1. It has survived on earth for hundreds of millions of years
When it comes to the Amazon Basin, it may be the mystery that comes to mind first, followed by the mention of the most famous fish in the Amazon, and perhaps the first thing that everyone will think of will be the piranha.
Whether it is in the science and education column or on the Internet, as well as in some TV movies, the "legend" about the piranha is extremely rich, this small freshwater fish, but in just 1 minute, the animal can be chewed to the skeleton, maybe anyone who sees it will have scalp numbness.
However, in the Amazon basin, there is still such a fish, they use piranhas as a "snack", the scales on the body are like armor, and the kitchen knife cannot shake it.
Arapaima is a remnant of the paleo-freshwater fish, which is presumed to have appeared as early as 100 million years ago, and is known as arapaima due to the growth of bony teeth in the tongue. With a huge body length of more than 2.5 meters, a maximum length of 3 meters and a weight of up to 200 kilograms, it is the largest freshwater fish in the world.
2, wearing armor "knife and gun can not enter", the piranha as a "snack"
Compared to the short, thin scales of common freshwater fish, the scales of arapaima can reach 10 cm in length and are arranged in two layers in a Bollingernic structure. The outer layer of fish scales is rich in calcium, hardness and ceramic, and the inner layer is collagen fiber, which can effectively slow the impact, which also makes them have a higher defense than crocodiles.
Some indigenous people living in the Amazon basin often take off the scales of arapaima and use them as a portable knife. In the face of the attack of the piranha, this layer of defense of the arapaima can be called an "invincible" existence, and it is impossible to break the defense, and the piranha can only be slaughtered by the arapaima.
Even when we humans cook arapaima, we need to use tools such as hammers to knock down their scales, because their scales can't even be cut with a kitchen knife.
Arapaima have bony teeth in their tongues, which also allow them to easily shred their prey, they feed mainly on small fish, but occasionally prey on snakes, turtles, frogs and insects, and sometimes they will swallow them in the face of plant fruits that fall on the surface of the water, and even some smaller crocodiles, after encountering arapaima, have no chance of surviving.
Arapaima eats a bit like baleen whales – opening their mouths to suck. To put it bluntly, it quickly opens the mouth, creating a vacuum stream that causes food to be sucked in. Don't look at the way they eat, but Arapaima has brute force, and the strength of their tails can easily break our skulls.
In the Amazon rainforest, arapaima is like a moving fortress, both with armor close to "invincible" for self-protection, and brute force can also help them launch powerful attacks, which can be described as a combination of attack and defense.
3, can breathe in the air, extremely like to "join in the fun"
In nearly 100 million years, in order to survive better, arapaima have also evolved "lungs", but strictly speaking, the "lungs" of arapaima should be fish maws.
The maw of the arapaima covers 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.
When the amount of dissolved oxygen in the water is insufficient, the arapaima will float to the surface to breathe, and they can survive for more than 30 minutes after leaving the freshwater, which is already very eye-catching in freshwater fish.
Compared with the timidity and caution of ordinary freshwater fish, arapaima is extremely fond of "joining in the fun", perhaps this is related to their extreme self-confidence, just imagine, the almost "invincible" defense makes them fearless, and when they are busy, they may be able to "hunt and add a dish." ”
A group of photographs was taken of a group of children playing by the water's edge, and the sound attracted the attention of arapaima, and it wasn't long before several fish swam to the shore and poked their heads out of the water to observe the movement on the shore.
5. A generation of kings lost to the mallet
Catching an adult arapaima can get nearly 70 kilograms of fish meat, and the meat of arapaima is delicious and tender, has a high nutritional value, and is so popular in the market that the locals have begun to pay attention to them.
As mentioned earlier, arapaima is very fond of joining in the fun, and local fishermen have also discovered this feature, they will deliberately make a movement on the surface of the water to attract the arapaima, followed by a wooden tool to knock it out, and then catch it ashore.
Arapaima, which originally stood at the top of the food chain, could "do whatever it wanted" in the amazon rain forest without natural enemies, but it was heavily fished because it had a high value in the human market.
At the same time, the arapaima is too simple to catch, because they will stick their heads out when they are busy, and the result is a violent blow that awaits them, although it cannot be fatal, it will cause dizziness, and then there is only someone to slaughter, some experienced fishermen, alone can easily catch a boat of arapaima.
In this context, the number of wild arapaima is also declining rapidly, and a hundred years ago, every year, just one port in the port of Belém in Brazil, the catch of arapaima exceeded 1200 tons, and you can imagine how huge the number of fishing in South America is.
However, with the sharp decline in arapaima populations, in 1986 arapaima was officially listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES); According to incomplete statistics, the number of individual populations of wild arapaima is now in the range of 50,000-100,000.
While fishing is prohibited, many countries are also beginning to artificially cultivate arapaima, after all, this fish has a relatively rich market value. What should have been the "king of a generation" in fresh water was ultimately defeated under the mallet.
"There is no harm without trading", the decrease in the number of arapaima, in addition to their own "silly" like to join in the fun, and our human wanton hunting is also inseparable.