Tuna is also called tuna. Tuna is called tuna in Hong Kong and translated into Asian winter fish in Macau. Most of them are tuna. The flesh color of tuna is red, because the muscle of tuna contains a lot of myoglobin. Some tuna, such as bluefin tuna, can use the metabolism of swimming muscles; Make the temperature of blood in the body higher than the external water temperature. This physiological function enables tuna to adapt to a wide range of water temperature, so that it can survive in lower temperature waters.
Swim fast, the instantaneous speed can reach 160 km, and the average speed is about 60-80 km. Tuna is a tropical-subtropical marine fish, distributed in the Indian Ocean, the central Pacific Ocean and the central Atlantic Ocean. Tuna has a long way to go. In the past, tuna from California, Japan, was found off the coast of Japan.
There are 8 species of tuna, most of which are huge. The largest species is 3.5 meters long and weighs 600 to 700 kilograms, while the smallest species is only 3 kilograms. Tuna is very fertile. A 50 kg female fish can lay as many as 5 million eggs every year. Tuna is a very popular seafood with high economic value. Due to the policies and activities of various countries and the overfishing of fishermen, its population has been threatened, the most obvious being the blue fin golden gun. Therefore, tuna fishing has been controlled internationally, but the results are quite limited.
Chinese name: tuna Latin scientific name: Thunnus thynnus(Linnaeus) alias: tuna, tuna kingdom: animal kingdom: Chordata subfamily: Vertebrate subfamily: Skeletal fish order: Perciformes: Tuninae: Tuna genus: English name: Tuna morphological characteristics, distribution range, habit characteristics, body temperature interpretation, medicinal value, species division, and so on. Ma Su tuna, silver carp, fishing method, processing method, deck treatment, chilled technology, edible value, nutrition, taste, related dishes, nutritional components, suitable for people, precautions, fishing cases, morphological characteristics: body length, thick and round, streamlined, tail base gradually tapering backwards, tail fin forked or crescent-shaped. There are obvious ridges on both sides of the caudal stalk, and a row of small fins behind the dorsal fin and gluteal fin. It is torpedo-shaped with a slightly round cross section. Tuna is also very strange in shape. Its entire breastplate is streamlined and extends along the head, as if it were a unique balance plate, which can adjust the water flow. In addition, the tuna's tail is half-moon, which enables it to sprint forward quickly in the sea. Strong muscles, crescent-shaped tail fin, breastplate with gradually expanding scales on the shoulders, dark on the back and silvery white on the ventral side, usually with rainbow-colored light and stripes. Another feature is that there is a well-developed vascular network under the abdomen, which can be used as a thermoregulation device for long-distance slow swimming. The largest and rarest tuna is bluefin tuna, also known as black tuna, which can grow to about 4.3 meters and weigh 800 kilograms. From the commercial point of view, the most important species of tuna are: silver carp (Katsuwonus pelamis or Euthynnus pelamis), with longitudinal stripes on the abdomen, about 90 cm long and weighing about 23 kg. T. thynnus is a precious fishing species, with small yellow fins and silvery white spots or stripes. The bottom surface and ventral surface of Mao Shi Cone stinkbug are silvery white, with colorless horizontal lines and colorless dots arranged on it. The first dorsal fin is yellow or blue; The gluteal fin and caudal fin are dark yellow with black edges. T. alalunga is a worldwide fish, weighing about 36 kilograms, with blue flashing stripes on its side. Baiji dolphin is a precious food and fishing fish, which is distributed all over the world and weighs about 182 kg, especially with yellow fins and golden stripes on its side. Obese voles are strong and have big eyes, which are distributed all over the world. It is about 2m long and weighs 136kg. The distribution range of tuna is also called tuna, and the Chinese world is also called "Tunna". It is a warm-water migratory fish in the ocean, mainly distributed in the middle and low latitudes and widely distributed in the Pacific Ocean, Atlantic Ocean