Is the Yangtze paddlefish a mammal? There are all kinds of creatures in the world. Each animal has its own distribution area and unique living habits. Animals that people can usually come into contact with are only a few in nature. In recent years, with the expansion of human activities, some animals are facing survival crisis. Let's see if the Yangtze sturgeon is a mammal.

Is the Yangtze paddlefish a mammal 1 1. Is the Yangtze paddlefish a mammal?

The Yangtze River paddlefish is a very famous fish and a very rare species in China. From the category, the Yangtze sturgeon is an animal in the class teleost, that is, a kind of fish, and belongs to teleost from the specific classification. Mammals are a general term for a large class of animals, which refers to animals in mammals.

It can be seen that ACIPENSER Changjiang is not a mammal, because they already belong to bony fish and cannot belong to mammals at the same time. In fact, there is no intersection between mammals and fish. Any animal can only belong to one of them, and it is impossible to belong to both.

As a fish, the Yangtze sturgeon is very different from mammals. The two biggest differences are respiratory organs and reproductive methods. From the first aspect, the Yangtze River sturgeon and other fish breathe through gills. Unlike mammals, they have lungs and use them to breathe.

From the second point of view, the Yangtze sturgeon is an oviparous animal, and the Yangtze sturgeon in China usually goes to the Yangtze River when spawning; Mammals are different. They are viviparous animals. In addition, there are other subtle differences between the Yangtze sturgeon and mammals. For example, the Yangtze sturgeon is variable in temperature, while mammals are constant in temperature.

2. Is the Yangtze paddlefish a fish?

As mentioned above, the Yangtze sturgeon is not a mammal, but a fish. According to the specific classification, the Yangtze River white sturgeon belongs to the genus Acipenser, belonging to the order Acipenser, so they belong to the bony fish and also belong to the sturgeon, which is a kind of sturgeon and a more precious one among the sturgeons. As a fish, ACIPENSER Changjiang conforms to many characteristics of fish. The above gill respiration, oviposition and temperature change all belong to the same characteristics of fish.

Is the Yangtze paddlefish a mammal? 1. What is the Yangtze River paddlefish?

The white sturgeon, also known as China white sturgeon or China swordfish, is a kind of white sturgeon. Its body length is spindle-shaped, with sharp teeth on the upper and lower jaws, like kissing a sword, and its snout gradually widens from front to back. The body has no bony disk-shaped hard scales, and there is a row of spiny scales on the upper edge of the caudal fin. The back is light purple gray, and the abdomen and fins are slightly white and pink.

The paddlefish is the largest freshwater fish in China and a rare animal in China. It is a national first-class wild protected animal and is known as the "giant panda in the water". It is mainly distributed in the main tributaries of Yibin to the Yangtze River estuary in China, and also distributed in the Qiantang River and the lower reaches of the Yellow River.

Second, why did the Yangtze River paddlefish declare extinction?

For a long time, influenced by damming rivers, water pollution, overfishing, waterway regulation, dredging and quarrying, the living environment of aquatic organisms in the Yangtze River has been deteriorating, the biodiversity index has been declining, and the resources of rare and endemic species have declined in an all-round way. White formula dolphin, white sturgeon, herring, bream and other species have not been seen for many years, and Chinese sturgeon, Yangtze finless porpoise and other species are extremely endangered.

Due to environmental changes, ACIPENSER sinensis has no natural conditions for survival. Since 2003, the relevant personnel have never found the paddlefish again, and its artificial reproduction has no individual.

The above is the introduction of the Yangtze River paddlefish. ACIPENSER ACIPENSER was originally distributed in the main rivers between Haihe River and Qiantang River, but now it is mainly distributed in the Yangtze River basin and offshore waters such as the Yellow Sea, Bohai Sea and East China Sea. The sturgeon mostly inhabits the deep-water channel of the main stream, is good at swimming, and often swims in the vast water layer of the Yangtze River; Young fish often go to tributaries, harbors and even the brackish water area of the Yangtze River estuary for food.

Is the Yangtze River paddlefish a mammal 3 0 1, the "living fossil" of fish-Yangtze River paddlefish.

Speaking of paddlefish, many people may feel familiar and unfamiliar. The familiar reason is that you can often see its related reports on the internet, and the strange reason is that no one has ever really seen it.

Because the white sturgeon has not appeared in the Yangtze River in China for nearly 20 years, there are only photos of the past. ACIPENSER ACIPENSER is a kind of fish in the family Polyodontidae, and it is an ancient creature on the earth. It lived on the earth as early as 65.438+0.45 billion years ago.

At that time, the earth was not only inhabited by a large number of paddlefish, but also distributed widely. However, 2-3 million years ago, the family of Polyodontidae was subjected to the most severe test, even almost extinct on the earth.

After the earth's climate turned cold at the end of Tertiary, the earth entered the "Quaternary Great Ice Age", and the earth's environment also changed greatly, which led to the gradual extinction of the originally widely distributed fishes of the family Polyodontidae, because it was difficult to adapt to the new environment of the earth, but fortunately, two fishes of the family Polyodontidae survived.

There were originally two kinds of Spodoptera fishes in the world: one is the extinct Yangtze sturgeon in China; The other is the long-nosed sturgeon distributed in the Mississippi River valley of the United States, which also lives in fresh water and has a large number.

Although American sturgeon and Yangtze sturgeon are the same species, their feeding habits are just the opposite to those of individuals. The Yangtze sturgeon is a carnivorous fish, while the American sturgeon is a filter-feeding fish, which mainly feeds on zooplankton and occasionally eats chironomid larvae and other foods.

American long-nosed sturgeon is a single individual, the largest of which is no more than 2 meters, and its weight is within 100 Jin, but sturgeon is a huge freshwater fish in the Yangtze River. So, how big can the paddlefish grow?

02, once the "Yangtze River Fish King"

In Sichuan, China, there is a jingle among local fishermen: "A thousand kilograms of wax is like ten thousand kilograms, and the yellow steak is too big to be decent."

The jingle in fishermen's mouth actually refers to three kinds of fish that inhabit the Yangtze River, namely sturgeon (1,000 kilograms of wax), white sturgeon (10,000 kilograms of elephant) and mullet (yellow steak). Comparing the sturgeon to an elephant, it can grow to tens of thousands of kilograms. You can imagine how big the sturgeon is! Although this sentence sounds exaggerated, it is not groundless.

According to Professor Bing Zhi, a famous zoologist, Nanjing once captured a sturgeon sturgeon with a body length of 7 meters and a weight of nearly one ton. The paddlefish is a large fish, which can grow up to 7.5 meters at most. In the past, the common individuals were 2-3 meters long and weighed about 200 kilograms. Therefore, the name of the "Yangtze River Fish King" deserves its name. At the same time, the paddlefish is also the largest freshwater fish in the Yangtze River, but it is not limited to fresh water.

Because the paddlefish is a semi-anadromous fish, it was born in a freshwater river. When it grows to a certain size, it begins to migrate to live near the coast, and then returns to Danshui River to lay eggs when it matures. The paddlefish is also the largest anadromous fish.

At first, it was mainly active in the Qiantang River and the East China Sea. Later, due to various reasons such as environmental deterioration, the population was forced to migrate to the Yangtze River basin and live between the Haihe River such as the Yellow Sea and the Bohai Sea, but it eventually became extinct.

In fact, as early as the early 1980s, China monitored a sharp decline in the population of Chinese sturgeon, and in 1983 and 1987, Chinese sturgeon was listed in the list of key protected wild animals twice, and upgraded to a national first-class protected rare animal.