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Species invasion has always been a problem of trouble in many countries, and alien species are usually tenacious, multiplying rapidly in the absence of natural enemies, very easy to flood, and destroying the balance of the local ecological environment.
With the development of means of transport and the increasingly close exchange between countries, the invasion and proliferation of alien species has occurred repeatedly, and the mainland is no exception.
Tilapia, largemouth bass, bearded catfish, scavengers, etc. are all exotic species, but they have penetrated deep into the waters of many provinces on the mainland, and the population continues to grow and develop, and native fish compete for living space and resources.
In addition, sunfish have also been flooded in many provinces in the south of the continent, and their trend is almost beyond the previous fish flooding.
Sunfish
Northerners may be unfamiliar with sunfish, but people in southern coastal areas such as Guangdong and Fujian should have an impression.
Sunfish native to North America, is a small freshwater fish in the middle and high-end, very small, generally only a few two weights, the largest is only two or three pounds, the price is about 20 yuan / catty.
It is known as "Chang'e in the water", looks very similar to tilapia, the head is small and the back is high, and the hind edge of the gill cover has a black ear-like soft membrane, which is the most important feature of judging the sunfish;
Sunfish are omnivorous animals, mainly feeding on zooplankton, aquatic insects and aquatic plants, and also like to eat small trash fish and small molluscs;
Its adaptability is very strong, it can live normally at a water temperature of 1-38 ° C, and it can reproduce on its own, and its survivability is stronger than that of many fish.
Sunfish are flooded in many provinces in the southern part of the continent
In an open reservoir in Dongguan, Guangdong Province, an angler harvested more than 100 sunfish in just half a day, which is completely different from other fish such as crucian carp and tilapia that he caught before, which shows that the number of sunfish has far exceeded that of other fish.
Sichuan Shengzhong Lake Reservoir is a very famous large reservoir in the mainland, and an angler caught nearly 30 sunfish in only half an hour, an average of one per minute.
These fish are fat and rounded, and the number of sunfish in the reservoir can be imagined.
In addition, traces of sunfish have been found in the rest of Sichuan's reservoirs, and the population has increased almost explosively.
The same phenomenon also appears in Guizhou, Guangdong, Guangxi and Fujian and other places, Jiangxi, Anhui and Hubei have not been spared, even the mainland is famous for its excellent water quality of Qiandao Lake is also doomed, many fishing friends in Qiandao Lake have said that they have caught different numbers of sunfish.
As the sunfish become more and more widespread, flooding has become a trend, and its harm is also worrying, because its reproductive ability is too terrible!
How terrible is the reproductive capacity of sunfish in the ecological disaster caused by Japan?
In the 1960s, Crown Prince Akihito visited the United States, and the mayor of Chicago gave the sunfish as a gift.
Akihito was very fond of the appearance of the sunfish, believing that it had a strong ornamental nature and a good taste, and after bringing it back to Japan, it was promoted and farmed, and soon developed to 1400.
In order to expand the scale of sunfish farming, the staff threw sunfish into Lake Biwa, which was the largest lake in Japan at that time, and the growth of sunfish as an exotic species can be imagined.
Sunfish is a multiple spawning fish, the breeding cycle is from March to October of each year, a spawn can reach 10,000 ~ 60,000 pieces, the water temperature at 20 ° C can achieve multiple spawning a year, from hatching to growth only one and a half years,
Although it belongs to the warm water fish, it has a very strong cold resistance, a high degree of disease resistance, and its survivability is stronger than that of tilapia.
Due to the lack of natural enemies, coupled with abundant food supplies and wide living space, sunfish quickly expanded into other waters, flooding Japan.
In just thirty years, the living space of Japan's native fish and other aquatic species has been continuously squeezed by sunfish, the juvenile fish and fish eggs of native fish have been eaten away, the Japanese salmon has eaten into a rare species, and the native fish have almost disappeared, causing serious ecological disasters.
In response to the biological dilemma caused by the sunfish, Akihito had to apologize and the authorities had to call on the public to catch and eat the sunfish, but the effect did not seem obvious, because they were still suffering from the problem.
So, is the emergence of sunfish on the mainland related to the flooding of sunfish in Japan?
How did the sunfish enter the continent? And why is it flooding?
Among the 32 species of sunfish, the common ones on the mainland are the blue-gilled sunfish and the green sunfish, which were introduced into domestic aquaculture in 1999 as ornamental and sport fishing fishing.
The earliest appearance of sunfish in mainland China was in 1987, and after the introduction of the Fisheries Society, it was trial cultured in Beijing and Hunan, and it was successfully promoted to the southern coastal areas such as Guangdong.
Based on the advantages of the growth characteristics of sunfish, many places have farmed it as an economic fish, and the scale of sunfish has been expanding.
However, due to inadequate management, coupled with heavy rains, floods and other factors, individual sunfish have escaped from fish ponds to other waters, and continue to breed, and the number is increasing;
Moreover, in addition to eating, the sunfish is suitable for ornamentation, and many people will keep it as a pet or release it.
As a result, more and more sunfish in natural waters have appeared in large areas throughout the continent. In 2015, green sunfish were found in the Dabie Mountains of the mainland and swallowed the eggs of native fish, and sunfish also appeared in Sichuan, where no one breeds sunfish...
With the flood of sunfish, many people are also worried about native fish and other aquatic species, but some netizens said that there are few opportunities for alien species to flood on the mainland.
Although the reproductive ability of the sunfish is strong, it also has weaknesses: the meat is more thorny and less thorny, the taste is delicious, and it is too delicious to stop! Therefore, many netizens have bluntly said that there is oral.
Some experts also said that from past experience, the flooding of sunfish does not need to be alarmist, after all, the mainland is also a big country of gastronomic culture, and the experts' statement is not unreasonable.
What do you think about that?