and Indian Ocean. China's East China Sea and South China Sea are also distributed. The most similar fish to tuna is silver carp, and the simplest way to distinguish them is that silver carp has 4-6 black longitudinal bands in its abdomen, while other similar fish, such as rudder carp and fox carp, all have dark longitudinal bands. Like tuna, fish don't have any black spots or dark longitudinal stripes. The ventral fin of tuna is obviously longer than that of rudder and fox. Scientific research shows that most tuna inhabit the sea area with water depth of 100-400 meters, while juvenile fish, yellowfin tuna and silver carp inhabit the surface waters of the ocean, generally less than 50 meters, and adult fish of bigeye tuna and yellowfin tuna inhabit the deeper waters. Its spawning period is very long, and the spawning sea area is very wide, which makes tuna spawn in all sea areas all year round, with strong fecundity, and consumers all over the world can enjoy its delicious food. Habit characteristics of tuna The tuna body is spindle-shaped and torpedo-shaped, and the cross section is slightly round. Strong muscles and crescent-shaped tail fins, scales have degenerated into small round scales, suitable for fast swimming. Generally, the speed is 30-50 kilometers per hour, and the top speed can reach 160 kilometers per hour, which is faster than the fastest animals on land. If tuna stops swimming, it will suffocate. The reason is that tuna always breathes oxygen through its gills with its mouth open, so it can only swim at high speed all its life, even at night, it can only slow down its swimming speed and reduce its metabolism (this breathing method of breathing water directly through its gills with its mouth open is called impact breathing, and tuna belongs to impact breathing. )。 Tuna's belly is lighter than its back, so that when it looks up from the sea, its body color is similar to that of the sea; Tuna can swim thousands of kilometers and cross the ocean, so it is called "a kind of fish without national boundaries". According to scientists' research, tuna is the only large fish that can swim long distances and quickly. Experiments show that tuna can swim up to 230 kilometers a day. Tuna has an interesting habit. It is one of the fastest swimming marine animals, and only extremely ferocious sharks and dolphins can compete with it. Tuna can swim at full speed up to 55 nautical miles per hour. In order to supplement the energy consumed by constant swimming and vigorous metabolism, tuna must keep eating. A catty of tuna will eat 18% of its body weight in one meal, which is equivalent to a person weighing 150 jins eating two big cocks with bones in one meal. The gill muscles of tuna have degenerated, so it is necessary to keep swimming to let fresh water flow through the gills to get oxygen. If tuna stops swimming, it will die of hypoxia and suffocation. When the tuna swims at full speed, the fin will shrink into the body to reduce the resistance and move forward like a cannonball. Most fish are cold-blooded animals, while tuna are warm-blooded animals with a body temperature of 93-95 degrees Fahrenheit. High body temperature and vigorous metabolism make tuna react quickly and become a super hunter. Tuna has a variety of eating habits, and marine animals such as squid, crab, eel and shrimp are all its delicacies. Tuna's body temperature explains that tuna's body temperature is higher than the surrounding water temperature because it has skin, muscles and blood vessels on both sides of its body. After careful study by scientists, the body temperature of tuna is 9℃ higher than the surrounding water temperature. The muscle contraction strength of this tireless fast swimmer is the main reason for their body temperature rise. A large number of vascular network clusters along the strong muscles and skin on both sides of the tuna spine indicate that the metabolism of these parts is particularly strong, so the fish meat of tuna is like beef and purple. Among them, heme is high in content, low in fat and high in protein, so it has high nutritional value. With the rapid development of modern society and the improvement of material living standards, people pay more and more attention to health. At the same time, tuna is considered as a nutritious and healthy modern food. More and more favored by developed