Piranha fish. Piranha fish lifestyle and habitat

If you conducted a survey about which fish is the most dangerous on Earth, piranha would definitely be among the top three. Despite the rather small size of the fish itself, a school of piranhas in a matter of minutes will leave only a skeleton of a person who has fallen into the water. At least, this is what happens in numerous horror films and horror books. But is this really so?

The compressive force of the jaw muscles relative to body size is the highest in piranhas compared to any other vertebrate in the world.

First you need to understand whether the piranha is really an extremely aggressive creature that attacks everything that moves in the water. This may sound unexpected, but piranha is a very cautious fish and does not pose any danger to humans. Exists a large number of evidence of a person swimming in piranha-infested water without any harm to his health. This was fully demonstrated by Herbert Axeldorf, a famous biologist specializing in the study tropical fish. To prove the safety of piranhas for humans, Herbert filled a small pool with piranhas and dived into it, leaving only his swimming trunks on. After swimming for some time among the predatory fish and without receiving any harm to his health, Herbert took fresh blood-soaked meat in his hand and continued to swim with it. But several dozen piranhas in the pool still did not approach the person, although quite recently they happily ate the same meat when there was no one in the pool.

Piranhas, considered fearsome predators with an insatiable thirst for fresh flesh, are actually rather timid fish that do not dare to approach large creatures.

It is known that piranhas prefer to stay in large schools, and if one piranha is seen in the water, there are always others nearby. But piranhas do this not because it is easier for a school of predatory fish to overwhelm and kill a person who enters the water, but because piranhas themselves are a link in the food chain for other larger species of fish. Being in a flock of dozens of individuals, the chance that you will be eaten is quite low.

Moreover, experiments with piranhas have shown that when alone, these fish do not feel as calm as if they were surrounded by other fish.

But despite their peaceful behavior towards humans, piranhas are real killing machines for other fish species that are lower than them in the food chain. Their powerful jaws are designed to bite and tear, and their dense, muscular bodies are capable of incredibly fast movements and jerks underwater. The piranha's jaw muscle contraction force relative to body size is believed to be the highest of any other vertebrate in the world. For example, the common piranha can easily bite off the finger of an adult.

But in history there has not been a single reliable case of a piranha attack on a person with fatal. But this does not mean at all that these fish never bite a person or an animal that enters the water. And this behavior is almost always caused not by the aggressive behavior of the fish, but by self-defense or abnormal weather conditions, because of which the behavior of piranhas begins to differ sharply from usual. Abnormal weather conditions mean a period of drought, when the rivers in which piranhas live dry up, and many fish remain in depressions filled with water, but cut off from the main channel, deprived of food. Starving predators gradually begin to eat themselves and may well rush at any creature that comes close to the water. Sometimes the tendency of piranhas to behave aggressively is recorded during the spawning period, when they rush at a person or animal in self-defense, but such cases are extremely rare. And of course there is no talk of a collective attack by piranhas on humans.

But all of the above does not mean that piranhas will refuse to eat human flesh. Unfortunately, sometimes tragic incidents occur on the water - people or animals drown. An already lifeless body floating in the water attracts many fish, including piranhas, which leave specific bites on it. People who see this think that the cause of death was an attack by piranhas - this is how most myths about attacks by flocks of piranhas on people or animals are born.

This is interesting: suppose, in some unknown way a huge flock 400-500 piranhas were driven crazy, and now they attack everyone who is in the water. For example, if this unfortunate person turns out to be an adult, then 500 piranhas will be able to gnaw him to the bone in 5 minutes!

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Since childhood, these “cute fish” have scared me, especially after watching numerous horror films. In the films one could see the boundless cruelty and deceit of these creatures. But, in fact, they are not as scary as they might seem. Let's go, I'll tell you where do piranhas live?

Where do piranhas live?

PIrani live in bodies of water fresh water, which are located In South America. Most of them are found in the waters Amazon River. Piranhas exist in bodies of water Paraguay, Argentina and Uruguay. There are about 20 species of these predators. The size ranges from half a meter to several centimeters.

Not all individuals attack humans, but only some of them. If you escape with a small scar, then you are already very lucky. There are quite a few real cases, when a person was left without a finger after being attacked by these predatory fish.

