Electric eels do not use current. Electric eel: description and features. How do electric eels reproduce?

Electric eels (Electrophorus electricus) are the most dangerous of all electric fish existing in nature. If we take into account human casualties, they are ahead of even piranhas. These creatures can deliver powerful, repeated electrical shocks that can cause cardiac or respiratory failure. So it is better for a person to stay away from these amazing and dangerous creatures of nature. Based on this, it is not recommended to keep them in home aquariums. This is a very dangerous fish!

Electric eel: description

Electric eel looks very much like a snake. It has the same slippery skin, a long cylindrical body and a flattened head with a wide, square mouth. The fish does not have a dorsal fin; its long anal fin helps it swim well.

IN natural environment Electric eels can grow up to three meters in length and weigh forty kilograms. In an aquarium, fish of this species do not exceed one and a half meters in length. Females are noticeably larger than males.

The top color of the eel is dark green or grayish. The abdomen of the electric fish has a yellowish or orange tint. Young eels are olive-brown in color with yellow spots.

In the front part there are all the vital organs, which occupy only 20% of the entire body, the rest is a solid electrical organ, which consists of thousands of elements that reproduce electricity. This organ develops immediately after birth. If you touch a two-centimeter fry with your hand, you can already feel a slight tingling sensation. When the baby grows to 40 mm, the power will increase greatly.

Electric organs

The positive charge of the eel is in the front part of the body, the negative charge, respectively, in the back. In addition, the fish has an additional electrical organ that plays the role of a locator. It is the three electrical organs that distinguish this creature from other animals. They are connected to each other, this feature ensures that even the smallest discharge of an electric eel is powerful, since the charge is summed up. Eventually, it becomes so powerful that it can cause the death of anyone who encounters it.

Thanks to its electrical organs, the eel finds its prey like a radar. Apart from this, they are also used to communicate with each other. Especially during the breeding season, when the male makes loud, frequent calls and the female responds with longer calls.

When the eel is in a calm position and resting, no electricity comes from it, but when it conducts active image life, then an electric field is formed around.

Natural habitats

Electric eels are often found in Guiana, but are mainly found in the wild in the South American region in the Amazon and Orinoco river basins. Amazing creatures They love warm waters and prefer fresh, muddy bodies of water. Best places for electric fish these are bays, flats, swamps and floodplains.

Lifestyle

Electric eels remain incompletely studied to this day. For example, their life expectancy is wildlife never installed. At aquarium maintenance a female can live from 10 to 22 years, a male can live under the same conditions from 10 to 15 years.

As mentioned earlier, the hallmark of eels is their electrical organs. In addition, they have another amazing feature - they breathe air. This is necessary for them, since the respiratory mechanism of electric giants is very complex and is designed in such a way that fish need to regularly swim to the surface of the reservoir and inhale air. Thanks to this feature, eels can stay out of the reservoir for several hours.

The vision of fish is similar to giant snakes, they cannot boast, and are active mostly at night.

Electric eels are carnivorous and cannot be called vegetarians. Their diet includes fish, small birds, and amphibians. Sometimes these monsters of ponds can bite a small mammal. So they can safely be classified as predators.

Reproduction

Amazing details about these unusual creatures not all are listed yet. Electric eels multiply very in an interesting way. The male, using his saliva, builds a nest in which the female lays eggs. It’s simply amazing that from just one such clutch, about seventeen thousand small electric eels are born.

Newborn babies immediately eat the eggs that their mother lays after her firstborn. Electric eel babies remain close to their parent until they develop orientation organs.

What to use to catch an electric eel?

The eel, although electric, is still considered a fish, which means that it can be caught like any other when going fishing. But everything is not so simple - these creatures are deadly, so fishermen are not eager to have such a catch, despite the fact that eel meat is considered a delicacy.

