Bluefish is one of the four famous fish in China, ranking first, with a long history of breeding. Like silver carp, bighead carp, and grass carp, bluefish also belong to the "national freshwater fish", and its important position is self-evident.
The body size of the bluefish is similar to that of grass carp, which is typical of spindle shape, but the blue fish has a dark body color, so it is also called black carp. Wild bluefish especially like to prey on snails and clams, so they are also called snails. As we all know, bluefish are mainly distributed in the bottom of the water body, along the silt of the river and lake to search for prey, rarely surfaced, the main reason is that the bottom of the water body is rich in snails.
Since the 1960s, major fishing grounds in southern China have begun to use bluefish to remove vertebral snails from fish ponds. This snail is the first host of compound flukes, which is very harmful to the health of humans and animals and fishery production, and is the object of vigorous removal. Bluefish is a natural "conch buster", a pond set a few bluefish can easily solve the hidden dangers, greatly reducing the risk of fish suffering from parasites, favored by fishermen.
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In 1960, China's older generation of aquatic experts successfully conquered the artificial breeding problem of bluefish. The aquaculture industry of bluefish began to enter a prosperous period, and artificially bred blue fish fry were widely released into natural waters, making indelible contributions to the elimination of harmful snails such as Fushou snails and vertebral snails.
In the Chinese sport fishing industry, bluefish often appear as the "grand finale giant". Among the four major fish, the bluefish is the largest. According to domestic encyclopedias, adult bluefish have a body length of more than 100 cm and a weight of more than 30 kg, and older bluefish can grow to 145 cm and weigh more than 70 kg.
According to Wikipedia, the typical length of adult bluefish is 60 to 120 cm, the maximum body length can reach 190 cm, and the weight can reach 109 kg, making it one of the largest carps in the world. Through literature and media reports, it is not difficult for us to conclude that the maximum body length of the bluefish is close to or even more than 2 meters, and the maximum weight can break through 200 pounds!
The large-scale "Blue Fish King" has been arrested and landed in lakes and reservoirs all over China, and its weight often exceeds 100 kilograms, but not many of them exceed 200 kilograms.
In October 2015, the staff of the Qiandao Lake Fishery caught a "blue fish king", with a body length of 175 cm, a bust circumference of 135 cm, and a weight of nearly 180 kg.
In September 2021, an angler caught a giant blue fish weighing about 200 kilograms in the Fuchun River, but unfortunately it was slaughtered on the spot after landing, just to remove the blue fish stone.
In the summer of 2021, Wuhan Mulan Lake officially opened for fishing, and the fishing season lasted for 3 months. During this period, a giant bluefish was caught by fishermen, and its measured body length reached 150 cm and weighed more than 140 pounds.
The most shocking thing is the "Blue Fish King" in Nanjing, which weighs 212 pounds, and it is said that a large mouth can stuff four fists! This big fish is the best of the "Blue Fish King" in China, the volume is twice that of the ordinary Fish King, and it took 6 hours for 12 fishermen to subdue it.
Blue fish is regarded as a treasure in the folk, and the larger the individual, the rarer it is, and the blue fish stone taken from the throat is full of mystery and valuable. According to the survey, the current 1 gram of blue fish stone on the market can be sold for about 25 to 40 yuan, and the larger the specification, the more valuable it is.
Blue fish stone is also called fish essence stone (there is also a "fish shock stone"), fish pillow stone, its value is mainly derived from folk speculation. From an anatomical point of view, the bluefish stone is actually a keratinous hyperplasia formed under the occipital bone of the bluefish, which is specially used to crush the hard shell of the snail and facilitate the absorption of soft and tender snail meat.
Scientific studies have shown that the size of the bluefish stone and the size of the bluefish have a certain relationship. In general, the larger the bluefish, the more prominent the hyperplasia, and the larger the bluefish stone removed.
When the body length of the bluefish is less than 15 cm, the pharyngeal teeth are not developed enough to crush the hard shell of snails, and the bluefish mainly feeds on large right-angled, copepods and other zooplankton during this period.
As the body of the bluefish grows longer and the hardness of the pharynx becomes larger, some smaller snails and clams can be crushed, but the more hard snails are still out of the predation range.