The most unusual habitat piranhas- This home aquarium . In such conditions they lose their aggressiveness. They often become timid, trying to hide in various shelters. The aquarium should be placed away from constant loud noise. No matter how strange it may sound, these are very shy fish. More and more more people they want to breed this predator. This won't surprise anyone anymore.

Can be found in various aquariums. There they are trying to create as much as possible natural environment, which will be familiar to a given predator.

Appearance of a piranha

Majority piranhasare herbivores completely avoiding foods of animal origin. Coloring, like size, depends on the type of predator. The most common are silver-gray individuals. They have a diamond-shaped and high shape body, compressed at the sides. The predator has low-set eyes and a high forehead.

Piranhas have an unusual jaw structure. The triangular teeth are incredibly sharp, like a blade. They help tear apart the victim's body without much effort, tearing off pieces of meat. The jaws of these creatures are so strong that they can easily bite a bone.

I would like to talk about some of the features of these predators. So:

Aggressiveness depends on the time of year, temperature, etc.
One drop of blood can attract a school of piranhas located a couple of kilometers away.
They are considered river orderlies, cleaning water bodies from dead fish and plants.
Piranhas do not attack if they are full.

Are piranhas dangerous for humans? June 24th, 2018

Based on films and fiction books we know that if you put your hand in the water where piranhas live, they will gnaw it off in a minute. Well, okay, maybe this is not accurate, but if there is some kind of wound on the body and blood gets into the water, then the piranhas can smell it a kilometer away and will definitely attack a person with the whole flock and certainly only a skeleton will be left of him.

Is this really true?

This was fully demonstrated by Herbert Axeldorf, a famous biologist specializing in the study of tropical fish. To prove the safety of piranhas for humans, Herbert filled a small pool with piranhas and dived into it, leaving only his swimming trunks on. After swimming for some time among the predatory fish and without receiving any harm to his health, Herbert took fresh blood-soaked meat in his hand and continued to swim with it. But several dozen piranhas in the pool still did not approach the person, although quite recently they happily ate the same meat when there was no one in the pool.

Piranhas, considered fearsome predators with an insatiable thirst for fresh flesh, are actually quite timid fish and CARNARDERS, not daring to approach large creatures.

Moreover, experiments with piranhas have shown that when alone, these fish do not feel as calm as if they were surrounded by other fish.

But despite their peaceful behavior towards humans, piranhas are real killing machines for other fish species that are below them in the food chain. Their powerful jaws are designed to bite and tear, and their dense, muscular bodies are capable of incredibly fast movements and jerks underwater. The piranha's jaw muscle contraction force relative to body size is believed to be the highest of any other vertebrate in the world. For example, the common piranha can easily bite off the finger of an adult.

But in history there has not been a single reliable case of a fatal attack by piranhas on a person. But this does not mean at all that these fish never bite a person or an animal that enters the water. And this behavior is almost always caused not by the aggressive behavior of the fish, but by self-defense or abnormal weather conditions, because of which the behavior of the piranhas begins to differ sharply from usual. Abnormal weather conditions mean a period of drought, when the rivers in which piranhas live dry up, and many fish remain in depressions filled with water, but cut off from the main channel, deprived of food. Starving predators gradually begin to eat themselves and may well rush at any creature that comes close to the water. Sometimes the tendency of piranhas to behave aggressively is recorded during the spawning period, when they rush at a person or animal in self-defense, but such cases are extremely rare. And of course there is no talk of a collective attack by piranhas on humans.

Surprisingly, piranhas, being, according to many, one of the most the most dangerous predators, at the same time unusually timid! It is advisable to keep the aquarium in which piranhas live away from sources of noise and shadows, otherwise your pets will constantly be on the verge of fainting! It is a well-known fact among aquarists that a click on the glass or a sudden movement near the aquarium is enough for piranhas to faint. They also often faint during transportation from the place of purchase to their future home.

And here's Paku for you - common name several species of omnivorous South American freshwater piranhas. The pacu and the common piranha (Pygocentrus) have the same number of teeth, although differences in their alignment are noted; The piranha has pointed, razor-shaped teeth with a pronounced mesial bite (the lower jaw protrudes forward), while the pacu has square, straight teeth with a slight mesial or even distal bite (the upper front teeth are pushed forward in relation to the lower ones). As adults, wild pacu weigh more than 30 kg and are much larger than piranhas.

here's more about them -

27.04.2018
Over the past few years, astonished fishermen have pulled out not only tropical buffalo fish or no less exotic parrot fish from Russian seas, rivers and lakes, but more dangerous catches have been caught in their nets, such as barracuda, puffer fish and piranhas. Where did they come from in the Russian expanses?