In areas where electric eels are found in water bodies, local residents came up with a simple way to catch these dangerous fish. If you ask what you use to catch eels using the method invented by the aborigines, the answer will be very unusual - they catch them on cows! The thing is that cows are needed to take on the first powerful discharges of electricity. Fishermen noticed that cows, unlike all other living creatures, very easily endure electric shocks from snake-like fish, so livestock is simply driven into a river with eels and wait until the cows stop mooing and thrashing about in the water.

The calmness of the herd is a signal that it is time to drive them ashore and catch eels from the river with ordinary nets, which at that time become completely safe. After all, these monsters cannot emit current for a long time; each subsequent discharge is weaker than the previous one. In order to restore the power of the blows, the fish will need time. This is such unconventional fishing, but the catch is very unusual!

According to the results of experimental studies, it turned out that many fish can emit electrical discharges that can only be detected by special sensitive devices. Such discharges are important in the behavior of fish, especially schooling ones. But special electricity-generating organs capable of creating electric fields with noticeable voltage are noted in only about 250 species (according to Wikipedia). The electric eel is one of the few species that produces a very powerful discharge that can cause serious electric shock and even kill a person. These eels, just like electric catfish and eels, use this ability for hunting and protection from enemies.

The secret of electric eels and other features

The main secret behind the name electric eel is that these fish have nothing to do with real eels, except external resemblance thanks to the very long snake-like body shape. Scientific name This species is Electrophorus electricus. In the fish system, it is located in the order Gymnotiformes, which in old editions of the book “Animal Life” was a suborder of the order Cyprinidae. One of the 4 families in this group is the Electric eels, which includes singular gender with one view due to its exceptional uniqueness.

Area of ​​distribution and lifestyle

These heat-loving fish are common in the basins of large South American rivers (Orinoco and Amazon). They prefer shallow, low-flow or stagnant bodies of water overgrown with vegetation, often silted (lakes, oxbow lakes, ponds). The water in such reservoirs is usually cloudy and dirty.

Such conditions are characterized by a sharp lack of oxygen dissolved in water. Therefore, nature took care of the possibility of the eel obtaining additional oxygen from the atmospheric air.

For this purpose, in his oral cavity there are special areas of vascular tissue, penetrated big amount blood vessels that function like the epibranchial organ. In these areas, the blood is saturated with oxygen, that is, they act like lungs.

Breath

During the day, the electric eel usually lies at the bottom of its reservoir, but periodically rises to the surface of the water and, sticking its wide mouth out, draws in a certain amount of air. He does this quite noisily and immediately plunges under water again. Exhaled air exits through the gill slits. Thanks to this clearly audible breathing, the local natives can easily become aware of the presence of fish.

Swallow a new portion fresh air acne should be done at regular intervals of 15 minutes, but in reality they do it more often. Deprived of the opportunity to rise to the surface of the water for air, the eels die.

Provided that the oral cavity and body are kept moist unique fish The electric eel is capable of staying out of water for several hours without harming its health. This feature ensures their survival in those unfavorable conditions where they live.

Appearance and internal structure

Electrophorus electricus is very big fish, reaching a length of up to two and a half meters or even more. Heaviest weight– 20 kilograms. (Some sources give the figure 40 kilograms, but we rely on information from the fishbase website.) The usual length of adult fish is from 1 to 1.5 meters.

Description of appearance:

• The body is very long, rounded in cross-section behind the head and becoming compressed laterally in the tail.
• Half of the fins are missing - dorsal and ventral.
• The pectoral fins are very small, acting as stabilizers during movement.
• The anal fin is unusually developed. It is long: it has approximately 350 rays; starts almost immediately after pectoral fins(behind the anus) and extends to the tip of the tail.
• Thick skin covered with mucus, bare and devoid of scales, covers not only the body, but also the fins.
• The eyes appear very small relative to the body and are located closer to the top of the head, causing the visual focus to be directed upward. They are blue in color.
• The wide mouth is very large and contains small teeth arranged in two rows. Their task is limited only to firmly capturing and holding the prey. They are not suitable for chewing, so the eel swallows its food whole.

