Endangered level: vulnerable. Wild animals under national first-class protection in China. Acipenser sinensis all appeared in the Upper Cretaceous at the end of Mesozoic, about 65.438+0.4 billion years ago. Now there are 25 species of sturgeon in the world, concentrated in the northern hemisphere. There are 9 species in China: Heilongjiang Carp and Acipenser schrenckii in Heilongjiang, Sakhalin sturgeon in Tumen River, Amur sturgeon corpuscle and Siberian sturgeon in Irtysh River in Xinjiang, smooth sturgeon in Yili River, Acipenser schrenckii and Acipenser schrenckii settled in the fresh water of the Yangtze River, and Chinese sturgeon is the southernmost sturgeon species in the world. Modern distribution in the Yangtze River, Pearl River, Minjiang River, Qiantang River, Yellow River and other coastal waters and major rivers. At present, the Yellow River and Qiantang River are extinct, and the mouth of Minjiang River can be seen occasionally. The number of Pearl River is very small, and only the Yangtze River has a large existing quantity. Recorded in southwestern Korea and western Kyushu, Japan. Acipenser sinensis has a strange shape, which is quite different from ordinary fish. The body is spindle-shaped, the head is large in the shape of the Yangtze River Delta, and the front of the eyes is flattened into a plow shape and upturned. The mouth is on the ventral side of the head, forming a transverse fissure, and the mouth can freely expand and contract. There are horny nipples on the upper and lower lips. Four beards are juxtaposed in front of the mouth. Eyes are very small. There are spray holes behind the eyes. The branchial foramen is large, and the branchial membrane is connected with the isthmus. Gill harrows are short columns, thin and sharp, with 14-28 pieces, generally about 18 pieces. The skin of young fish is smooth and scaleless, with 5 rows of large rhombic bone plates, 65,438+0 rows on the back, 2 rows on the body side and 2 rows on the ventral side. The number of bone plates on the side of the body is 24-37, and the dorsal fin is very backward, with 54-66 dorsal fin strips. The upper leaf of the tail is long and the lower leaf is short, forming a curved caudal fin. The whole body bone is cartilaginous. The structure of the intestine is very strange, with 7-8 funnel-shaped spiral valves inside. The head and back of the body are bluish gray or grayish brown, the abdomen is grayish white, and the fins are gray. All these characteristics indicate that sturgeon belongs to lower bony fish. Acipenser sinensis is a large anadromous fish, and the largest individual recorded a tail weighing about 680 kg. Acipenser sinensis usually lives on the coastal continental shelf of the East China Sea and the South China Sea, and grows and develops in the sea. Male fish grow to 9 ~ 18 years old, with a body length of 170 cm and a weight of more than 50 kg, while female fish grow to 14 ~ 26 years old, which can reach the first sexual maturity. These sexually mature Chinese sturgeons enter rivers from the ocean to breed in July and August. The spawning grounds are all in the upper reaches of the river. After the Chinese sturgeon enters the river, it must stay in the river for one year and arrive at the spawning ground in June 5438+the following year 10. During this year, the Chinese sturgeon does not always swim upstream, but sometimes swims and stops, and sometimes lurks in the potholes in the river for several days. According to fishermen, when the south wind blows and the water level of the river fluctuates slightly, the sturgeon goes upstream; When the north wind blows and the water level fluctuates greatly, sturgeon lurks in the depths of the river. The ancients recorded that "fish came out of the deep waters of the river, Huaihe River, Yellow River and Liaohe River" and "its residence was also among the rocks". The Chinese sturgeon will swim back more than 3,000 kilometers in the Yangtze River, reach the lower reaches of Jinsha River and breed in the 600-kilometer-high reach of Yibin City, Sichuan Province. The breeding season is1early October to11early October. After fertilization, the sturgeon eggs are washed away by the river and attached to the stones at the bottom of the river, and the fry hatch a week later. Young fish drift down with the river, arrive at the Yangtze River estuary in July of the following summer, enter the ocean for growth and development, and then return to their birthplace to breed the next generation when they grow up. Parent fish that have laid eggs still return to the sea like young fish, and then return to the river for the next breeding trip in a few years. Sturgeon is very prolific. 1 The pregnant number of female Chinese sturgeon is 300,000-130,000, but more than 90% of the eggs are eaten by fish such as octopus and Pelteobagrus fulvidraco, and the few surviving ones fall into the crevices. However, the young Chinese sturgeon has a strong vitality. Once the young fry hatch, they will quickly float to the surface and then swim to a shallow place. They seem to know that spawning is dangerous, and only 2-3% of the total number of individuals can grow up and reproduce. Acipenser sinensis is a carnivorous fish, and the early larvae living in the middle and upper reaches of the Yangtze River feed on chironomid larvae, dragonfly larvae, mayfly larvae and plant debris. Young fish in the salty and fresh water area of the estuary feed on shrimp, crab and small fish. "Compendium of Materia Medica" records its eating habits as follows: "Eat it, open your mouth to take things, listen to it, eat without drinking, and crabs and fish eat it by mistake". In fact, the Chinese sturgeon sucks food by the expansion and contraction of the oral membrane, and most of the food objects are small animals living on the mud surface or trapped in the mud residue. The Chinese sturgeon basically does not eat during the whole migration and detention period from the ocean to the river. Therefore, the energy consumption of Chinese sturgeon in fresh water and the nutrition needed for gonadal development depend on a large amount of fat and other substances accumulated in its body before entering fresh water. Therefore, in fresh water, the closer to a mature individual, the thinner the body. Acipenser sinensis is an important large-scale economic fish. There is a proverb among fishermen in Sichuan