Maybe it’s unbelievable, isn’t it? Nature is such a cruel test of all things in the world, in order to survive, we have to choose evolution; in order to survive, we have to learn to adapt to the environment. This kind of fish that Xiaobian wants to talk about today is a kind of fish that can adapt to the cruel environment around and survive in difficulties.
It is called lungfish. It is a kind of fish that mainly lives in Africa, but it is also distributed in South America and Australia. It is a very old species, from the early Devonian life so far, has been constantly adapting to the environment. Even without water, it can live in the soil for four years!
The reason why it is called “lung fish” is that its respiratory organs are obviously different from other fish, similar to our earliest lungs, but it does not use lungs, it uses swim bladder. That is to say, when it is in the water, it can breathe with gills like other fish, but if it is dry, it can breathe with “lungs” in the air. This is also the main reason why it can adapt to the changes of the surrounding environment.
For many places, lung fish is a precious living fossil, but in many parts of Africa, the number of lung fish is very large, and widely distributed in the river silt. Because of its huge size, its body length can reach more than 1 meter and its weight can reach 10 kg. So in Africa, lung fish has become a common food around people. For Africans, going to the mud to “dig” lung fish is like pulling out a radish!
Maybe you want to say that lungfish will not die of thirst due to lack of water in case of drought?
The most amazing place for this kind of fish is here. When it encounters drought, it will drill into the soil, and then enter a dormant state to keep its water from losing to the outside world. They can easily survive for two years in this way. There was an experiment in Africa where they built a lungfish into a mud wall and lived through a long drought. Four years later, when the rainy season came, the lungfish was awakened again, got out of the soil and ran into the water.