All these appearance features are very clearly visible in the photo of the electric eel.

Camouflage color and swimming methods

Electrophorus electricus has a typical camouflage body color: adult individuals are olive-brown with a brown tint, only the head below and in the area gill covers orange tint. The anal fin is colored the same as the entire body, only its edge may have a whitish edging. Young fish are slightly lighter in color with an ocher tint.

The main driver of this amazing fish is an unusually long anal fin covered with soft skin. Located along the entire belly, it slightly resembles the keel of a ship. It is aided by short pectoral fins.

Making wave-like movements with the anal fin and stabilizing the position of the body with the pectorals, it can swim straight or slightly arched. To the observer it looks incredibly beautiful. If necessary, the electric eel deftly and quickly changes the direction of its path without turning around with its entire body. It simply begins to swim backwards with its tail due to a change in the direction of the wave-like oscillation of its anal fin.

Generation of electrical discharges

The generation of electrical discharges of very high voltage is the main unique ability electric eels, which has been the subject of research by scientists for many years. It was possible to find out that the electric organ is a pair of oblong-shaped bodies located immediately under the thick skin and occupying 80% of the length of the entire body. They run along the entire spine, there are two pairs of them. As Brem writes in the book “Animal Life”, these formations are gelatinous in consistency in the form of a soft, translucent mass of reddish color. yellow color. Their weight is 30 percent of total weight fish.

A curious property of the mucus that abundantly covers the skin of the eel: its electrical conductivity is almost 30 times higher than that of clean water(from Brem’s book “The Life of Animals”).

In fact, the electric organ found in Electrophorus electricus is an original living battery, in which the “minus” corresponds to the back of the body, and the “plus” to the front. The electrical discharge generated by such a huge battery , can have a voltage of up to 600 volts and higher (in very large individuals), usually about 350 volts. Therefore, scientists classify the eel as a highly electric fish, and it ranks 1st on this list.

Based on the design of energy-generating bodies Electrophorus electricus, chemists and engineers (University of Michigan, USA) have created a biocompatible battery that is flexible enough for successful implantation into living organisms as a power source for motorized implants. The batteries offered so far have not been biocompatible.

The discharges created are used for several purposes: protection, hunting, orientation in space and notifying individuals of their species about their presence. Each goal is achieved with the help of discharges of various sizes - either weak or strong.

Nutrition and protection from enemies

Electric eels are predators that have almost no enemies in their natural environment. Juveniles eat invertebrates. Adults will eat anything Living being, which they can detect and grab. All aquatic inhabitants prefer not to approach them. Eels are a threat not only to the fish that form the basis of their diet, but also to lizards, turtles, frogs and even small mammals.

Only caimans pose a serious danger to the eels themselves. They cope with young and inexperienced caimans with the help of a good electric discharge, after receiving which the reptile retreats. But an adult large black caiman can sometimes catch and eat electric fish, remaining resistant to the resulting discharge.

In conditions of turbid and dirty water Where eels live, vision is not an important tool for obtaining information about what is around, or for finding food. Therefore, it is poorly developed in them, and as they grow older, as scientists suggest, it becomes worse.

Hunting using a remote shock

The electric eel employs a unique hunting strategy using its electrical discharges, which come in three types:

• Low-voltage impulses (to orient fish in the surrounding muddy water).
• A series of two or three short duration (fractions of milliseconds) high voltage pulses.
• Long-term sequence of high-voltage discharges.

These conclusions were made by zoologist Kenneth Catania (USA, Vanderbilt University) based on laboratory observations of electric eels kept in an aquarium with special equipment.

Hunting strategy

Eels hunt at night, and the hunting strategy consists of two stages:

• To detect hidden prey, they launch in all directions. short episode two or three high voltage pulses. The muscles of a fish that has received such a discharge begin to contract, and it twitches, causing the movement of its body to oscillate the water. This is enough for the eel; it immediately understands in which direction the prey is located and swims there.
• When directly attacking a detected victim, the electric eel sends a multi-voltage discharge (350 and up to 600 volts) towards it. high frequency, which immobilizes her. While the prey is paralyzed and the electric shock has not passed, the eel quickly grabs it and swallows it whole.

