The scientific name of crayfish is Crayfish crayfish, also called red crayfish or freshwater crayfish. Professor Cai Shengli of the School of Fisheries, Shanghai Fisheries University said that crayfish are native to North America. In 1918, Japan introduced crayfish from the United States as bait for raising bullfrogs. During World War II, crayfish was introduced to my country from Japan and has now become an important resource among freshwater shrimps in my country. It is widely distributed in provinces and cities in the middle and lower reaches of the Yangtze River.
Professor Wang Xichang from the School of Food, Shanghai Fisheries University said that crayfish have a high protein content, accounting for about 16% to 20% of the total, and the fat content is less than 0·2%. The shrimp meat contains zinc, iodine, The content of trace elements such as selenium is higher than that of other foods. In addition, crayfish can also be used as medicine, which can reduce phlegm and relieve cough, and promote wound healing after surgery.
Dialogue with Crayfish CCTV International September 17, 2003 10:07
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A few days ago, we received Letter from a viewer. The viewer said in the letter that he wanted to report the crayfish, and also wanted our help in urging everyone to stop eating crayfish. He said that most of the crayfish we eat now are grown in field trenches and feed on dirt and garbage. The meat contains a lot of heavy metals and even parasites.
Listening to this audience member, it is really creepy. Many people love to eat spicy crayfish, and in Guijie Street, Beijing, the spicy crayfish eaten every day is named "tons" "To calculate. Think about it, on the one hand, it is a delicacy, but on the other hand, many experts and scholars have stood up against eating crayfish. So where does crayfish come from? Can crayfish be eaten? To this end, "Life" reporters conducted a special investigation.
The scientific name of crayfish is Crayfish crayfish. During World War II, it was introduced to my country from Japan. At present, crayfish in my country are mainly distributed in rivers, rivers and lakes in the middle and lower reaches of the Yangtze River, with a quantity of about 60,000 tons.
“Eight hundred miles of Dongting is picturesque.” In recent years, the waters of Dongting Lake have become the main source of crayfish. It is also a typical representative of inland lakes, the main producing area of ??crayfish in my country. In order to investigate the growth environment of crayfish, we recently made a special trip to Dongting Lake.
1. What is the growth environment of crayfish? What kind of environment is most suitable for the growth of crayfish?
In the Yuanjiang section of West Dongting Lake, we found shrimp farmer Lao Gan. Lao Gan told us that every summer, crayfish will be active in the shallows. In winter or when crayfish shed their shells and reproduce, crayfish will lurk in caves to protect themselves. From June to August every year, crayfish are at their most plump, and this is also the best time for people to catch and enjoy them. With green grass and shallow beaches, this water area is where Lao Gan and the others often fish for lobsters.
The shrimp farmer said that crayfish like to live in clean places. In places like smelly ditches, crayfish do not grow very big.
Survey shows: The rumor that crayfish grow better in dirtier places is unfounded.
2. Are most of the crayfish currently on the market artificially farmed?
Crayfish are omnivores and mainly eat animals. Small fish, shrimps, plankton, benthic organisms and algae can be used as its food. According to shrimp farmers, crayfish have a strong reproductive capacity and will ovulate two to three times a year. It usually only takes 2 months from the hatching of shrimp eggs to the maturity of crayfish.
The shrimp farmer said that he can catch up to three to four hundred kilograms per person, and there are probably thousands of shrimp farmers like him in the waters of Dongting Lake. Every day, about 30 tons of crayfish are shipped from Yuanjiang Market to all parts of the country.
Waters with shallow water plants are the favorite of crayfish, because this is not only a place for them to live, but also a hidden place for them to shed their shells. In addition, crayfish also like to drill holes, and their destructive capabilities are also very powerful. They often penetrate fields and destroy embankments. Combining these characteristics of crayfish, local shrimp farmers have specially made a shrimp fishing tool - the Earth Dragon King. The shrimp farmers set a mesh hole in each section of the Earth Dragon King, which is simple and convenient but can invite shrimps into the urn.
Shrimp farmers say there is no need for artificial breeding because crayfish have a strong reproductive capacity.
