1. The scavengers in Guangdong are flooding, and the situation is not optimistic. The crucian carp, white stripes, and warped mouths in individual rivers and ponds were gradually eaten away by scavengers, so that the huge water surface was full of scavengers rampage inside.
Scavengers are native to Latin America and were introduced to China in the 1990s as an ornamental fish. The strange appearance is on the one hand, more importantly, the scavenger can swallow the algae floats, diatoms, organic detritus of pellet feed in the fish tank, and the ability to purify the water quality is excellent, so because of the "super ability" of cleaning water quality and taking care of the fish box, the scavenger is famous in the aquarium circle, and soon became the pet in the fish tank and fish box.
But the scavenger grows rapidly, the size is large, and the objects of feeding become diverse, like some sick and injured small fish becoming its new target. The small fish are often inflamed in the injured area, secreting a strong taste of mucus, which is very popular with the scavengers, so they often take advantage of the night to swallow the small fish, which naturally makes the owner angry. Some people are discarded in ditches and rivers. Since then, the scavenger has begun its journey to become king and hegemon.
The scavenger is grayish-black, with white patterns on its back and sides, and has an ugly appearance; it has less flesh but hard bones. During the predation, the scavenger's fin spines expand and erect, making a defensive and resisting posture, and even rushing out of the impact. Birds that fly in the air and catch fish by burrowing into the water at high speed are often defeated by scavengers: either the shell is too hard for the beak to be pecked at; or the bone is punctured or stuck in the throat during swallowing.
Scavengers are imported products, and its natural enemies have long evolved in the rivers of Latin America, such as sub-pufferfish and American crocodiles that eat several scavengers at a time. The main opponent is also the otter, the adult otter is more than twenty kilograms, but can eat 4 kilograms of scavengers in a day. So the number of scavengers in the Amazon has not increased significantly, or even shrunk slightly.
2. However, the rivers and lakes in Guangzhou and Guangxi are different, and the original fish and other creatures active at the water's edge have no means of "hunting" scavengers. On the contrary, the scavenger grows and multiplies freely, and almost all freshwater fish like ears of wheat, white stripes, crouching tigers, and cocked mouths have become its mouth. Food is abundant, the water temperature is suitable, and in addition to eating wildly without restraint, spawning and reproduction has become its main task. To maturity, scavenger seedlings generally take about 2 years, and sometimes the gonads can develop in one year.
Every year from March to June is the peak of mating, when groups of scavengers gather like the two sides of the river, in the water surface and the shore soil contact place constantly holes, mating, the river on both sides of the fence, berm increasingly loose, rarely accidentally cause collapse, serious time the reservoir flood control, flood discharge ability is affected. The Hydraulic Exploration Research Institute has studied this, pointing out that the two sides of the river channel visited by scavengers can be up to 4 meters of soil per year.
From September to January of the following year, the scavenger spawning period can produce about 900 fish eggs at a time, but the scavenger spawns more than once during this period, so after a full-year cycle, the number of scavengers increases rapidly. At the seedling stage, scavengers often accompany them, and there are few natural enemy attacks, so the scavenger seedlings that are active in the waters of Liujiang, Yongjiang and Xijiang in Guangxi have a very high survival rate. Growing, mating, reproducing, and growing again, the whole process is completed in one go, which is why the scavengers quickly dominate the rivers.
At present, China's Sichuan, Chongqing, Jiangxi, Hainan, Anhui and other provinces have found the active figure of scavengers, but the earliest introduction of scavengers is China's Taiwan Province. After World War II, tilapia was the first exotic fish species introduced to Taiwan, and although it was also recognized by the locals, it was always difficult to get on the table, and it was called "garbage fish". Later, scavengers were introduced as a foil for ornamental fish, used to clean water tanks, and then gradually occupied the rivers in central and western Taiwan, and the name "garbage fish" became the exclusive scavenger.
3. How to clean up and eradicate the problem of scavenger flooding is a difficult problem in front of us, and the measures adopted by various countries are different. India also has cases of scavengers dominating rivers, but the measures taken by people are more "gentle and direct consumption: the method of processing scavengers is not complicated, first remove the internal organs, then clean them, and the rest of the work is either braised, boiled, or fried." But Indians can't live without curry, so they always try to add a little curry flavoring. In addition to food, Indian daily necessities are also extremely scarce, artisans found that the scavenger's leather is hard, so the scavengers were cleaned up, cut into "leather shoes" to sell, and even attracted people to rush to buy, after all, the price is really low, preferential.
The gap with India's diet is huge, our people do not like the taste of scavengers, and the methods of dealing with scavengers are more choices to directly eliminate them. The scavenger itself is a product of the tropical region, and the ability to withstand high temperatures and hunger and thirst is strong: the scavenger is exposed to the sun for two days, and then put in the water to recover as usual; it is buried in the earth pit, and it remains active for 24 hours, so incineration and permanent burial are the most commonly used methods in China.
But both methods are costly and inefficient, and can't keep up with the rate of scavenger breeding. So poisoning has always been the direction of research, but so far there has not been a successful case. Australia's long-haired rabbits are flooded, and the local chemical agents have been poisoned in large quantities, and it is true that thousands of rabbits have died out in a short period of time. But it didn't take long for the surviving rabbits to gain immunity and had to re-study the new reagents, and the end result was increased resistance in the rabbits.
Symbiosis with other organisms may be a line of thought. Blackfish and yellow spicy ding have a good resistance to scavengers, so in the rivers and lakes where scavengers flood, release some blackfish to obtain economic income, and hire more manual scavengers.
Original: Old High