To immobilize prey detected with short high-voltage discharges, eels use remote electric shock, sending about 400 high-voltage pulses per second. They essentially control the muscles of their victims, commanding them to move or stop.

The electric eel is the only representative of the genus Electrophorus. The fish with the body of a snake is the same Electrophorus electricus. This fish lives in South America, preferring mainly the muddy waters of the Amazon and Orinoco. The electric eel is found in stagnant, shallow water with low oxygen levels.

Description of the electric eel

The electric eel has quite big sizes – average length the body is 2-2.5 meters, and some individuals reach 3 meters.

Electric eels weigh about 40 kilograms. The body shape is snake-like and the body is slightly compressed on the sides. The head is flat.

It is noteworthy that the electric eel completely lacks scales. The pectoral and caudal fins of the eel are very well developed; with their help, the fish swims well and can move in different directions. The color is camouflage gray-brown, it helps during hunting. The color of the head may differ from the general color and have an orange tint.

The unique feature of the electric eel

The name emphasizes the uniqueness of this fish; it is capable of generating electricity. The body of the electric eel is covered with special cells that are connected by nerve canals.

At the very beginning of the body the electrical discharge is weak, but towards the tail it becomes stronger. The electric eel's current is deadly not only for small fish, but also great opponents.

The power of the electrical impulse of this fish is on average 350 V. For people, such an electric shock is not fatal, but it can stun or cause loss of consciousness, so you should stay away from the electric eel.

The electric eel's mouth has unique vascular tissue, so it must sometimes rise to the surface to take a breath of air. It can remain on the surface for more than 10 minutes, while no other species of fish remains in the air for more than 30 seconds.

Electric eel hunting

This predator attacks suddenly; it does not give in even to large victims. If there is any living creature near the eel, it shakes its body, resulting in the formation of a charge with a power of 300-350 V, which instantly kills the prey located nearby, as a rule, this is a small fish.

When the paralyzed prey sinks to the bottom, the electric eel slowly approaches it and swallows it whole. After eating food, he rests for several minutes, digesting it.

Reproduction of electric eels

Very little is known about the reproduction of these fish. Scientists still don't fully know life cycle electric eel. It is known that at certain times eels swim away to hard-to-reach places, and they appear together with their grown-up offspring.

Some scientists believe that male electric eels make a nest out of saliva, and the female lays eggs in this nest. Approximately 17 thousand small fish emerge from one clutch. Individuals that are born first most often eat the rest of the eggs from the clutch.

Science does not know how the fertilization process occurs, where the young animals develop and what the babies eat. But it is clear that an electric eel with a body length of 10-12 centimeters is considered an adult.

Interesting facts about electric eels

The vision of these fish is extremely poor; it is believed that with age they are generally unable to see, and they are active mainly at night. They receive information about nearby obstacles using locators with low-frequency waves;
The electric eel has nothing in common with the common eel. The electric eel is a member of the class of ray-finned fish;
The electric eel has short teeth, so it does not chew its food, but swallows it completely;
Predatory eels eat not only small fish, but also amphibians, birds, crustaceans and small mammals;
With help electric charges individuals communicate with each other;
If you take a young electric eel, you can feel a slight tingling sensation;
Information about these fish first appeared in the 17th century. Then they were considered unknown creatures Antillean Sea. But 100 years later, Alexander von Humboldt made a description of the electric eel.

Life of electric eels in an aquarium

Unfortunately, the proximity of other eels and other types of fish will not work, since the neighbors are unlikely to be able to tolerate the electrical discharges emitted by the eel. When the eel is just swimming, it emits discharges with a power of 10-15 V, which act as electro-navigation, but when the prey approaches it, the signal power becomes much stronger.