The survey shows that wild crayfish are enough to meet market demand, and the cost is much lower than artificially cultured crayfish.
There is no economic benefit to artificially raising crayfish. Therefore, there is no basis for saying that the environment for artificially raising crayfish is harsh.
3. Are there many crayfish caught from the ditch?
June, July, and August every year are the best seasons for fishing crayfish in Dongting Lake. In late August, as the temperature of the lake water drops, crayfish begin to dig caves on the bottom or shore of the lake to live. Looking forward to next summer. At this time, the shrimp fishing work on the lake has gradually declined, but there are more and more people fishing for shrimp in the river ditch.
The tools for catching shrimp in river ditches are very simple. Shrimp farmers usually only need a pair of shovels for digging and a pair of gloves for catching shrimps.
The shrimp farmer said that the water in the cave is very clean and the environment is the same as the growth environment of eels and loaches. The holes dug by crayfish are usually between 1.5 and 2 meters. In addition, the weather gets cooler after autumn, so it is quite laborious to dig out crayfish in the river ditch. It only weighs six or seven kilograms a day.
The survey shows that due to the cooler weather, the time suitable for fishing in river ditches 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.
4. How to distinguish crayfish dug from river ditches from crayfish caught on the lake?
When we asked about the difference between lake shrimp and ditch shrimp, shrimp farmer Lao Gan made a comparison between lake shrimp and ditch shrimp. The crayfish raised in clean water are larger, the shrimp in the lake are lighter and redder, and the shrimp in the ditch are darker.
Tip: Due to the different growth environments of crayfish, it is recommended to eat crayfish produced in the lake area. The characteristics of crayfish produced in the lake area are: bright colors, large individuals, and relatively consistent head and trunk size ratios.
The crayfish currently sold on the market in my country are mainly produced in Dongting Lake, Poyang Lake, Honghu Lake, Hongze Lake and other lake areas. Taking Dongting Lake as an example, the daily output in the peak season is about 30 tons, and in four months it is about 3,600 tons. Together with several other lake areas, the total output of these major producing areas in the peak season is about 17,000 tons. This is basically the same as the current national annual consumption of crayfish of 20,000 tons.
Due to the high protein content in crayfish, the content of zinc, iodine, selenium and other trace elements in shrimp meat is also higher than that of other foods. It also tastes good, so crayfish has become very popular in many cities in recent years. Some places have even set off a "red storm" of summer dining. But our reporter also has some worries, because the situation in some waters where crayfish are produced is not optimistic.
While surveying the waters of Dongting Lake, we found that there was a stone monument erected at the floating aquatic products trading market in Yuanjiang City, saying, "There are schistosomiasis here, and protection is required when entering the water." So if crayfish survive in such waters, is it possible to become a host for schistosomiasis? To this end, we visited the Yuanjiang Municipal Health and Epidemic Prevention Bureau. The director told us that schistosomiasis only lives in oncomelania, and there is no evidence that schistosomiasis exists in crayfish. But experts also confirmed that crayfish are indeed the intermediate host of paragonimiasis.
5. Is it possible that crayfish carry parasites and heavy metals?
We sent crayfish brought from Dongting Lake waters and crayfish purchased from the Beijing market to the Institute of Tropical Diseases of Beijing Friendship Hospital for testing.
The investigation shows: There is currently no evidence that crayfish carry schistosomiasis, paragonimiasis or are contaminated with heavy metals. In addition, both Schistosoma and Paragonimus are afraid of high temperatures. Therefore, crayfish can be eaten with confidence as long as they are cooked at high temperature.
6. How do shrimp farmers prepare crayfish?
First, rinse and soak in cold water for one to two hours, then remove the head and breastplate, head and gills of the shrimp. Next, remove the intestines from the tail fan of the shrimp. After cutting the shell of the crayfish belly, finally scrub the crayfish thoroughly. As for the cooking method, it depends on personal preference.
Tip: Shrimp farmers have a good understanding of the habits of crayfish, and their methods of making crayfish are scientific and can be used as reference.
7. There are many frozen crayfish or prepared crayfish tails for sale on the market. Are these products fresh?
During the investigation, we also discovered such situations.