countries such as Europe and America. The top ten functions of this kind of food are as follows: First, tuna is a healthy food for women to lose weight. Tuna meat is low in fat and calories, as well as high-quality protein and other nutrients. Eating tuna food can not only keep slim, but also balance the nutrients needed by the body, which is an ideal choice for modern women to lose weight easily. Second, it can protect the liver and strengthen liver function. The incidence of a series of liver diseases caused by the intense pace of life, great work pressure and excessive fatigue is increasing day by day. Third, prevent arteriosclerosis arteriosclerosis is a threat to the lives of middle-aged and elderly people. Eating tuna food can reduce blood fat, dredge blood vessels and effectively prevent arteriosclerosis. Fourth, effectively reduce cholesterol content. EPA, protein and taurine in tuna have excellent cholesterol-lowering effects. If eaten regularly, they can effectively reduce the malignant cholesterol in the blood and increase the benign cholesterol, thus preventing diseases caused by high cholesterol content. 5. Tuna oil can activate brain cells and promote internal activities of the brain. It is a high-quality brain-nourishing health care product. Tuna is rich in DHA, which is an unsaturated fatty acid and cannot be produced by human beings. It is one of the essential nutrients for normal brain activity. DHA can enter the brain through the blood-brain barrier, increase and prolong the synapses of brain nerve cells, thus increasing brain capacity and enhancing memory and understanding. Regular consumption is beneficial to the regeneration of brain cells, improving memory and preventing Alzheimer's disease. In addition, DHA can soften the retina, improve retinal reflex function, strengthen vision and prevent myopia, while EPA can promote DHA to play a role in the body. Sixth, it can effectively prevent iron deficiency anemia. Iron is an indispensable element for human body. The blood of tuna is rich in iron and vitamin B 12, which is easily absorbed by human body. Regular consumption of iron can prevent anemia and can be used as an auxiliary treatment food for anemia. Seven. Provides essential amino acids for human body. Tuna protein is rich in amino acids. Eating tuna can not only enjoy delicious food, but also supplement amino acids through non-pharmaceutical means, which is beneficial to health. Eight, contribute to human metabolism, especially the ideal choice for children's food during the growing period. Bone, skin, hair, blood and other human tissues are inseparable from protein. Tuna protein has incomparable efficacy with meat protein and is the best nutrition for children's natural growth. Nine, maintain the normal water standard of the human body. Regular consumption of tuna can remove excess salt in the body, balance the water content in the body and maintain normal water indicators. Ten, it is the best companion of green vegetables. There are many ways to eat tuna, and it tastes better with green vegetables. Species classification In biological classification, tuna in a broad sense refers to about 30 species of fish in Sparidae, Swordfish and Swordfish. The species with great economic value are bluefin tuna, Ma Su tuna, bigeye tuna, yellowfin tuna, albacore tuna and bonito, among which bluefin tuna, Ma Su tuna, bigeye tuna and yellowfin tuna live on food. Yellow fin tuna, bigeye tuna and albacore tuna are the main objects of longline fishing, and bonito is the main object of pole fishing. Yellowfin Tuna (English: Yellowfin Tuna): The fish is spindle-shaped, with a slightly flat side, a small head, a slender tail and pink flesh. The back of the body is blue-blue, the side is light gray, with a little yellow and a little horizontal. The second dorsal fin and anal fin of adult fish and the small fin behind them are bright yellow. The first dorsal fin and ventral fin are yellow. Body length1-3m, which varies with different sea areas. Generally, it can reach 2 meters and weigh more than 100 kg. Yellow fin tuna has a wide range of feeding habits, mainly squid, surface fish and large crustaceans. As a long-distance migration, its migration is related to the seasonal variation of current. In the tropical rainy season, it swims away from the lighter coastal waters to the high