Aeration is not necessary in the electric eel's home. The water temperature should not fall below 25 degrees, acidity is maintained within 7-8, and hardness 11-13 degrees. Electric eels do not tolerate frequent changes of water. It is believed that these fish create their own microclimate, accumulating antimicrobial substances that prevent them from getting sick, and if the water is changed too often, ulcers begin to develop on the surface of the eel’s body.

A sandy substrate is created at the bottom of the reservoir, and some pebbles are also allowed. The amount of vegetation in an electric eel aquarium should be moderate, and there should also be driftwood, rocks and caves.

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August 17, 2016 at 09:31 pm

Physics in the animal world: the electric eel and its “power station”

Electric eel (Source: youtube)

The fish species electric eel (Electrophorus electricus) is the only representative of the genus of electric eels (Electrophorus). It is found in a number of tributaries of the middle and lower reaches of the Amazon. The body size of the fish reaches 2.5 meters in length and weight - 20 kg. The electric eel feeds on fish, amphibians, and, if lucky, birds or small mammals. Scientists have been studying the electric eel for tens (if not hundreds) of years, but only now some structural features of its body and a number of organs have begun to become clear.

Moreover, the ability to generate electricity is not the only unusual feature of the electric eel. For example, he breathes atmospheric air. This is possible thanks to a large number special type tissue of the oral cavity, riddled with blood vessels. To breathe, the eel needs to swim to the surface every 15 minutes. It cannot take oxygen from water, since it lives in very muddy and shallow bodies of water, where there is very little oxygen. But, of course, the main one distinguishing feature electric eel - these are its electrical organs.

They play the role of not only a weapon for stunning or killing its victims, on which the eel feeds. The discharge generated by the electrical organs of the fish can be weak, up to 10 V. The eel generates such discharges for electrolocation. The fact is that fish have special “electroreceptors” that make it possible to detect distortions in the electric field caused by it. own body. Electrolocation helps the eel find its way through murky water and find hidden victims. The eel can give a strong discharge of electricity, and at this time the hidden fish or amphibian begins to twitch chaotically due to convulsions. The predator easily detects these vibrations and eats the prey. Thus, this fish is both electroreceptive and electrogenic.

It's interesting that the ranks different strengths The eel generates using three types of electrical organs. They occupy approximately 4/5 of the length of the fish. High voltages are produced by the Hunter and Men organs, and small currents for navigation and communication purposes are generated by the Sachs organ. Main body and Hunter's organ are located in the lower part of the eel's body, Sachs' organ is in the tail. Eels “communicate” with each other using electrical signals at a distance of up to seven meters. With a certain series of electrical discharges, they can attract other individuals of their species.

How does an electric eel generate electricity?

Eels of this species, like a number of other “electrified” fish, reproduce electricity in the same way as nerves and muscles in the bodies of other animals, only for this they use electrocytes - specialized cells. The task is performed using the enzyme Na-K-ATPase (by the way, the same enzyme is very important for mollusks of the genus Nautilus (lat. Nautilus)). Thanks to the enzyme, an ion pump is formed that pumps sodium ions out of the cell and pumps in potassium ions. Potassium is removed from cells thanks to special proteins that make up the membrane. They form a kind of “potassium channel” through which potassium ions are excreted. Positively charged ions accumulate inside the cell, and negatively charged ones accumulate outside. An electrical gradient arises.

The resulting potential difference reaches 70 mV. In the membrane of the same cell of the eel's electrical organ there are also sodium channels through which sodium ions can again enter the cell. Under normal conditions, in 1 second the pump removes about 200 sodium ions from the cell and simultaneously transfers approximately 130 potassium ions into the cell. A square micrometer of membrane can accommodate 100-200 such pumps. Usually these channels are closed, but if necessary they open. If this happens, the chemical potential gradient causes sodium ions to flow back into the cells. Happening overall change voltage from -70 to +60 mV, and the cell gives a discharge of 130 mV. The process duration is only 1 ms. Electric cells interconnect nerve fibers, the connection is serial. Electrocytes form peculiar columns that are connected in parallel. The total voltage of the generated electrical signal reaches 650 V, the current strength is 1A. According to some reports, the voltage can even reach 1000 V, and the current can reach 2A.

