Fishing, the most important thing is the process, and it is best to be happy. But in Africa, people here fish without fishing rods, just shovels and hands.
Fishing doesn't require going to the river, it just needs to find a dry field and look at the target to dig. Fishing thus becomes digging fish, is this possible?
How can not slip out, flower drops the world ~
It's not that the African people are working in a fancy way, it's just that this fish does live in the soil and can't be dug out without a shovel. Lungfish is probably the most bizarre species on earth today, and no other fish will stay in the soil like lungfish. And this stay can be several years, although they are hidden in the soil and still can not hide from human excavation.
Why can lungfish survive in the soil? How do they live on land? What is the difference between lungfish and other fish? Are lungfish fish really fish? This article will answer these questions from the aspects of the evolution of lungfish, the ecology and life history of lungfish. Next, let's take a look at the African lungfish that have been hidden deep underground for several years without eating or drinking, why have they not escaped human excavation? Lungfish said: This is so sad!
Fortunately, I am not a "Chinese lungfish", otherwise I would have been eaten and extinct
Live fossils of fish
Although lungfish can survive on land, they do belong to the category of fish. Lungfish are vertebrates under the order Carnotodontes and live mainly in fresh water. Fossil evidence of lungfish suggests that they were widely distributed around the world from the triassic period onwards. Modern lungfish are mainly preserved by the remaining species after the disintegration of pangaea.
The structure of the African lungfish swim bladder is very similar to that of land animals
The evolution of lungfish began around the Devonian Period 420 million years ago, when leaf finfish gradually adapted to the survival of parts of the water and land, and thus evolved into coelacanth and lungfish, which are the two surviving lung-breathing fish.
Unlike leaf finfish, lungfish evolved their lungs earlier than those of leaf finfish, and their common ancestor finfish had lungs, but in later evolution, most finfish evolved their lungs to keep themselves floating, and few lungfish evolved to keep breathing. Although coelacanths and lungfish are similar in division, lungfish are more closely related to other animals than tetrapods.
Will these four "little whiskers" become four feet if they are successfully evolved?
Almost all of these studies have come from the anatomy and body morphology of lungfish, which, in a convergent evolutionary perspective, evolved a quadruped-like posterior nostril. It is a nasal transitional organ of quadrupeds, including humans and other mammals, located between the nasal cavity and the throat, and its appearance in later evolution allowed animals to transition from water to land.
However, lungfish have hardly changed much since they evolved here, and one of the most powerful parts of the entire body structure of lungfish is that they can breathe in the lungs and can maintain a relatively static state for a long time.
All the creatures on land came from the first fish that migrated to land to live
These changes allow lungfish to live in drought and water shortage places for a long time, even if they do not eat or drink for 4 to 5 years, lungfish will not die, so how do they do it?
Fish that can live on land
The lungs of lungfish are a highly alienated respiratory system, most notably in the fact that their posterior nostrils are connected to the lungs and larynx, and there is no trachea. In general, if fish want to survive on land, usually the fish has evolved a vascular air sac that stores air through the air bag to complete the breath exchange.
Lungfish, on the other hand, evolved lungs with many tiny air sacs, which maximizes the surface area of their gas exchange and therefore more oxygen. When the lungfish breathes, the spiral flap of the arterial cone opens, then the bypass arterioles of the third and fourth gill arches close, and the second, fifth, and sixth gill arch arterioles open.
Schematic diagram of the respiratory system of the African lungfish
Ductus arteriosus Here, the branch of the sixth arteriole is open, while the pulmonary artery is completely closed. When water passes through the gills, the lungfish pumps through the mouth, and the flow through the mouth and gills is one-way. This allows the lungfish to maintain a stable gradient of blood flow concentrations.
The cardiopulmonary system of the lungfish preserves the mixture of oxygen to the greatest extent, while the water solubility of carbon dioxide can also ensure that the oxygen concentration is within a reasonable range. The bi-directional structure of the lungs allows carbon dioxide and oxygen to spread evenly, effectively maintaining land respiration.