salinity waters. Yellow fin tuna is widely distributed in the equatorial waters of the three oceans and is a representative species in tropical waters. The common water depth of yellowfin tuna is160m, the water temperature is 20-28℃, and the maximum swimming speed is 90km/h ... Yellowfin tuna accounts for 35% of the global tuna production. Most of them are used for canning, and fresh and frozen products are also growing. Yellow fin tuna has been in a state of rational development. Atlantic bluefin tuna (English: Atlantic bluefin tuna) is the largest species of tuna, also known as blackfin tuna. Short, strong, slender body with tapered tail fins crossed; From the bottom of the body to the side, the color is bright, the upper body is dark blue, the fins are dark, the fins are yellowish, and the tail stalk ridge is black. The whole body is covered with scales, the mouth is quite big, the eyes are not big, the pectoral fin is short, and the end is smaller than the center of the first dorsal fin, which is the biggest feature of this species. The body length is generally 1-3 meters, and the largest is more than 3 meters long and weighs more than 700 kilograms. Bluefin tuna often groups with 50-60 fish, and some fish groups exceed 1000. The habitat water layer is from the water surface to 50 meters deep, and the optimum water temperature is 65438 00-20℃. The bait is mainly herring, sardines, mackerel, squid and crustaceans. The average size of bluefin tuna is 200-400 kg. The catch is less than 1% of the global tuna catch. This kind of tuna grows slowly, is high in fat, delicious and expensive, and is mainly suitable for high-grade sashimi. Japan's major wholesale markets specializing in aquatic products, fruits and vegetables ushered in the first trading day of 20 1 1. At Tsukiji Market in Tokyo, a bluefin tuna from Toi, Hokkaido, became the "first tuna in Japan" with a weight of 342 kg. The final transaction price was 32.49 million yen, setting a record for the auction price of a single tuna. This is the highest auction price of a single tuna since Japan 1999 began to count tuna prices, setting a new record of 200 1 year. At that time, the transaction price of "Japan No.1" was 20.2 million yen, which was the first time that the tuna produced in Hokkaido was auctioned at the highest price in history. 10/222kg13,65438+ In Tsukiji Market, Tokyo, Japan's largest aquatic product market, a sushi restaurant spent 65438+55 million yen (about100000 RMB,1). This price broke the highest price record of 20 12 and set a new historical record. (Almost three times the previous record) The previous record of tuna auction was set in 20 12, which was 56.49 million yen (US$ 650,000), also obtained by Jiemu Village. 201510.5, Tokyo, Japan, the first auction was held in Tsukiji Central Wholesale Market in the early morning, and Nishimura Company won a bluefin tuna produced in Aomori Prefecture at the highest price of 45 1 10,000 yen. Bigeye Tuna (English: bigeye tuna), also known as chubby tuna and accessory tuna, is about 1.5-2.0 meters long, the heavier one is above 100 kg, generally 160-350 kg. The back of the body is blue, and the side abdomen is silvery white. The meat is pink and a little soft. The pectoral fin is very long, and its end is very sharp, reaching below the second dorsal fin, which is also very narrow, close to the height of the first dorsal fin. This kind of fish is gray, full of fat, with a short tail and significantly larger head and eyes. Big-eyed tuna lives in deep water, the water depth can reach 200-300 meters, and mature individuals lives on the surface. It mainly feeds on deep-sea fish, mainly small fish, squid and large crustaceans. The maximum swimming speed can reach 100 km/h, and the catch yield of bigeye tuna is low, but the price is high and the development potential is great. According to the statistics of relevant departments, the wholesale price of frozen tuna (Thunnus obesus), which consumes the most, has dropped by 20% compared with the same period. The fishing boats in Taiwan Province Province that supply sashimi to Japan have fished bigeye tuna in the Indian Ocean again since 20 12, and the number of them entering the Japanese market is also increasing. On the other hand, the quality of tuna is uneven. Some analysts believe that the current situation of oversupply will continue.
