The sunfish of Qiandao Lake
Sichuan, Guangdong, Guangxi, Guizhou... Many southern provinces and cities are now facing a new threat, sunfish invading .
If you are a frequent fishing enthusiast, you must understand what fish invasion means. At the same time, these invasive fishes greatly affect the fishing experience.
According to Nanchong a fishing friend said that he went to the river to fish. Half an hour later, all the fish he caught were sunfish, weighing about 30 kilograms. This was more uncomfortable than the "air force".
What is surprising is that the protagonist this time is not tilapia , not Egyptian leatherback catfish, nor scavenger .
Sunfish appearance
The sunfish may not be as famous as other invasive fish , but now the problem cannot be ignored.
Even Qiandao Lake cannot escape the bad luck. Sunfish can also be found here. As a famous national scenic spot in my country, the appearance of sunfish has made many people start to think about the invasive alien fish species in China. how many?
The beautiful scenery of Qiandao Lake
I need to briefly add some knowledge about sunfish. The mouth of adult sunfish is dark with mottled brown, and the belly is usually golden.
There is a bright orange spot on the dorsal fin of the male fish , and there are 3 to 5 radial reddish-brown stripes around the eyes. The bright and bright appearance of
reminds people of the brilliance of the sun, so it got its name.
The appearance of adult sunfish
Sunfish is native to America, and is mainly distributed in the southern part of the Mississippi River basin.
They can be found from the Gulf and Atlantic coasts northward to the Chesapeake Bay and even in the other Great Lakes regions of the United States.
The habits of sunfish are as restless as their colors, and they are extremely aggressive and they are also very cold-resistant.
Even in stagnant streams, you will occasionally find one or two sunfish.
Generally speaking, it is difficult for most fish to survive in a low-oxygen environment, but sunfish can, which shows that they have excellent survival and reproductive capabilities.
Various sunfish under the family Sunfish
Sunfish Ecological behavior is relatively simple. Their main diet consists of small insects, lobsters and other fish.
Similar to most fish, sunfish mainly rely on their own vision to hunt prey.
Every year in May, is the time when sunfish start breeding . At this time, sunfish will choose to build their nests into rocks or gravel piles.
The entire appearance of sunfish will also change during the breeding season. For example, the male's eyes will turn red. After the
female completes spawning, the subsequent raising tasks will be handed over to the male fish until the eggs are fully hatched into fry .
Sunfish characteristics and region of origin
In addition, Sunfish are extremely adaptable and can be seen even in river systems in the Rocky Mountains .
However, in comparison, they prefer waters with a gentler flow rate and places where the water body is relatively nutrient-rich.
So in our country, how did the sunfish come across the ocean and eventually become a widespread fish species?
Comparison of Male and Female Sunfish
Invasion Crisis
In fact, like most fish species, my country introduced a large number of exotic fish species from the 0s to the 1980s to improve the economic capacity of the fishery breeding market.
and Sunfish was introduced to inland areas for breeding in 1987. The delicious meat of sunfish also quickly became the new favorite of the catering industry.
At that time, when sunfish had not been cultivated on a large scale, due to its good use value, it was once compared with and bass , and it was a mid-to-high-end fish.
Later, sunfish received good market feedback, so it was cultured in many southern provinces and cities such as Guangdong, Fujian, and Zhejiang.
Fish ponds for fishery breeding
Nowadays, sunfish appear in Qiandao Lake, and seeing signs of flooding makes people worried.
Based on the investigation of the water quality resources and fish community structure of Qiandao Lake, relevant domestic researchers have previously conducted an investigation of Qiandao Lake.
from 016 to 2017 During the year, researchers conducted a large number of surveys on fish in the Qiandao Lake area.
Preliminary investigation of the fish community structure shows that Cyprinidae fish species are the most numerous, mostly pelagic, omnivorous and lake-dwelling fish.
The main fish species of carps
Related investigations finally collected 528 fish. In addition to the main fish just introduced, there are also omnivorous fish and carnivorous fish .
From the analysis of the fish habitat water layer in the reserve, the distribution of fish in the upper middle layer and the lower middle layer is quite different, there are very few migratory fish.
Related research mainly focuses on several aspects such as fish community species composition, advantages and community biodiversity analysis.
The survey shows that the exotic fish species in Qiandao Lake have a certain impact on the fish community structure , and the fish that has a more obvious impact is the bluegill sunfish.
ABC curve of fish community in the water area of the survey area
As for how the sunfish in Qiandao Lake got here, the researchers believe that these fish groups should be cage-cultured fish that escaped to the local waters due to human or natural factors. in the ecosystem.
Regarding biodiversity and fish community structure, extremely aggressive and highly fecund fish like sunfish are likely to become invasive species .
The reproductive capacity of sunfish may not be as abnormal as that of tilapia, but it is still among the best among fish.
Sunfish that can be easily caught
As long as the water temperature is suitable and the hatching location is suitable, the sunfish that meets the reproductive conditions can reproduce three times a year and can spawn up to 0,000 eggs each time. After the
fish eggs hatch, the fry only need and a half years to complete sexual maturity and then reproduce more sunfish.
Curbing the development of fish stocks
Many people are worried that sunfish will become a new invasive species. Many data show that sunfish have this ability.
In addition, in Japan in the last century, due to improper management of sunfish after their introduction, the sunfish that escaped into the wild multiplied rapidly.
After entering the 1st century , the problem of Japanese sunfish invasion has become very serious. The living space of the originally small number of Japanese native fish has been squeezed, and many Japanese unique fish have become endangered species.
In addition to artificially cultured sunfish , sunfish are found in reservoirs in Sichuan and many cities in the south.
If you consider the possibility of organisms invading , sunfish actually has high potential.
Important or dominant species in the waters within the survey area
Also in the fish community survey of Qiandao Lake, researchers found that sunfish have the behavior of preying on the eggs of other fish, which is obviously a threat to other fish groups. A greater threat.
However, sunfish are not migratory fish, which means that they will become sedentary fish in their long-term lives.
If there are no interfering factors, sunfish usually do not leave the water where they live too far.
But now, with the rising market popularity, sunfish has become the choice of many ornamental fish players .
In addition, while dealing with some sunfish, many sunfish were released by errors, which further harmed the original aquatic system.
The movement of ornamental fish is also a major problem.
However, relevant experts say that it takes a certain amount of luck and natural factors for an alien species to become an extremely invasive creature.
For now, sunfish has not formed a large fish school . If it wants to become a dominant population and invade other fish species, it is too early to talk about invasion.
If it were the hometown of Sunfish, they wouldn't even be able to make a splash. The fundamental reason why
invasive species have become a scourge is that they break away from the original food chain . Due to the lack of prey links in the new environment, will eventually allow organisms to overrun.
Invasive fish usually gain more advantages.
The native environment of sunfish will face predation by other large fish, turtles, snakes, alligators and birds. Numerous natural production links ensure that sunfish will not overflow. Case.
But we still cannot take it lightly . Faced with the growth of sunfish, we can see that there will definitely be regional sunfish with population advantages in the future.
In the past, due to various reasons, we have caused the proliferation of tilapia, scavenger, leatherback catfish, , and also introduced other invasive fish species.
Good fishery management can reduce the probability of invasion
When faced with the flooding of sunfish, eating is often not the final solution to the problem.
At least we can control them before they overflow. The test Qiandao Lake will face in the future may become more severe.
Therefore, it is necessary to strengthen the monitoring of alien species such as sunfish, so as to ultimately curb the harm of invasive species.