As an adult, the pharyngeal teeth of the bluefish are further hardened, the crushing ability is significantly enhanced, and it can easily crush large snail shells, and almost all snails that can swallow the mouth are on the prey list.
It should be noted that when the bluefish grows to 5 to 10 kilograms, it has already produced bluefish stones, but the specifications are only about 2 centimeters, and the economic value is not large. A hundred pounds of blue fish, the removed blue cloud stone can be left over 30 to 50 grams after processing, and the value is higher.
From the appearance, the blue fish stone is warm as jade, and the color is yellow. After drying, the texture becomes hard, crystal clear, the texture is comparable to jade, and it is a rare item. Folk people of the older generation have said that the polished blue fish stone is made into a pendant and tied to the wrist of a child, which can play an effect of exorcising evil spirits and blessings.
In the ranking of the four major fish, the name of the bluefish ranks first, but the actual status is very embarrassing. In China, there are not many people who cultivate bluefish, and its production is also in the position of "crane tail" among domestic fish.
According to the 2018-2019 Fishery Statistics Yearbook, the actual production of bluefish is less than 700,000 tons, far lower than the 5.5 million tons of grass carp, 3.8 million tons of silver carp and 3 million tons of bighead carp. Even more surprising is the production of exotic tilapia even reaching 1.6 million tonnes, more than twice the production of bluefish.
Because of this, many people think that although the blue fish has the name of a family fish, its strength and status do not match, and the situation is very embarrassing. In terms of aquaculture, the appearance rate of bluefish in natural waters is also very low, and some small trash fish and exotic fish species have begun to "take the upper position".
Some people may refute it: the bluefish is huge, the natural spawn volume can reach 500,000 to 1 million, the reproductive ability is strong, and it is reasonable to say that it should not fall to the point of being "overtaken" by foreign fish. But the facts are in front of us, which makes people reflect on what is wrong.
The reason why bluefish are not welcomed by farmers and the number of them in the wild is very much related to the following two factors:
Feeding habits
Bluefish feed on snails, which are not primary producers in nature and are already limited in number. According to the principle of energy flow, each level of nutrition is increased, and the energy will be reduced by 90%. Diet determines that bluefish will inevitably be greatly restricted when obtaining food, and the restrictions of grass carp and silver carp are much smaller, and the latter has sufficient food resources and is more likely to have explosive proliferation.
For example, among the Asian carp that flooded the United States, bluefish are rare, but silver carp and grass carp are all over rivers and lakes, constantly expanding, causing Americans a headache. At the end of the day, the source of bait for bluefish is limited. On the side of farmers, it is difficult to find sufficient snail bait when raising bluefish, which is expensive and difficult to breed, resulting in many people being reluctant to raise them.
The breeding cycle is long and the sexual maturity is late
The first appeal of farmers is, of course, to make money, and the shorter the return time of funds, the better. However, the rearing cycle of bluefish is particularly long, it takes 4 to 5 years to mature in the south, and 6 to 7 years in the lower temperature of the north, which is too high in time cost, which makes many farmers prohibitive.
Under natural conditions, there is less natural food, slow development, and the breeding interval between adults is very long. Compared with several other domestic fish, the gonads of bluefish develop later, and artificial induction is more difficult, which has led to the inability of large-scale promotion of bluefish. Speaking of which, it makes sense that the production of bluefish is lost to exotic tilapia (which can be bred in 3 months).
Bluefish is one of the four famous fish in China, with a maximum body length of up to 2 meters and an extreme weight of more than 100 kilograms. According to experience, the larger the size of the bluefish, the larger the blue fish stone taken out, the better the texture, and the higher the price. However, the price of blue fish stone is mainly caused by speculation, and the practical value is not high.
In recent years, the number of bluefish in the wild has become more and more rare, and the production has been tepid, and the status of bluefish has been questioned. However, bluefish have an irreplaceable role in the sport fishing industry and the control of disease snails, and will not be eliminated in the future. On the contrary, China also needs to increase the release of bluefish, which is of great significance for solving the hidden dangers of the vertebral snail in the Yangtze River Basin and improving the ecological environment.