Phenomena 1: Some shrimp vendors cut off the heads and tails of dead crayfish and sell them as frozen products.
Phenomena 2: In some markets, there are shrimp sellers selling dead crayfish.
Tip: Be cautious when buying and eating frozen crayfish or prepared shrimp tails of unknown origin. Because these products may not be fresh.
In order for everyone to enjoy crayfish more healthily, here are some suggestions.
Suggestion 1: Make your own crayfish. It is recommended to soak the crayfish in water for two to three hours, wash them clean, and cook them at high temperature before eating.
Suggestion 2: Since crayfish has a high protein content, and the rotten protein will cause great harm to human health, it is recommended that the crayfish must be eaten at one time after it is cooked. However, don’t overeat crayfish, as too much protein can easily cause indigestion.
Suggestion 3: Since washing and cooking crayfish is time-consuming, most restaurants have their crayfish prepared in advance. Before eating crayfish, it is best to take a look at the body of the fried crayfish. If the tail is curled, it means it was alive before being put into the pot. If the tail is straight, it means the shrimp is dead before it is put into the pot. Remember, dead crayfish cannot be eaten.
Crayfish
●Buy
The most important thing is to choose crayfish. The best time to eat crayfish is from May to October. The meat is yellow and full of fat. The three sections on the big claw are made of elastic teeth and snow muscles stuffed from head to tail.
Check whether the crayfish is in clear or muddy water. If you look at the back, it is bright red and clean, which is acceptable. Then open it and look at the villi on its abdomen and the vellus hair on its claws. If it is white and neat, it is basically It is raised in clean water.
After all, crayfish eat the carcasses of humus animals, and more and more bacteria and toxins will accumulate in the body, so we try to buy lobsters that have just grown up. If they are too small, they will not be eaten after all. Tasteless. This requires you to look at the skin color. Old lobsters may be red to black or red with an iron-blue tint, while young lobsters are bright red and have a natural and healthy luster. When you touch its shell with your hands, you will see that the iron-hard ones are undoubtedly old, while the elastic ones like fingernails have just grown and shed their shells, so we have to buy soft-shell ones.
●TIE
In fact, the lobsters in the hotel just use the strong smell of thirteen incense or something to cover its fishy smell. They may be trying to save time, or more likely to make the lobster look better. Complete and beautiful, neither cleaned the lobster properly.
We Jiangsu people usually eat crayfish like this:
1. Cut off most of the head shell, and use scissors to pick out the black sand from the exposed head to the back. stomach pouch;
2. Cut off the shells of the gills on both sides, and then cut off the whiskers diagonally;
3. Pull the carapace in the middle of its tail with your hands. Pull along the trend and pull out the black intestines;
4. Make a vertical cut on the back to make it more delicious (this trick is optional, it depends on each person's preference);
5. Use a toothbrush under tap water to rinse it up, down, left, and right. Important reminder: Be careful not to rinse away the yellow shrimp! Then drain.
●Shaking
Ingredients: shallots, ginger, garlic, Sichuan peppercorns, dried chilies, fennel, bay leaves, cinnamon, vegetable oil, Shaoxing rice wine, soy sauce, salt, sugar, black pepper , MSG;
Cooking method:
1. It is best to use a large iron pot, which can fry more. Generally, no one uses a small plate to fry lobster;< /p>
2. Heat the pot, add more oil, because this dish is mainly for frying, there is not much oil, it will burn immediately, how can it be done;
3. Onions are knotted, ginger, Slice the garlic and sauté until fragrant, then add some dry spices such as Sichuan peppercorns and dried chili peppers. The chili peppers need to be cut to taste;
4. Put the shrimps into the pot, stir-fry over high heat, and pour a spoonful of rice wine , add salt after 1 minute, so that the flavor will be infused, just keep stir-frying, add soy sauce, sugar, stir-fry again, add half a bowl of water, and cover;
5. Open after three or four minutes Cover, remove the onion knots, add MSG, pepper, and green onions and bring to the pot.
What are you waiting for next? Grab some hand-caught lobster while it’s hot. The shrimp is juicy and spicy, and you won’t forget it once you eat it.