Lake Baikal is the largest and deepest freshwater lake in the world, with an area of 31,500 square kilometers, an average water depth of 730 meters, and a maximum depth of 1637 meters. There may be a larger area in the world than Lake Baikal, but there is no deeper than Lake Baikal. Because of this width and depth, the pot is often mistaken for a sea, but others are real freshwater lakes, we all know that the ocean and the lake are two completely different ecosystems, freshwater organisms can not survive in the ocean, and marine life is difficult to adapt to the freshwater environment.
But Lake Baikal is rich in biological resources, not only live more than 2,000 kinds of freshwater animals, but you can also see seals and conchs and other marine animals here, especially the posters here, they have an exclusive title, Baikal seals. Baikal seals are also the only freshwater seals in the world, and according to recent statistics, there are about 80,000 living here today. To 100,000 seals.
Compared to other species of seals, the Baikal seal is the smallest of them. Adult Baikal seals are about a meter long. Their bodies were round and spindle-shaped, and the silver-gray fur on the surface was smooth and shiny. Don't look at their fat and round body, they seem to be very clumsy, but once in the water, they become extra flexible, they are skilled divers, swimming speeds of up to 20 kilometers per hour, and can stay in the water for more than 30 minutes, constantly preying on various public opinions and day and night.
They are widely distributed in various areas of Lake Baikal, and some of them prefer to be quiet, so they find a secluded place away from the shores of the lake to rest. Because of the cold winters in Lake Baikal and the harsh temperatures of the lake, all Baikal seals usually spend hours lazily sunbathing on the rocks surrounding the lake. But in our inherent understanding, seals are a mammal that lives in the ocean, so where did the seals in Lake Baikal come from? At present, the human exploration of Baikal seals is not enough, and their origin and origin are still an unsolved mystery. However, later analysis of the skull structure of the Baikal seal showed that there was some connection between him and the Caspian seal and that they were genetically similar.
So some scientists believe that Baikal seals may be descendants of Arctic ringed seals, and they have also proposed the following conjectures, the first of which is also a more common conjecture, that Baikal seals are from the Arctic Ocean because they have some similar blood relationship with seals in the Arctic Ocean, as early as 1909 in an article in The Sea Plains Magazine.
A similar conjecture was raised, that there was once seawater stretching from the Arctic Ocean to the area where Lake Baikal is now located, and that the second type of Lake Baikal may have been connected to the sea by a large number of water bodies at some time in the past. As the oldest lake in the world, Lake Baikal has a long history of about 30 million years, and the poster came here most likely during the Great Ice Age.
At that time, the Yenisei River and Angara River basin were covered by ice and snow for a long time, and most of the current Russian West Siberian Plain and West Siberian Glacial Lake were formed in the last ice age.