Piranhas are mainly distributed in the Amazon River in South America. They are also called piranhas. They are the collective name for the fish of the subfamily Cyprinidae in the family Cyprinidae. There are more than 30 species, and the body length can reach up to More than 30 centimeters.

In fact, piranhas are divided into carnivorous and omnivorous. The piranha we usually call is a carnivorous piranha, and its scientific name is Red-bellied Sawfish, or Nassian Sawfish.

The skull of the piranha is very hard, and the body is flat and oval. The piranha has a protruding lower jaw and short and powerful jaws. The teeth are very sharp, triangular in shape, and arranged staggered up and down. The bite force is amazing. Once it bites the prey, it does not let go and can easily tear off the prey's flesh.

Although piranhas are small in size, they are indeed fierce. Piranhas mainly feed on small fish, carrion, etc., but some recent species only eat plants and small fish. They often hunt in groups and eat their prey cleanly. Piranhas are extremely sensitive to the smell of blood, similar to marine sharks. The slightest smell of blood will trigger a group of piranhas to attack. When hungry, they may even attack their own kind.

Although humans and animals are both meat in the eyes of piranhas, piranhas are afraid of the weak and fear the strong. They rarely attack large animals such as humans. Instead, they are afraid that you will eat them. Piranhas that attack humans are usually Knott's sawfish.

Piranhas are not as scary as the legend says. The local indigenous people also regard piranhas as a delicacy. Go to the Amazon River to catch one, fry it until golden, and the kids next door will cry with envy. Piranhas in groups are very arrogant, but when piranhas are alone or in small numbers, they become very cautious and become cowards. When frightened, it will shrink into a corner and dare not move. If you are uninjured and swimming in the Amazon River, piranhas will almost never attack you.

Piranha attacks on humans are rare and usually only bite humans. It is said that in 2013, many people were attacked by a school of piranhas while swimming in the Paraná River in Rosario, Argentina. Many people were bitten with deep wounds, and one girl's finger was even injured due to bites. And amputation. The reason why piranhas attacked humans at that time may be related to the very hot weather.

Although piranhas are ferocious, they also have natural enemies, otherwise they would have dominated the Amazon River long ago.

The Amazon is rich in species, and piranhas also have many natural enemies. Otters, river dolphins, and crocodiles in the Amazon River Basin feed on piranhas, and some birds also prey on piranhas. Of course, humans are also natural enemies of piranhas. Although piranhas are ferocious, their size is so small that they can't make any waves in front of large animals.

The most powerful animal in the Amazon River is probably the electric eel. It can generate hundreds of volts of high-voltage electricity. In turbid waters, its effective attack range can reach several meters. When animals such as piranhas and crocodiles encounter Everyone will stay away. Electric eels have almost no natural enemies except humans.

Because piranhas are highly aggressive to other small fish, they can be kept for fun, but they are strictly prohibited from being released into the wild. Because it is an alien species in the native land and has almost no natural enemies, if it is released casually, if it develops, it may lead to the extinction of some native fish and destroy the balance of the ecosystem.

It can be seen that although piranhas have a scary name, they are actually far less threatening to humans than crocodiles.