Nadezhda Popova

The editor of Novye Izvestia reported about the amazing catch in the Tver province and Chief Editor newspaper "Voice of Udomlya", former mayor of the nuclear town Dmitry Podushkov. “In the cooling lake of our Kalinin nuclear power plant, an avid fisherman Igor Slivka caught a pacu fish, a type of piranha. We still can’t understand how the pacu ended up with us, in the Tver province?”

Indeed, a mystery!

But the real piranha was caught in Lake Ivan by experienced fisherman Ksenia Demina from the Trans-Baikal village of Tasei. There was no limit to surprise... Ksenia Demina sent a “portrait” of an outlandish fish to scientists at the Institute natural resources, ecology and cryology, Siberian Branch of the Russian Academy of Sciences. Ichthyologist and senior researcher at the institute Evgenia Gorlacheva concluded: this is indeed a piranha.

In Russia, piranhas have been caught in fishermen's nets for several years now. There is a known case when experienced fisherman Andrei Malyshev caught a piranha weighing more than 2 kg on Lake Sredny Kaban in Tatarstan. Piranha caught earthworm. But the fisherman with 40 years of experience was afraid to fry it. Malyshev took the catch to ichthyologists. Associate Professor, Department of Bioecology, Kazan University federal university, ichthyologist Rustem Saifullin confirmed that the caught fish was a piranha. But where did it come from in Lake Sredny Kaban? Go ahead. Resident injured in piranha attack Rostov region Grigory Kurilkin. While fishing in the Solenenky pit, he was attacked by a predator with sharp teeth when he went knee-deep into the water and cast his fishing rod. The fish grabbed Kurilkin's leg, tearing off a piece of meat. The wound turned out to be very deep, the piranha bit through the leg to the bone. These creepy little fish with razor-sharp teeth have already been pulled out of the Volga, Ob, Irtysh and Ishim. Two large piranhas were caught by amateur fishermen in the Belovo Reservoir in Kemerovo region. And there are more and more reports of unauthorized penetrations of bloodthirsty piranha into peaceful Russian water bodies. But the homeland of this fish is South America. Where did the piranha come from in Lake Ivan? And in Lake Sredny Kaban? Piranhas can gnaw the carcass of a large animal down to the skeleton in one minute. In 1981, in Obidus (Brazil), piranhas instantly tore to pieces 300 people: they found themselves in the water due to a shipwreck.

But not only piranhas began to climb into fishermen’s nets. Others, no less outlandish and very dangerous fish continue to float up in rivers and lakes of Russia. In the lower reaches of the Ob, fishermen almost caught a group of electric eels. This miracle of nature has strong electric charges and gives a discharge of 600-800 volts. But this electric fish lives in the rivers of Brazil and Colombia. How did electric eels get to the lower reaches of the Ob?

Near the Southern Kuril Islands, fishermen discovered an exotic half-meter sea snake living in subtropical waters. A tsutsik goby from the Sea of Marmara suddenly showed up in the cold Gulf of Finland. Crimea has its own surprises. Over the past few years, 25 new species have been discovered in the Black Sea sector of Crimea sea fish. Not long ago, in the bay of Sevastopol, fishermen caught a terrible ball fish with huge needles. The copy was delivered to scientists. The monster turned out to be poisonous fish fugu, which lives off the coast of Japan. Senior researcher at the Institute of Biology of the Southern Seas, Alexander Boltachev, believes that the appearance of the puffer fish, or pufferfish as it is also called, in the Sevastopol Bay is a mystery.

But she may have a clue.

“Such “aliens” usually end up in bodies of water containing ballast water from ships,” says Alexander Boltachev. – Sailors need ballast to increase the stability of ships at sea.

In the old days, stones, sand or cast iron could serve as ballast. But on modern ships Sea water serves as ballast. Huge tanks with a capacity of millions of liters are filled with a mixture of water and everything that the pumps have drawn in. It could be algae, silt, and yes - various Marine life. However, there is a procedure that should prevent the transfer of fauna: ballast water must be discharged at the entrance to the sea.

