Piranhas (also known as piranhas) inhabit main streams, larger tributaries, wide river widths, and fast currents. In the Brazilian Amazon, piranhas are ranked among the top four most dangerous aquatic creatures in the region. In the Brazilian state of Macedo Grosso, where piranha activity is most frequent, about 1,200 head of cattle are eaten by piranhas in the river each year. Some children playing in the water and women washing clothes are also attacked by piranhas from time to time. Piranhas are known as "water wolves" and "water ghosts" because of their ferocious characteristics. Adults mainly feed at dawn and dusk, mainly insects, worms, fish, but some of its similar species only eat fruits and seeds. Activity is predominantly during the day, with resting in sheltered areas at midday.
Mature piranhas are similar in appearance between males and females, with bright green backs and bright red bellies with markings on the sides of the body. There is a highly developed sense of hearing. Both jaws are short and powerful, with the lower jaw protruding, and the teeth are triangular, sharp, and interlocked above and below each other. It bites down on its prey and then clenches, tearing the flesh off with a twisting motion of the body, and can bite down as much as 16 cubic centimeters of flesh in a single bite. The rotating replacement of teeth allows it to feed continuously, and the powerful array of teeth can cause serious bite wounds.
During the breeding season, it lays its eggs, which are adhesive, on roots in the water. Thousands of eggs can be laid at a time. The parent fish will protect the eggs and the fertilized eggs will hatch after 9 to 10 days. River flooding affects its reproductive success.
Piranhas are often found in schools, each with a leader, and the others follow the leader's lead, even when attacking the same target. During the dry season, the waters become smaller, allowing the piranhas to gather in large schools, making animals or people passing through these waters vulnerable to attack. It has long been thought that the smell of blood is the main cause of attacks by large schools of piranhas, but it is also thought that the noise and splashing caused by injured animals attracts their attention
As the saying goes, "Big fish eat small fish, and small fish eat shrimp." But in some lakes and rivers in the Amazon basin of South America, there grows a kind of fish that is not afraid of big animals and is very aggressive.
So what monsters lurk in these lakes and rivers?
American explorer Doolin made a special trip to investigate, and he witnessed a large bird attempting to hunt the fish in the water. The large bird dashed into the water in a swooping position, only to struggle up and eventually sink. Doolin was so amazed that in order to solve the mystery, he tied a goat to a rope and pushed it into the water. Within seconds, the lake was violently churning. five minutes later, he pulled up the rope and saw that only the skeleton of a goat was left, and the flesh on the skeleton had been gnawed clean off.
Durin found several small, strangely shaped fish in the goat's chest bone, which dropped to the grass and jumped about, biting whatever they came across. Their heads were black on both sides and their bellies were orange, only 6 centimeters to 7 centimeters long, but strangely the mouths of the small fish had two rows of teeth as sharp as blades.
The study found that this is the Amazon River Basin endemic "piranha", locally known as "water ghosts".
Why is the piranha so powerful
According to biologists, there are more than 20 kinds of piranha have been found, not only in the Amazon River Basin, east of the Andes Mountains in South America, from the southern coast of the Caribbean Sea to the northern part of Argentina, some of the Latin American countries have traces of piranha.
The piranha's body size is small, but its temperament is very fierce and brutal. Once the bitten prey overflows with blood, it will be mad as hell and use its sharp pointed teeth to frantically tear and cut like a surgeon's scalpel until a pile of skeletons remains.
Why is the piranha so powerful? This is because of its short neck, skull, especially the palate bone is very hard, the upper and lower palate of the bite force is amazing, can bite through the cowhide and even hard boards, can be made of steel fishing hooks a bite off, other fish of course, it is not its opponent. Usually in the water king of the crocodile, once encountered the piranha, will also be scared of shrinking into a ball, turning the body face to face, the hard back down, and immediately floated to the surface of the water, so that the piranha can not bite into the abdomen, to save their own lives.
The piranha's life is divided into group living and solitary living, group living often hundreds or thousands of them gathered together, the smallest 6 can also be a group, can use vision, smell and water vibration at the same time sensitive feeling to search for attack targets. However, it has poor eyesight and relies on its discus-like body shape to distinguish between similar species.
Piranhas have the guts to attack animals several times or even dozens of times larger than themselves, and they have a well-established "siege tactic". When they hunt, piranhas always first bite the fatal parts of the prey, such as the eyes or tail, so that it lost the ability to escape, and then attacked in groups in turn, one after another, rushed forward to bite, and then get out of the way for the back of the fish to leave the position, and quickly the target to zero, the speed is incredibly fast.
Why the piranha struggles to dominate the Amazon
Many people are baffled by the question: if the piranha is so powerful, why isn't it sweeping away the animals of the Amazon?
The piranha's main food is not, of course, people, monkeys, cows or other mammals that have fallen into the water, because this kind of waiting-and-waiting style of hunting doesn't get it to its next meal; their main target is a variety of other fish.
However, hunting other fish in the rivers of the Amazon Basin is not easy for the piranha because the water is so murky that visibility is usually no more than 1 meter, and the piranha can't be more than 25 centimeters away from its prey when it launches an attack.
Piranhas don't swim fast enough, which is no doubt a blessing for many fish, but the surprise attack when feeding is extremely fast. The slow swimming speed is blamed on the piranha's discus-shaped body. Why didn't long-term biological evolution give it a slimmer body? Scientists believe that the discus body shape is a cosmetic sign that all species of piranhas recognize each other, a sign that serves to discourage piranhas from cannibalism.
In order to deal with piranhas, many other fish have developed their own "cutting-edge weapons" over centuries of competition for survival. For example, a single electric eel can send more than 30 piranhas to the "electric chair" for execution, and then slowly eat them.
The spiny catfish, on the other hand, makes good use of its sharp spines, and once it is targeted by the piranha, it swims as fast as it can to the bottom of the belly of one of the piranhas, and no matter how the piranha swims, it synchronizes its movements. Piranha want to it down to the mouth, spiny catfish immediately spine angry open, so that the piranha can do nothing. In addition, in and in the Amazon River killers ranked first spiny catfish, piranhas only ranked fourth.
The piranhas also have a unique ability to be vicious only when they are in groups. Some fish lovers have a piranha in a glass tank, in order to show his bravery in front of the guests, sometimes he deliberately put his hand into the water, in most cases he is safe. If the finger is injured it's a different story.
If a guest approaches the tank or the owner makes a sudden gesture, the piranha, known as the "terror of the Amazon," retreats to the farthest corner of the tank. It was clear that the piranhas, usually formidable in a group, had become pathetic cowards once they were separated from the group.
Ukrainian fish experts, after viewing the piranhas captured in Dnepropetrovsk Oblast, concluded that the uninvited guests were released by humans, and that the water temperatures in Ukrainian rivers and lakes have been able to satisfy the piranhas' need to survive since spring, so they are free to survive and begin reproducing after being released. Although the tropical fish will freeze naturally when water temperatures drop in winter, the fish could still pose a threat to waterfowl and human safety if they are not caught and killed during this summer and fall.
Injuries to piranhas are relatively rare in the Amazon River Basin, and they have been unofficially introduced as ornamental fish in this country for more than a decade. Recently due to ignorant news media hype in the fish market has been very rare, and because of the appearance of not very good-looking, only love it in the hands of professional fishers can see. The lowest price are more than a hundred dollars, rare varieties such as "violet" is as high as ten thousand dollars hard to find a fish. A few dollars a common market known as piranha is mostly its close relatives of the red-bellied pomfret. Is our country in the early years as a food fish introduced from Brazil.