What revelations did the extinction of the Yangtze River white slugs bring?

On the second and third days of the New Year, the news of the “white slug extinction” hung high on the hot search list, with hundreds of millions of readers, which is a good idea of the attention paid to it. But for experts, such attention is a bit late. The white slug is one of the very few ancient fish that survived the Cretaceous period from the Mesozoic Cretaceous 150 million years ago, and its distribution is extremely narrow, and is only available in China in the world, also known as the “Changjiang White Quail”.

What revelations did the extinction of the Yangtze River white slugs bring?

King of Freshwater Fish in China

Mainly concentrated in the Yangtze River basin, known as “living fossils in the Yangtze River”, highly academic research value, is China’s first-level protection of wild animals. White dragonfly kiss length up to half of the body, also known as “like fish”, is the freshwater fish family of the first “giant”, the body length of up to 7 meters, weight up to 700 kilograms, its life expectancy is generally about 30 years.

The white dragonfly has a distinct characteristic: the head length, accounting for 1/3 of the body length, small individuals about 1/2 of the body length, cloth has a plum-shaped sensor – trap. The kiss was extended, sword-shaped, and its belly mask was short and short. The eyes are very small. Large mouth, lower position, arc shape, upper and lower jaws are with fine teeth. The hole is large, and the tip of the back edge of the membrane. The body watch is smooth and scaly. Perched on the lower middle and lower layers of rivers, sometimes entering large lakes. The white dragonfly is the only large ancient fish in the Yangtze River, which can grow up to more than two or three meters in length, because of the deterioration of the ecological environment, the distribution area of the white slug gradually narrowed, the number decreased year by year, and the individual became smaller and smaller. White slugs are typical carnivorous fish, and food includes fish, shrimp and crab.

Sichuan fishermen have the “jack, one thousand pounds” of the statement. “Image” refers to the Yangtze River white dragonfly, it is said that it can grow to tens of thousands of pounds. The white dragonfly is large and fast,” known as the “Tiger in the Water” and “King of Freshwater Fish in China”, and it is also one of the ten largest freshwater fish in the world.

In addition to the white slugs, 140 other species of fish were not found in the latest survey, although the two surveys were separated by 41 years. Most of them are endangered.

The white porpoise and the Yangtze River herring were declared functionally extinct in the wild, and the white herring was declared extinct.

The IUCN IUCN official microblog announced at 12:31 on January 3 that the IUCN had not officially announced the extinction of the white slug. In this regard, the Chinese Academy of Aquatic Sciences Changjiang Institute of Aquatic Research, chief scientist, researcher Dr. Wu Qiwei 3 afternoon reply to reporters said, “there is no official announcement, but the assessment has been completed.” Publication or not does not affect its scientific conclusions. According to the official website of the Yangtze River Fisheries Research Institute of the Chinese Academy of Aquatic Sciences, since 1996, He has been a member of the IUCN/SSC Catfish Expert Group.

In 2007, Wang Ding, a researcher at the Institute of Aquatic Biology of the Chinese Academy of Sciences, wrote an article reflecting on why the white porpoise had become extinct, noting that the habitat was broken or even lost, such as food scarcity and human explosions.

What kind of reflection can the extinction of the white slug bring to people?

The research paper, published online December 23, 2019 in the international academic journal Whole Environmental Science, offers some insights.

In this paper, habitat fragmentation, degradation, spawning migration and other factors are re-promoted.

The development of the Yangtze River and dam construction in the 1970s further reduced the number of individuals in the white slugs, the researchers wrote in the paper. As a large carnivorous fish and top predator in fresh water, the population of the Yangtze River white stork may never have increased. Overfishing may have exacerbated its extinction. The degradation of habitat environment is also one of the key reasons for the extinction of the Yangtze River white stork.

The paper’s correspondent is dr. David Zhang, and the first author of the paper is Dr. Zhang Hui.

The paper says the extinction of the Yangtze River’s white slugs is the result of multiple threats, and that the protection of endangered species in the Yangtze River basin is urgently needed to avoid more similar extinction events.

The paper says there are many lessons to be learned from the extinction of the Yangtze River white stork. The paper mentions three of them.

First, studies have shown that the key point in saving the Yangtze River’s white slugs was before 1993 (i.e., before its functional extinction) and by 2005 (i.e. the expected extinction time). But all the substantive relief efforts, such as aquatic exploration, experimental capture surveys at its historic spawning grounds, and research on artificial reproductive technology, were carried out after 2006 and “it is too late to stop their extinction”. For some species, the window for protection opportunities may have closed. But for other “one-on-one” species that still have individuals to live with, it’s important to seize the remaining opportunities. The researchers believe that the risk of extinction of all endangered species in the Yangtze River should be assessed as soon as possible to determine their conservation measures and priorities to avoid a possible further extinction event.

Second, the urgency of prioritizing the protection of the species most at risk of extinction is so urgent. Conservation should focus on species that have not been seen for many years or have lost their habitat sourly and populations are rapidly declining. For example, Luciobrama macrocephalus and Onychostoma angustistomata have not been seen for many years, but have never even been evaluated in the IUCN Red Species List. In addition, some species, such as satoma, round-mouthed copper fish, Sichuan Zhero salmon, Chinese slugs, Yangtze River slugs, etc., although assessed, but has not seen natural reproduction for many years.

Third, new comprehensive surveys of the entire Yangtze River basin need to be conducted on a regular basis, for example, every five years. According to the paper, the Yangtze River basin conducted the first comprehensive scientific survey in 1973-1975, and the second comprehensive survey in 2017-2018, 41 years later. Due to a lack of ongoing records, it is not possible to determine the fate of the 140 “disappeared” species in the second survey, such as whether they have become extinct. As a result, effective interventions cannot be taken in a timely manner.

On January 3, a doctoral student at the Yangtze River Fisheries Research Institute of the China Academy of Aquatic Sciences told reporters that the ultimate significance of protecting a species is to preserve its habitat and preserve its complete natural ecology and its creatures.

The doctoral student said that if a species wants to survive, it needs food, shelter, spawning grounds, and live, and there are living individuals who can grow up, mature, have the ability to reproduce, and maintain certain populations. In the context of conservation, the purpose of any release of wild animals is population reconstruction. But the premise of release is to live in the wild.

The sightings of the Yangtze River’s white dragonflies were the most in 1985.

The long-nosed Yangtze River white dragonfly has five brothers. But four of them, people have only seen in fossils. The remaining two species, except the Yangtze River white dragonfly, its only surviving brother is living in the Mississippi River, the United States, the smaller size of the American spoon kiss. Their long noses are called spoon kisses, like spoons.

According to the aforementioned paper, between 1981 and 2003, people saw the Yangtze River white dragonfly 210 times, only 45 times made a detailed record: body length, witness location, fish age and so on.

The vast majority of sightings of the Yangtze River’s white slugs occurred before 1995, with the most in about 1985. Although China banned the fishing of the Yangtze River’s white slugs in 1983, there have been frequent incidents of mis-arrest.

Of the more than 200 sightings of the Yangtze River, 47 occurred in the upper reaches of the river and 159 in the downstream river section, which accounted for 75.7%.

Based on the only monitoring records, the researchers believe that the white slugs that appeared in the Yangtze River during the dinosaur era became extinct as early as 2005 and 2010. “The loss of this large, iconic species, which is unique and attractive in freshwater ecosystems, is a sad and irreparable loss. They wrote in their paper.

Add a Comment

Your email address will not be published. Required fields are marked *