“But not every ship does this in good faith,” says Yulia Korniychuk, scientific secretary of the Institute of Biology of the South Seas. – Migration of fauna with ballast waters is very dangerous phenomenon. By the way, Vibrio cholerae was also brought from Asia to Latin America specifically with ballast water.

In the hands of Sevastopol ichthyologists in Lately Blue crab, tropical butterflyfish and Mediterranean barracuda were also caught.

Indeed, exotic fish and all sorts of little things end up in new environment habitats with ballast waters,” says hydrobiologist Mikhail Belykh. - Today main reason the spread of invaders is human activity. Canals in Russia and Europe began to be built back in the 19th century, connecting isolated rivers and reservoirs. The inhabitants of these reservoirs learned to travel across the seas and oceans. They are easily attached to the bottom of the ship and set sail. Previously, ichthyologists believed that a large number of uninvited guests would not take root in new “homes”: different water composition, different temperature, lack of usual spawning places. But it turned out that this is not so. The newcomers are settling very energetically. For example, on the Volga. In the early 1980s, the level of the Caspian Sea suddenly began to rise. The salinity level of the water has increased. And for many fish such water became suitable for life. And over the past few years average annual temperature the water in the river increased by 3 degrees. The former inhabitants of the Volga left to the north. And the inhabitants of the southern reservoirs immediately moved into their places. Otherwise, where did the largemouth buffalo fish come from in the Volga River basin - is it a North American chukuchan fish?

Real headache for nuclear Russia - zebra mussel, or zebra mussel. The bivalve mollusk, moving in its larval form in ballast water, demonstrates lightning-fast reproductive growth when the water is released. This zebra pollutes all available hard surfaces, altering the habitat, ecosystem and food chain. And it causes serious problems with contamination of hydraulic infrastructure. Marked high economic costs related to the cleaning of water intake pipeline systems and sluices. They especially suffer from zebra mussels in Russia nuclear power plants. In 2015, at the Kalinin nuclear power plant (in the cooling pond of which they caught the pacu fish, which we talked about at the very beginning), a zebra mussel surrounded the water supply system. Losses? Minus 20 million kWh. Almost all Russian nuclear power plants located in the European part of the country, to one degree or another, fall into the risk zone in this regard. The Baltic NPP, in particular, if it is finally included in the network, may also face such a problem in the future!

What else is interesting? Back in 2002, Russia, Iran and India signed an agreement on the creation of the North-South water transport route, which would connect the Baltic Sea with Persian Gulf through the Volga and Caspian Sea. A canal has already been dug through Iran, connecting the Caspian Sea with the Persian Gulf. Over the years, the North-South transport corridor has expanded greatly: now it is a multimodal network of sea (and other) transportation. And it united not only Russia, India, Iran, but also Afghanistan, Armenia and Azerbaijan. Baku joined the project quite recently. Now the corridor will go around the Suez Canal and will allow, for example, fruit to be delivered from Mumbai to St. Petersburg in just 14 days. Today, transportation takes 42 days. Who else will we start catching in our Oka and Dvina, as well as in Lake Ivan? Or rather, what are we already catching? dog shark, eyed knife, fish-stone? Or hairy monkfish, blob fish? God forbid you catch a redfin or a sunfish.

But what to do with uninvited migrants?

It appears that the situation may be improving after all, as the Ballast Water Management Convention came into force a few months ago. This happened in Nagoya (a major port city in Japan) at the Tenth Conference of the UN Convention on Biological Diversity.

And now there is hope that it will not only minimize the risk of invasion alien species through ballast water, says hydrobiologist Mikhail Belykh, but will also provide an international platform for international shipping, providing clear and reliable standards for the management of ships' ballast water. In accordance with its terms, shipowners must equip ships with systems to remove, neutralize, and prevent the intake or discharge of aquatic and pathogenic organisms in ballast water and sediments.

From the "NI" dossier.

Dog fish - also known as pufferfish, also known as puffer fish, also known as globefish, diodont, fahak, ball fish - is a deadly poisonous creature. Swims tail first. Its caviar, skin, and especially its liver contain tetrodotoxin, a nerve poison. Fugu poison is 25 times stronger than curare. One such “dog” can kill up to 40 people. In Japan, fugu is considered a delicacy. There is no antidote for fugu poisoning.