Big-eyed tuna is a mid-range product in tuna. Frozen tuna is mainly provided by Japanese, Taiwan Province and Indonesian fishing boats after catching tuna all over the world. The number of frozen bigeye tuna entering the Tokyo Central Wholesale Market exceeds 23,000 tons, accounting for nearly 60% of the total tuna. As high-grade ingredients, the wholesale price of black tuna and southern tuna is basically around 2,000-3,000 yen (about 160-240 yuan RMB), while that of bigeye tuna is around 1000 yen (about 80 yuan RMB). Albacore tuna (English: Longfin Tuna) has a dark blue back, silvery white sides and ventral sides, and a uniform body color. Body length 1 ~ 1.5m, weight about 15kg. Large individuals can reach 45 kilograms. Pink flesh, knife-shaped pectoral fins, extremely long, longer than the head are the most striking features of this species. Tuna albacore tuna is mainly distributed in the water layer of 90-150m during the day, sometimes as deep as150-200m, and it is distributed in the near surface at night. The suitable temperature range of albacore tuna is 14-20℃. The bait is mainly sardines and crustaceans. The output of albacore tuna accounts for about 7% of the total tuna output, and most of it is used for canning. Ma Su tuna (English: Southern bluefin tuna), also known as Southern Bluefin and Southern Bluefin Tuna, is a kind of fish that lives in the upper and middle waters of the ocean, distributed in the temperate and cold oceans of the Atlantic Ocean, Indian Ocean and Pacific Ocean, mainly concentrated in the waters between 30 S and 50 S, close to 60 S, and belongs to oceanic high migration. Tuna in Ma Su is generally 160 cm long, with a maximum length of 245 cm and a maximum weight of 260 kg. Sushi shops often make sushi with high-quality fat fish. Bonito, also known as bonito, swallow, Ogawa, Chaiyu and swallow tiger, belongs to the family Sparidae of Perciformes. Distributed in the warm waters of the global ocean. Body length is 40-70 cm. The maximum body length can reach 1 1 1 cm. The maximum weight can reach 34.5 kg. The body is spindle-shaped, with flat side, dark back, white abdomen, 4~ 10 dark blue longitudinal stripes, pointed mouth, and most of them are scaleless. Living in temperate and tropical seas, seasonal migration. It is an important edible fish, mostly used as sashimi (sashimi) and fish floss. There are two kinds of tuna fishing methods. One is longline fishing, which mainly catches bluefin tuna, Ma Su tuna, bigeye tuna, yellowfin tuna and albacore tuna living in deep water, weighing more than 20kg. Another fishing method of tuna surface fishing gear is the surface fishing gear fishing method, which includes purse seine, rod fishing and dragline fishing. Tunas inhabiting the ocean surface are mainly small yellowfin tuna, bigeye tuna and bonito, and their weight ranges from 5- 10 kg. Treatment method Deck treatment 1. Avoid fish jumping: after the fish is on deck, it should not be allowed to jump, so as not to cause blood stasis in the body. Congestion can cause extensive muscle damage, especially in the abdomen. The treatment method is: put it on the carpet, hold the fish eye with both hands, or hammer the fish head, but be careful not to break it, and then bleed immediately. 2. Tail cutting: generally use a sharp knife to cut off the dorsal fin between the penultimate third and sixth sections. For larger fish, it should be between the fourth and fifth section from the bottom to prevent the tail from being too thin. 3. Cut off the blood vessels on the back of pectoral fin: Tuna usually has two blood vessels on the back of pectoral fin. After separating from pectoral fin, cut off two blood vessels. The cutting knife is 5 cm deep and 4 cm long, and the cutting degree should be appropriate. If the knife cuts too deep, blood will invade the internal meat, causing waste. Even if the fish has died in the water, the above actions must be carried out. 4. Cut off the head artery before the heart: cut off the head artery before the heart, wash the fish with seawater to prevent the fish from rising in temperature, and then bloodletting surgery. Bleeding cuts a hole in the inner membrane of fish gills, and the seawater is poured in with a water pipe until there is basically no blood. Whether the blood is completely drained depends on the tail. 5. Puncture on the back of the brain: Puncture the needle after the blood drainage treatment is completed. This operation aims to destroy the cartilage of the fish brain and make the fish in a state of death. The pin is inserted into an internal point or depression of the head, or the top of the head above the fisheye. 6. Viscera removal and gill removal: cut the fish's viscera from * * to pectoral fin with a sharp knife and rinse it with seawater. During the operation, it should be noted that a layer of membrane attached to the inner wall of abdominal cavity should also be taken out, and the abdominal cavity should be washed with seawater to cut gills. Cut the periosteum of fish gill along the edge of fish gill, and cut off part of gill. When removing gills, the piece cut behind the gills should be as large as possible, and it is best to flatten the knife along the inside of the gills until it touches the bones. After removing the gills, chop off the miscellaneous meat attached to the bones in the gills with a spoon, but don't scrape the meat in the gills. 