that "a kilo of wax is like ten thousand kilos". Before the 1970s, according to incomplete statistics, the annual catch of more than 50 kilograms in the Yangtze River basin was about 400-500, and the output was between 60,000-80,000 kilograms. In recent decades, due to various factors, the number of wild individuals has decreased significantly, and it is currently in a vulnerable state. At the same time, Chinese sturgeon has certain academic and scientific value, and the China government has listed Chinese sturgeon as a national first-class wild protected animal. In the early 1980s, after the construction of Gezhouba Water Control Project on the Yangtze River, the migration route of Chinese sturgeon from the sea to the river was cut off, which seriously affected the survival of Chinese sturgeon. As early as the mid-1950s, when the planning of the Yangtze River Basin was initiated, national leaders proposed to study the impact of Gezhouba Water Control Project on fish migration and spawning grounds. At that time, a group of scientific and technical personnel and leaders of competent departments insisted on opening a hole in the dam and adding a fish passage with a width of 12m. Wu Xianwen and Cao Wenxuan, academicians of Chinese Academy of Sciences, consulted and inspected a series of compensation measures taken by sturgeon producing countries such as the former Soviet Union, Europe and America to protect and proliferate their resources based on the rich scientific data accumulated by the Institute of Aquatic Biology of Chinese Academy of Sciences in the investigation of fish resources in the Yangtze River for more than 20 years and the actual data of "fish's ability to overcome current velocity" carried out by the Institute of Aquatic Biology of University of Water Resources and Electric Power in recent years, and withstood the pressure of public opinion from all walks of life. It is resolutely put forward that "the construction of Gezhouba hub will not bring obvious influence to domestic fish spawning grounds", "Gezhouba hub has blocked the migration passage of Chinese sturgeon, which has brought serious adverse effects to this kind of fish and must be rescued" and "artificial breeding and releasing measures should be taken as the main measure, and no fish equipment should be built". "Chinese sturgeon is large in size, and the requirements for water flow conditions are very strict when going upstream. Moreover, compared with the wide river surface and the rushing river, the Chinese sturgeon can't find a fishway with a width of 12 meters. " According to the natural environmental conditions and hydrological data of the Yangtze River, it is boldly inferred that after the completion of the dam, Chinese sturgeon may form a new spawning ground under the dam for natural reproduction. This was the "Gezhouba fishway dispute" that sensationalized the whole country at that time. Academician Wu Xianwen wrote this view as a proposal and submitted it to the Central Committee, which was affirmed and adopted by the national leaders. This proposal saved the country an investment of 53 million yuan, which became a big news for scientists and democrats to participate in politics at that time. Facts have proved that the Chinese sturgeon bred in the river quickly adapted to the new environment and formed a new spawning ground in the lower reaches of Gezhouba. After the completion of Gezhouba Water Control Project, although there is a new spawning ground for Chinese sturgeon, this breeding ground has been greatly reduced, from more than 600 kilometers in the past to only 7 kilometers. With the commencement of the Three Gorges Project, once the project is completed and put into production, the water level of the Three Gorges Reservoir will be raised to175m and the discharge will be reduced by 5438+ 10/%due to the massive water storage in June. As a result, the spawning ground of Chinese sturgeon Yichang will be seriously affected, and the spawning river area will be reduced again. In order to protect 1980, a rare animal, China is speeding up the research on artificial propagation of Chinese sturgeon, releasing1-20,000 artificially propagated young sturgeons to the Yangtze River every year; Fuzhou municipal government also released 7,000 juvenile sturgeons, 5438+0,65438 to Minjiang River in February 2006. According to experts' estimation, in order to restore the resource proliferation effect of Chinese sturgeon, at least 65,438+10,000 juvenile Chinese sturgeons should be released to the Yangtze River every year, supplemented by effective protection measures, the fishing of Chinese sturgeon should be completely banned, the scientific research fish should be strictly restricted, and the spawning sturgeon population should be preserved to the maximum extent. Acipenser sinensis is a kind of fish with high protein and fat. Protein content in muscle is 16.42-20.4 1%, and fat is 3.05-4.32%. Protein content in liver is10.31-16.26%, and fat is 16.63-27.58%. The protein content in eggs is 24.90-29.70%, and the fat is 18.06-24.00. Both muscle and egg contain 17 kinds of common amino acids that can be measured. It contains 8 kinds of amino acids necessary for human body (besides colored amino acids destroyed by acid hydrolysis, there are isoleucine, leucine, lysine, methionine, phenylalanine, threonine and valine); Two semi-essential amino acids (arginine and histidine, both essential for infants); Eight nonessential amino acids (alanine, aspartic acid, cystine, glutamic acid, glycine, proline, serine, arginine). Amino acids with high content in muscle are glutamic acid, aspartic acid, lysine and leucine. The amino acids with low content are histidine, methionine and cystine. The contents of other amino acids are different. The content of essential and semi-essential amino acids in female muscle accounts for 48.54% of the amino acid content, and the egg grain accounts for 48.80%. Male muscle accounted for 49. 105. Because of its high amino acid content, delicious meat, good egg quality and rich nutrition. The edible value of muscle, fish eggs and fins of Chinese sturgeon and the medicinal value of swim bladder are the same as those of bighead carp and sturgeon. In Jiangsu and Shanghai, herring, marlin (ACIPENSER sinensis), roe (Eriocheir sinensis) and soft-shelled turtle (ACIPENSER sinensis) are listed as four famous fish.