│Yang Yexin│
Assistant researcher at the Pearl River Fisheries Research Institute of China Academy of Fisheries Sciences, the research direction is the invasion mechanism and prevention and control technology of alien aquatic animals. The main work is to explore the ecological adaptation mechanism of invasion of alien aquatic animals from the molecular level, and provide theoretical reference for monitoring, early warning and prevention of invasive species.
The scientific name of the Brazilian turtle is the Red-Eared Colorful Tortoise (Trachemys scripta elegans), which belongs to the Reptilia, Testudoformes, Emydidae, and Trachemys. It is commonly known as the Brazilian turtle, Red-Eared Turtle , Brazilian turtle, etc. It is native to the southern United States and Mexico. Since its introduction to mainland China in the 1980s, it has spread to Hainan, Jiangsu, Hunan, Shanghai, Beijing and other places in my country for more than 30 years.
Because the Brazilian turtle is cute, has strong vitality and is cheap, it has become a favorite pet and quickly occupy an important position in the flower, bird, fish and insect market. However, in the long-term development process, Brazilian turtles have grown wantonly in my country's ecological environment due to their own characteristics and reasons such as "pet abandonment", "breeding and escape", and "religious release", and have become a veritable "ecological killer". They can be seen from temples, release ponds and artificial ponds in parks to streams, rivers, and reservoirs in the wild. Recently, the reporter learned about the invasion of Brazilian turtle and prevention suggestions from Yang Yexin, assistant researcher at the Pearl River Fisheries Research Institute of the Chinese Academy of Fisheries Sciences.
There are Brazilian turtle breeding farms in many provinces across the country
Brazilian turtle is native to the central United States to northern Mexico, and was introduced into my country as an ornamental turtle in the 1980s.
According to relevant information, although the Brazilian turtle looks honest and honest, its cruelty is intimidating. In the Mississippi and Grand River basins in North America, they were originally quite low-key and maintained a balance of quantity. The wild natural enemies of many Brazilian turtles, such as egrets and raccoons, have basically maintained the number of Brazilian turtles by hunting turtles eggs and young turtles for food. However, if the Brazilian turtle, which leaves the native environment and lacks the balance between natural enemies, will become a flood and an ecological disaster in the new environment. As an ornamental pet, Brazilian turtles are breeded in most provinces (autonomous regions, municipalities) in my country. Currently, Brazilian turtle breeding farms are distributed in 17 provinces and cities including Hebei, Henan, Shaanxi, Liaoning, Sichuan, Hubei, Hunan, Jiangxi, Anhui, Shandong, Jiangsu, Zhejiang, Fujian, Hainan, Guangdong, Guangxi, and Shanghai.
Brazilian turtle invasion and spreading hazards
"Brazilian turtle has a wide range of recipes, strong adaptability, and is prone to invasion and spreading. It is listed by IUCN (Island Conservation Union) as one of the 100 most destructive invasive organisms." Yang Yexin said that the biological characteristics of Brazilian turtle determine that it has excellent adaptability in most parts of our country. Although Brazilian turtles are freshwater organisms, they can also survive in a saltwater environment. The appropriate temperature for Brazilian turtles is 20~34℃, and the optimal temperature is 32℃. When the temperature drops below 14℃, stop feeding and falls below 11℃ and enter hibernation.
In addition, Brazilian turtles are omnivorous and are more hungry resistant. They like to eat meat and vegetable leaves, and have strong predation ability. Loaches, shrimps, frogs, fish, aquatic insects, snakes, aquatic plants, bird eggs, and chicks can all become food for Brazilian turtles. This not only poses a threat to the diversity of local biological species, but is not conducive to the survival and development of local turtles.