7. Washing: When washing fish, brush it from end to end, then take a sea bath, and then make an ice coat from the preparation room to the freezer to keep it frozen, so that commercial fish can meet the requirements of high quality and high price. Iced fresh technology 1. Treatment of bilges and bulkheads: The bilges and bulkheads should be covered with 30cm ice, the fish should be placed 30cm away from the bulkheads, and the gaps should be filled with ice. 2. Put the ice in the fish's mouth into the stomach and stuff it in. 3. Placement: The fish body is laid flat with a spacing of 30 cm, and ice cubes are placed in the middle. Each layer of fish should also maintain a 30 cm ice layer, and the fish should be staggered between layers to form a triangle with the head and tail upside down. After the arrangement, use frozen fish and cover it with ice, so that the process of freezing fish is over. 4. Knock and cover the ice twice: Generally, before freezing the fish the next day, the ice of the fish frozen the day before should be broken again, covered with a layer of ice, and then frozen. 5. The temperature of chilled fish cabin should be controlled between 0-2℃, and the highest temperature should not exceed 5-6℃. The shelf life of chilled fish is 12 days, and 14 days is the limit. If it exceeds 14 days, it will gradually deteriorate. The deep processing steps of tuna are thawing, cooking, peeling, head and tail removal, viscera removal and gills removal, segmentation and packaging. Edible value nutrition because tuna must swim fast all the time to maintain its body supply, and it only moves in the depths of the ocean, and its meat is tender and delicious, free from environmental pollution. It is a rare healthy food for modern people. The content of protein is as high as 20%, but the fat content is very low, commonly known as sea chicken, which has high nutritional value. Fatty acids in fish are mostly unsaturated fatty acids, which contain complete amino acids, including 8 kinds of amino acids needed by human body. It also contains vitamins, rich minerals and trace elements such as iron, potassium, calcium, magnesium and iodine. EPA, also known as OMEGA3-3, is a unique nutrient for tuna. Tuna Tuna is at the top of the food chain, and its content of heavy metals and mercury is higher than other marine fish. Eating too much equals chronic suicide. Tuna Tuna is delicious and fresh, and has always been one of the most popular seafood dishes in Japan and Taiwan Province Province, especially tuna sashimi, which is the best among sashimi. Not only the old diners get the taste, but even people who eat less sashimi will choose tuna sashimi to enjoy. From the species of tuna, the quality of sashimi is bluefin tuna, Ma Su tuna, bigeye tuna and yellowfin tuna from high to low. Bluefin tuna and Ma Su tuna have low production and high prices. Common tuna slices are bigeye tuna and yellowfin tuna. Raw food is the best, and cooked food is fragrant and delicious. Canned tuna in oil is very delicious. Not only Southeast Asians love it, but Europeans and Americans also use it to make sandwiches. Deeply loved by consumers, the market is very broad. Japan, western Europe and the United States are the three major markets for tuna products. It can be said that tuna is a household name in these countries, just as our people are familiar with large yellow croaker, small yellow croaker and hairtail. In some countries in Europe and America, people compare tuna meat to "sea chicken" or "veal". American-made canned tuna in oil is popular all over the world and is one of the best-selling foods in the world. There is a great demand for tuna in Japan, with an annual consumption of 800,000-900,000 tons, accounting for about one-third of the world demand, especially fresh tuna, accounting for 60% of the demand, and the annual import volume is about 65.438 billion US dollars. In today's reform and opening up, people in China are living better and better, eating more and more, and paying more and more attention to food and health care. They have lost the freshness of high-end seafood such as lobster, mussels and salmon. So now I am exploring the domestic market, and I will directly ship some tuna sold in Japan back to China for sale, so that China people can enjoy this delicious and nutritious treasure in the sea at any time. Tuna sashimi related dishes Tuna seems to be very common in western or Japanese cuisine, and the method of eating it raw is classic. Chinese food is also available, but it is less. Let me introduce it to you. Tuna Sushi Tuna Sashimi Two Miso Tuna Steak Crispy Tuna Steak Sweet and Sour Tuna Ball Soy Sauce Swallow Fried Lettuce Olive Roasted Tuna Oatmeal Tuna Porridge Asparagus Tuna Salad Brandy Tuna Salad Seafood Sashimi Tuna Chowder Stir-fried Braised Tuna: Ingredients:.
