake waters and crayfish bought from Beijing market to the Institute of Tropical Diseases of Beijing Friendship Hospital for testing.
The investigation shows that there is no evidence that crayfish carry schistosomiasis, paragonimiasis or are polluted by heavy metals. In addition, both schistosomiasis and paragonimiasis are afraid of high temperature. So crayfish can be safely eaten as long as it is cooked at high temperature.
6. How do shrimp farmers make crayfish?
Rinse it first, soak it in cold water for an hour or two, and then remove the head, breastplate, head and cheeks of the shrimp. Next, take the shrimp sausage out of the tail fan. After cutting the shell of the crayfish abdomen, finally, scrub the crayfish comprehensively. As for cooking methods, it depends on personal preferences, and so on.
Tip: Shrimp farmers know the habits of crayfish, and the method of making crayfish is scientific, which can be used for reference.
7. There are many frozen products of crayfish or shrimp tails of crayfish ready for sale in the market. Are these products fresh?
During the investigation, we also found some similar situations.
Phenomenon 1: Some shrimp vendors pinch their heads and leave their tails as frozen products to sell.
Phenomenon 2: In some markets, shrimp vendors are selling dead crayfish.
Tip: Be careful when buying and eating frozen crayfish or prefabricated shrimp tails of unknown origin. Because these products may not be very fresh.
In order to make everyone enjoy crayfish more healthily, here are some suggestions.
Suggestion 1: Make your own crayfish. It is suggested that crayfish should be soaked in clear water for two to three hours, then washed clean and cooked at high temperature before eating.
Recommendation 2: Because the protein content of crayfish is high, and protein will do great harm to human health after decay, it is suggested that crayfish must be cooked and eaten once. However, don't eat too much crayfish, because eating too much protein can easily lead to indigestion.
Suggestion 3: Because it takes time to brush and cook crayfish, crayfish in most restaurants are prepared in advance. Before eating crayfish, it is best to look at the body of the fried crayfish. If the tail is curled, it means it was alive before it was put into the pot. If the tail is straight, it means that the shrimp has died before it is put into the pot. Remember, dead crayfish can't be eaten.
References:
/life/200309 17/ 100233 . shtml