At the same time, Brazilian turtles not only have a long lifespan (about 20-50 years), but also have strong reproductive ability. Generally speaking, the age of sexual maturity is generally between 4 and 5 years old, and May to September is the breeding period. You can lay eggs 3 to 4 times in one year, and each time you lay 3 to 19 eggs. Secondly, the phenomenon of turtle hybridization is very common, including turtle species with distant kinship, giving birth to "mixed-race children". For example, hybrid individuals of Brazilian turtle, Chinese turtle and strip-necked turtle can be seen in the flower, bird and fish market. These "mixed-blood children" often lose their ability to reproduce and lead to changes in the genetic structure of native turtles. "In addition, Brazilian turtles that spread to the wild will plunder the survival resources of other organisms and exclude and squeeze the living space of local turtles."
Therefore, when Brazilian turtles are released in large quantities or escaped into the natural environment, it will bring serious threats and damage to the local biological resources and ecological environment.For example, the Keelung River in Taiwan Province was affected by the Brazilian turtle, and its ecosystem was severely damaged, and the local turtle species were no longer visible.
"In addition, Brazilian turtle is also an important transmission medium for Salmonella." It is reported that in young turtle breeding, more than 85% of Brazilian turtle carry Salmonella and spread to constant temperature animals through feces, water sources, etc., which has an impact on human health and life safety. According to relevant surveys, 14% of Salmonella infection patients in the United States are from turtle infection.
At present, in addition to the natural spread of Brazilian turtles after establishing populations in the wild natural environment, artificial introduction and breeding is also an important way for Brazilian turtles to spread, because escape and discarding may occur during the breeding process. "This part includes discarding the breeding enthusiasts at will after breeding for a period of time, and discarding some groups with poor breeding quality or slow growth in the farm. " Furthermore, artificial release is also an important way for the spread of Brazilian turtles, because Brazilian turtles are very cheap, so they become objects of release and are released to temples, rivers, lakes, etc. This situation has been particularly prominent in recent years.
Yang Yexin pointed out that the biological characteristics of Brazilian turtles determine the simplicity and convenience of breeding and management of Brazilian turtles. People have common behaviors of abandonment in the process of raising pets. In addition, Brazilian turtles are a common animal in religious release. Many people lack ecological awareness and have low awareness of the harm of Brazilian turtles, so they release large amounts of them into the wild, thus bringing ecological risks to the local natural environment.
Scholars such as Gong Shiping and Yang Jiangbo in "Research on the Distribution Status and Diffusion Path of Alien Species Red-Eared Turtles in China" explained that Brazilian turtles are currently distributed in the wild in more than 30 provincial administrative regions in my country. Among them, the Pearl River water system and the Yangtze River water system are relatively large, especially in some densely populated areas, tourist scenic spots, forest parks and other places. The distribution probability is relatively high, and human factors are obvious.
needs to strengthen management and publicity
Compared with some countries, China's laws, regulations and systems on Brazilian turtle trade, breeding management, etc. are still incomplete. Brazilian turtle continues to enter the country through various channels and continues to expand in various parts of the country, which makes it more difficult to manage Brazilian turtle. In this regard, Yang Yexin suggested that management and publicity should be strengthened, public awareness should be raised, and popular science should be used to help the public establish a correct awareness and prevention awareness, and not release it in the wild at will.
However, improving people's awareness requires a long process and it is difficult to achieve immediate results. Therefore, legislation is needed. Relevant departments need to formulate corresponding laws and regulations based on my country's actual situation; relevant management departments should also make daily management plans, such as focusing on controlling areas with frequent release holidays and release activities, and guiding and regulating people's release behavior.
As a scientific research institution, scientific means and methods need to be used to reduce the damage and impact of Brazilian turtles on the regional ecological environment, such as strengthening the field distribution survey of Brazilian turtles and other invasive alien species, and comprehensive prediction and evaluation of the invasion risk of Brazilian turtles, etc., in order to provide an information basis for related work. Because Yang Yexin's main work is to study the ecological adaptation mechanism of invasion of alien aquatic organisms from the molecular level, she hopes to deepen research in this area in the future to provide more basic data and theoretical references for the monitoring, early warning and prevention of invasive species. (Source: Ocean and Fisheries Magazine Luo Yin)
