The 'monster' on the Amazon River can smell 1 drop of blood in 200 liters of water, indigenous people do not dare to touch!

If the longest river in the world is the Nile in Africa, the largest river in the world is the Amazon River - this river has the largest basin and the most water flow in the world. At the same time, the largest tropical rainforest in the world is the Amazon rainforest, most of which is located in Brazil. The two are closely tied together to create the most diverse flora and fauna on the planet.

The Amazon rainforest is known as the "lungs of the Earth", the air is quite fresh, it also has ancient green forests and winding rivers, looks very beautiful and attracts a lot of people to come. this. It is home to the most species in the world, with more than 2.5 million species of insects and more than 10,000 species of plants and thousands of species of mammals, such as pythons, yellow parrots, freshwater dolphins. .

But underneath these beautiful scenes and biodiversity lurks very scary dangers.

What makes the Amazon River so terrible? And why don't people dare to swim in it?

Besides the fact that the Amazon is home to the giant python Anaconda and countless other carnivores, one of the reasons comes from the name "Piranha".

Assassin in the riverbed

The Amazon River is infamous for its fearsome and terrifying "Piranha fish", which has many fangs and a crazy bite force that can hunt in groups. There are many opinions that they can eat a cow weighing 450 kg in 70 seconds. All remains are skeletons.

Analyzing Piranha's infamous power, Smithsonian Magazine (USA) said the factors that make Piranha a "nightmare" for many creatures in the riverbed:

1. Sharp teeth

Piranha fish are known for their razor sharp teeth and relentless bite. (The word piranha is literally translated as 'serrated fish' in the Brazilian Tupí language.) True piranhas have tricuspid teeth, with larger/longer incisors.

The sharp teeth of the Piranha fish.

The shape of the piranha's teeth is often compared to the shape of a saw and this has clearly been adapted to their carnivorous diet. The actual enamel structure of this fish is similar to that of a shark.

It is not uncommon for Piranhas to lose teeth throughout their lives. However, while sharks change their teeth individually, Piranhas change teeth and teeth many times over their lifetime, lasting up to eight years in captivity. It is not unusual for a Piranha to be missing half of its lower jaw.

Piranha fish come in many varieties and they are both vegetarian and carnivorous. Their common foods include insects, fish, crustaceans, worms, carcasses, seeds, and other plant materials.

Specimens of the jawbone of the red-bellied Piranha (Pygocentrus nattereri). Wikimedia Commons / Sarefo

In a 2012 study in the journal Scientific Reports, researchers found that the black (or red-eyed) Piranha (Serrasalmus rhombeus) -- the largest of modern species -- bit with maximum force. is 33 kg (3 times their body weight).

Using fossil tooth models, they discovered that the 10 million-year-old extinct ancestor of the Piranha fish, Megapiranha paranensis, had a bite force at the tip of the jaw as high as 484 kg. For reference, this Megapiranha paranensis species when alive weighs only 10 kg, which means that the bite force of Megapiranha paranensis is almost 50 times their body weight.

Science notes that the estimated bite force of the T.rex Tyrannosaurus rex is more than three times higher than that of the ancient Piranha fish (Megapiranha paranensis) - but the "king of reptiles" is the dinosaur T.rex. much heavier.

2. Ultimate hunting strategy

Not only possessing scary teeth, Piranha fish also possess a very clever prey attack strategy. A 1972 study of red-bellied piranhas found that this fish most frequently attacked goldfish in a laboratory setting starting with the tail or eyes of its prey.

The researchers concluded that such an offensive strategy would immobilize or disorient the piranha's opponent.

A scene of Caiman crocodile eating fresh Piranha fish in Venezuela. (Photo: W. Perry Conway / CORBIS).

In addition, it is easy to see Piranha fish often move in schools. They do it for safety.

Piranhas are not at the top of the Amazon riverbed food chain. They prey on Caiman crocodiles, birds, river dolphins and other large Pescatarian fish. So walking in groups in the shoals protects the fish inside from being attacked.

3. Sensitive to noise and blood

A 2007 study linked noise, splashing water, food, fish or blood into the river with three cases of piranhas attacking humans in Suriname.

As for blood, Piranha fish can smell a drop of blood in 200 liters of water. So, if you have a minor wound, it's not wise to take a dip in the Amazon River bed!

4. Piranha only attacks when threatened

And although piranhas are notorious for attacking people, there isn't much evidence to back this up. Like grizzly bears, wolves, sharks and pretty much every big scary thing with teeth, Piranha fish will leave you alone if you leave them alone.

The Black Piranha and the Red-bellied Piranha are considered the most dangerous and aggressive species for humans. However, veteran South American swimmers often emerge from piranha-rich waters without losing their flesh.

For the average person, danger occurs you move in low water, prey is scarce (with the Piranha) or you disturb its spawning ground in the riverbed - These are basically situations that the Piranha feel is really threatened or when they are really hungry - so they will become more aggressive.

That's why, indigenous people rarely wade barefoot on the river's edge. For them, hunting and eating Piran ha is taboo, so they rarely touch this fish.

Scientists advise non-specialists not to go or swim in the Amazon River bed, to avoid misleading them (disturbing or potentially dangerous) so that they attack people.