Method: Cut tuna into strips, mix with wine and soy sauce, and then mix with starch. Remove celery tendons, cut into 4cm long, cut several holes longitudinally with a knife, and mix in the roasted gravy. Then fry tuna, celery and scallion in oil until brown, and pour gravy while it is hot.
Efficacy: Treating dizziness. Japanese tuna tomato sauce mixed salad Korean tuna egg tuna sushi tuna rice salad contains: energy-189 kcal vitamin B6-0.5 1 mg protein-27000g. 50mg thiamine-0.02mg riboflavin-0.12mg nicotinic acid-16. It is especially suitable for patients with cardiovascular and cerebrovascular diseases and has a certain effect on children's growth and bone health. The ratio of DHA and EPA in tuna oil is 5: 1, with high DHA content and low EPA content, which is suitable for children and adolescents. Reason: Because EPA has the function of lowering blood pressure and blood lipid, children and adolescents with normal blood pressure and blood lipid are not suitable for using healthy food with high EPA content. However, because modern teenagers eat too much meat and often eat high-fat foods (fried chicken and other foreign fast food), a small amount of EPA can help prevent its adverse effects, enhance memory and improve language ability. Precautions are not suitable for pregnant women. Tuna is not within the fasting range of pregnant women because it contains less mercury. However, some people in charge of making mercury regulations believe that it is not good for women to eat a lot of canned tuna during pregnancy. In some areas, pregnant women are restricted to eat no more than 65,438+0.98 grams of tuna per week. After mercury enters pregnant women, it will destroy the central nervous system of the fetus, resulting in low cognitive ability of infants. Some people think that about 60 thousand children are affected by mercury every year. Japan auctioned $6.5438+0.8 million, making it the most expensive tuna in history. Pollution caused by industrial waste leads to an increase in the incidence of methylmercury-related diseases, including stunting of children. This makes tuna (whether tuna steak or canned tuna) disappear from the menu. But some pathogens, such as mackerel toxin produced by improper handling of fresh fish, still infect people every year. Symptoms range from headache to diarrhea and even blindness. The safest way is to freeze the fish, or eat it only in reputable restaurants. "Capture Case 2065438+2005 65438+ 10, a 5 6-year-old female fisherman Donna Pascoe captured a Pacific bluefin tuna weighing 823 kilograms. This record-breaking tuna is twice as big as a baby elephant. Donna is now waiting for the certification of the International Fishing Association to announce that she has broken the world record. After 4 hours 1 1 minute of fighting, the tuna was finally towed to the ship by the anchor machine. This tuna can be canned into 3 162 fish. Bluefin tuna is the largest tuna in the world, and they can survive for more than 40 years. 2016 65438+124 October, a tuna weighing 4 17kg was caught in Wakayama Prefecture, Japan, which was the largest tuna caught since 1949. This tuna was finally auctioned at a price of about 1 1, 000 RMB. It is reported that if it is made into tuna sashimi, this fish is enough for 3000 people. 20 1910.5, 19, a bluefin tuna weighing 278kg was sold for 333 million yen, setting a historical record.