Piranha - subfamily freshwater fish the characin family, living in rivers and reservoirs South America. Large fish, olive-silver with a purple or red tint. Piranhas are capable of making various sounds. And when taken out of the water, they begin to bark or croak. The special structure of the powerful lower jaw and teeth allows the piranha to tear out large pieces of meat from its prey.

The electric eel is the most dangerous of all electric fish. In terms of the number of human victims, they are ahead of even piranhas. They can deliver powerful electrical shocks, which can cause heart failure. In areas where electric eels are found, local residents came up with a simple way to catch these fish. They are caught on... cows! Fishermen noticed that cows very easily endure electric shocks from snake-like fish, so they drive the cattle into a river with eels and wait until the cows stop mooing. The calmness of the herd is a signal that it is time to pull the eels out of the river: for a while they become safe - “de-energized”!

Based on materials from: newizv.ru

Piranha fish inspires horror not only in its native South America, but also in the inhabitants of all other continents. In terms of the number of myths, only a huge shark can be compared with a small river inhabitant.

She is the only one who can compete with her in bloodthirstiness and sharp teeth. And although the piranha is significantly smaller in size than the shark, this does not prevent it from freely ruling the South American rivers and lakes from Venezuela in the north to Argentina in the south.

Biological diversity

In total, ichthyologists count 9 genera, consisting of 58 species of piranhas. Only 25 species are predators, and the rest are herbivores. However, according to scientists, several thousand unknown species of characin fish (including piranhas) may live in the waters of hitherto unexplored areas of South America.

The largest types of piranhas

The most large species piranhas reach a length of half a meter and weigh 2.5 kg, and the smallest are only 25 cm and weigh 0.5 kg, but, regardless of size and color, all piranhas have teeth of amazing sharpness. Serrasalminae (Latin name for “toothies”) belong to the order Cyprinidae, family Characinidae, subfamily Sawtooth.

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Piranha teeth

Contrary to classification, piranha teeth do not resemble a saw, but rather a razor or sharply sharpened scissors. They have a triangular shape (the upper triangle fits into the groove between the lower ones) and reach 4-5 mm in length. These teeth aren't just a razor-sharp metaphor: Indians actually used them as razors in ancient times.

But piranha is not limited to sharp teeth alone. She has surprisingly powerful jaws. First, the jaws close and the teeth cut off what is in the mouth from everything else. Then the closed jaws move horizontally (that is, the piranha seems to be chewing), and its teeth, like electric razor knives, bite through harder materials, so that neither veins with bones, nor even thick sticks can resist the jaw!

Gastronomic delicacy

Residents of South America catch and enjoy eating piranhas, whose meat tastes like trout, although catching it is not so easy. To catch piranhas, they use huge hooks, which are used to catch huge fish weighing tens and hundreds of kilograms (and piranhas weigh only 0.5–2.5 kg) and thick fishing line. However, even after getting off the hook, the piranha will approach the bait again and again until it gets caught for dinner.

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Origin of the name: piranha

Piranha fish got its name from the word “pirusinha”. This is what the Topu Indians who lived in Brazil called it. “Piru” in their language means “fish”, and “sinya” means “teeth”, that is, “pirusinha” means “toothed fish”. The Portuguese who arrived in Brazil changed the name to the more familiar “piranha” or “piraya”, which translated means “pirate”.

In Germany and Russia, this fish received not at all menacing names: the Germans call this fish, round like a coin and covered with small shiny scales, “silver thaler”, and in our country it received the nickname “coin” or, depending on the size, “ruble” ", "kopeck piece" and so on. The Spaniards call this fish “cariba”, that is, “cannibal”, because, completely hungry, the piranha attacks its smaller comrades in the flock.

Unsurpassed survivability of piranhas

In general, it is common for piranhas to eat a piece of a friend. The barely grown fish (1.5–2 centimeters in length) are already tearing pieces of meat out of each other. At the same time, despite the sharpest teeth, it does not come to murder. A hungry piranha needs very little meat to satisfy its hunger, so taking a bite from its neighbor usually calms it down. And the victim soon recovers, because piranhas have amazing ability to regeneration, and bitten off pieces of meat grow back in them.