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Friends in the Northeast know the "Silly Roe deer", "Silly Roe deer" scientific name is called the Oriental Roe deer or Siberian roe deer, they have a cute appearance and silly personality, like to jump in the snow.
So have you ever heard of the "silly roe deer in the water" – the Brazilian arapaima? Compared with the Northeast Divine Beast "Silly Roe deer", the Arapaima is really "stupid" and is on the verge of extinction because of its touching IQ.
<h1 class="pgc-h-arrow-right" data-track="4" > "silly roe deer in the water" arapaima, a "living fossil" that has survived for nearly 200 million years</h1>
Arapaima gigas, mainly found in Brazil, Peru and Guyana in South America, is a giant freshwater fish in the Amazon And the world's largest freshwater fish.
By its name, you know that this fish is not easy to mess with. The so-called "fish as its name", the giant bone tongue fish not only grows large, but also has a hard tongue in the mouth. The tongue of the arapaima is not as soft as that of humans, but is hard as a bone.
Therefore, the way they prey is also quite simple, opening their mouths to absorb water and sucking the small fish and shrimp nearby into their mouths, and then using their tongues as hard as bones to crush the food with their mouths.
Arapaima
In terms of body size, the arapaima averages more than 2 meters in length and weighs 100 kilograms when it reaches adulthood; it is called "the giant of the Amazon" by the local population.
The Amazon River is full of dangers, and there are swarms of piranhas and crocodiles in the water. Arapaima has lived here since the Jurassic era 187 million years ago and can be called a "living fossil" in the water. In order to adapt to the dangerous environment, they point out various strange skills on their skill trees.
First, the whole body is covered with hard "armor"
When we think of the Amazon, the first thing that comes to mind is the terrifying piranha. There are more than 30 species of piranhas in the river, which have sharp teeth and strong bite force. Even pythons living in the Amazon jungle do not dare to go into the water.
However, arapaima can live leisurely in the Amazon River and get close to piranhas. This is due to the hard "armor" on their bodies. This layer of "armor" is the scales of the arapaima, which is quite strong.
Piranhas have also tried to prey on arapaima, but to no avail. Because the layer of fish scales on the arapaima is really too capable of carrying. Their fish scales can reach a length of up to 10 cm and are divided into two layers. The outer layer is rich in calcium, which is as hard as ceramic, and the inner layer is collagen fiber, which can slow the impact.
In recent years, according to scientists, another peculiarity of arapaima scales has been discovered - the Bouligand structure.
Structure of arapaima scales
The so-called Bollinger root structure is a large number of nanofibers stacked on top of each other, similar to mille-feuille cake. When impacted by external forces, the stacked nanofibers can effectively dissipate the impact kinetic energy.
It is completely impossible for a piranha to nibble off this layer of scales. Even when human chefs cook arapaima, they have to use a hammer to knock down their scales.
Second, it can breathe with the gills of the fish, and it can also breathe with the "lungs"
When the Amazon Reaches the dry season, there will be a lack of oxygen. Because the water level drops during the dry season, and a large number of corpses appear in the river, the decomposing organic matter will consume some oxygen. Trying to survive the low-oxygen period of the dry season, arapaima has evolved a new skill – it can breathe with its gills and breathe with its "lungs".
However, this "lung" is not a real lung, but a fish maw. The arapaima swim bladder, in the course of evolution, covered the entire kidney. The blood vessels of the kidneys pass through the portal venous system, which in turn is connected to the heart. Arapaima can then supply the air in the maw to the heart through the renal portal venous system.
Arapaima fish maw (blue)
Therefore, when there is not enough oxygen in the water, the arapaima will surface and breathe in the air with its mouth. In fact, 80% of the oxygen consumed by arapaima comes from air and 20% from water.
Due to the greater reliance on breathing air, the gills of all arapaimas experience some degree of degradation. However, it also has a certain function of breathing and removing carbon dioxide. It is worth mentioning that because the arapaima uses the swim bladder as a "lung", they can survive for 30 minutes after leaving the water.
Third, the male is responsible for taking the baby and can also breastfeed
As we all know, fish are oviparous animals, and when children hatch from fish eggs, parents are basically fine. But arapaima is different, after spawning, the mother fish and the father of the fish will take turns to guard the eggs until the child hatches safely.
After the child hatches for about a month, the task of the mother fish is over, and she can enjoy the raw fish freely. But the fish father still has to shoulder the responsibility of taking the baby, and he will follow the child for about three months.
Scientists have found that fish fathers follow their children, mainly to "breastfeed" their babies. Whenever the breeding season, arapaima produces "milk" both male and female, and they have two small holes in their heads that will flow out white "milk", which has no nutrition but the fish dolls like to drink.
In 2017, researchers at the University of Stirling, Lucas S. Torati, and colleagues found that the "milk" of arapaima comes from the inner ear, eyeball, and central nervous system, and contains some hormones and a large number of proteins related to immunity.
These hormones and immune proteins, although they can not directly provide nutrition to fish dolls, but have the effect of coordinating parent-child relationship and enhancing immunity.
Arapaima longer than a human
<h1 class="pgc-h-arrow-right" data-track="4" > Arapaima is a protected animal and is endangered due to its touching INTELLIGENCE</h1>
Arapaima is "armored", has two sets of respiratory systems, and can "breastfeed" children, even piranhas can't do anything with them.
Awesome, right? IQ changed.
Arapaima is called "silly roe deer in the water" because of its low IQ and strong curiosity. There's a little movement and sound on the surface of the water, and they're going to make a scene. So the Brazilian locals catch arapaima is very simple, drive a small boat on the river to make some movement, wait for the fish to take the initiative to probe over, a stick to knock over.
Fishing arapaima is easy with one person and one boat
Perhaps too easy to catch, and with the fact that the fish is not as tasty as a small spine, the locals are frantically fishing for arapaima. So in the 1970s, the number of Brazilian arapaima in the Amazon basin began to decrease. In recent years, the indiscriminate deforestation of the Amazon rainforest has also exacerbated the decline in the number of arapaima to a certain extent.
In 1986, arapaima was listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and in 2001, Brazilian legislation prohibited commercial fishing of Arapaima brassica outside designated areas.
Although Brazilians have begun to protect arapaima, the ancient fish that has lived for nearly 200 million years has been too low for the International Union for Conservation of Nature (IUCN) to count, after all, their distribution is too sparse to accurately count.
Arapaima that can only be lifted by four people working together
Maybe one day in the future, Arapaima will disappear from the earth.
<h1 class="pgc-h-arrow-right" data-track="4" > postscript</h1>
Human activities have had a great impact on arapaima; it is not only arapaima that has suffered the same, but most species on the earth have more or less declined populations due to the environmental damage caused by human activities. For example, polar bears, whales, etc.
The earth is not only home to human life, but also to other animals. I hope that each of us can love the environment and give ourselves and other lives on this planet a good living environment.