Schematic diagram of the respiratory system of the South American lungfish
In addition to the West African lungfish, the Australian lungfish is also a local endemic lungfish, and unlike the West African lungfish, the Australian lungfish will fully use the gills to breathe after completing the lung gas storage. In addition, Africa is also the largest place for lungfish species, and there are four species of lungfish in the world that live in Africa.
However, Africa is not a smooth wind and rain, and most of the time, African lungfish face severe droughts, usually lasting several months. This forces lungfish to complete their survival in another way, to dissolve their cocoons.
Under the influence of global warming, There are frequent delays in rainfall and decreases in rainfall in Africa
When the lungfish perceives that the water in the river or field is gradually drying up, the lungfish will make a hole in the mouth of the next few days and drill into it. At this time, the lungfish will secrete a large amount of mucus, which can help the soil to complete the agglomeration, and it can seal the hole, leaving only the mouth of the lungfish outside.
Usually this happens during summer droughts, so for lungfish, they also have summer sleep. After entering the summer sleep, the entire physiological activity of the lungfish is reduced to a minimum, all unnecessary consumption will stop functioning, including the excretion of urine, and the heartbeat will be almost at rest. They will remain in this state until the next rainy season comes.
In order to adapt to the arid environment, the clever little brain melon came up with a very cattle coping strategy~
This kind of summer sleep can last up to 5 years, and the whole process does not eat or drink, only consumes the muscle sugar of the tail to maintain survival, which allows the lungfish to obtain the greatest possibility of survival at a very low consumption. However, the lungfish did not expect that they were hidden in the mud, and they were still targeted by humans.
Tragic lungfish
In many parts of Africa, the mode of production can be said to be almost non-existent, backward industrial level, most people are still carrying out manual work, especially in poor areas, it is not easy to eat a full meal.
To find me in such a small hole, garlic paste!
After the lungfish are found in Africa, the indigenous people of Africa will dig out the lungfish. First of all, they will look for traces in the place where the lungfish once lived, because the lungfish did not completely block the opening, so the lungfish cocoon will leave a small hole, and people will look for the lungfish through this small hole.
In Uganda, for example, lungfish are a staple food for the locals. It is said that the taste of lungfish may not be very good, and people who like it will love the unique flavor of lungfish, but people who hate lungfish will not eat it. Sometimes locals will also take this fish to the market to sell or exhibit it.
African people think that African lungfish have a strong "mud taste" when eaten
The lifespan of lungfish is generally about 20 years, which is a good result in the lifespan of fish. When food is plentiful, lungfish will eat aquatic insect eggs, small crustaceans, amphibians, etc. In addition to the fact that the indigenous people of Africa are interested in lungfish, scientists are also curious about the creature of lungfish.
For scientists, a key point is how the cocoons made by lungfish keep them in a normal state. Because zoologists believe that even if the lungfish wrap themselves up, they should be harmed by various germs, and drought is only one aspect of the impact.
Germs are a major survival problem for all living things on Earth
The latest research shows that the fish cocoon made by lungfish is not so simple, it is not just a mud shell. In fact, during the cocooning process of lungfish, the large amount of mucus they secrete will complete a body fluid exchange.
This mucus contains the lungfish's own white blood cells, which scientists call "granulocytes." These cells form a cell capture net that separates most of the bacteria from sepsis, skin infections, and blood loss. And these granulocytes will also cling to this pile of mucus for division, which means that the entire cocoon chamber is actually a bioprotective chamber.
So, my survivability is among the best on the entire African continent!
This explains why lungfish can remain unchanged in the soil for several years and have sufficient vitality after excavation. Because they are hardly infested with germs, it's all perfect if people don't dig it up.
May there be no hunger in the world and a promising future for the African people and the African lungfish
However, there are still many poor areas in Africa, and people still have not been able to get out of the status quo. The lungfish's painstakingly finished cocoons were dug up in the laughter of the African people, and for them, it was a godsend. For the lungfish, it is undoubtedly a disaster, and ten thousand sadness cannot describe the bitterness of the lungfish. The unique work that has evolved over hundreds of millions of years has actually been cracked by human beings.