Electrocytes (electric cells) of an eel under a microscope

After the discharge, the ion pump operates again, and the eel's electrical organs are charged. According to some scientists, there are 7 types of ion channels in the membrane of electrocytic cells. The placement of these channels and the alternation of channel types affects the rate of electricity production.

Electric battery low

According to research by Kenneth Catania from Vanderbilt University (USA), the eel can use three types of discharge from its electrical organ. The first, as mentioned above, is a series of low-voltage pulses that serve for communication and navigation purposes.

The second is a sequence of 2-3 high-voltage pulses lasting several milliseconds. This method is used by eels when hunting hidden and hidden prey. As soon as 2-3 high voltage shocks are given, the muscles of the hidden victim begin to contract, and the eel can easily detect potential food.

The third method is a series of high-voltage, high-frequency discharges. The eel uses the third method when hunting, producing up to 400 pulses per second. This method paralyzes almost any small to medium-sized animal (even humans) at a distance of up to 3 meters.

Who else is capable of generating electric current?

About 250 species of fish are capable of this. For most, electricity is just a means of navigation, as, for example, in the case of the Nile elephant (Gnathonemus petersii).

But few fish are capable of generating an electric discharge of sensitive force. These are electric stingrays (a number of species), electric catfish and some others.

Electric catfish (

In mysterious and troubled waters The Amazon hides many dangers. One of them is the electric eel (lat. Electrophorus electricus) is the only representative of the order of electric eels. It is found in the northeast South America and is found in small tributaries of the middle as well as lower reaches of the powerful Amazon River.

The average length of an adult electric eel is one and a half meters, although sometimes three-meter specimens are found. This fish weighs about 40 kg. Her body is elongated and slightly flattened laterally. Actually, this eel doesn’t look much like a fish: it has no scales, only the caudal and pectoral fins, and on top of that, it breathes atmospheric air.

The fact is that the tributaries where the electric eel lives are too shallow and muddy, and the water in them is practically devoid of oxygen. Therefore, nature has endowed the animal with unique vascular tissues in the oral cavity, with the help of which the eel absorbs oxygen directly from the outside air. True, for this he has to rise to the surface every 15 minutes. But if the eel suddenly finds itself out of water, it can live for several hours, provided that its body and mouth do not dry out.

Electric coal is olive-brown in color, allowing it to remain undetected by potential mining. Only the throat and lower part of the head are bright orange, but this is unlikely to help the unfortunate victims of the electric eel. As soon as he shudders with his entire slippery body, a discharge is formed with a voltage of up to 650V (mostly 300-350V), which instantly kills all the small fish nearby. The prey falls to the bottom, and the predator picks it up, swallows it whole and anoints itself nearby to rest a little.

I wonder how he manages to generate such a powerful discharge? It’s just that his entire body is covered with special organs that consist of special cells. These cells are sequentially connected to each other using nerve canals. In the front of the body there is a “plus”, in the back there is a “minus”. Weak electricity is generated at the very beginning and, passing successively from organ to organ, it gains strength to strike as effectively as possible.

The electric eel itself believes that it is endowed reliable protection, therefore, is in no hurry to surrender even to a larger enemy. There have been cases when eels did not give in even to crocodiles, and people should avoid meeting them altogether. Of course, it is unlikely that the discharge will kill an adult, but the sensations from it will be more than unpleasant. In addition, there is a risk of loss of consciousness, and if you are in the water, you can easily drown.

The electric eel is very aggressive; it attacks immediately and is not going to warn anyone about its intentions. The safe distance from a meter-long eel is at least three meters - this should be enough to avoid dangerous current.

In addition to the main organs that generate electricity, the eel also has one more, with the help of which it scouts out its surroundings. This unique locator emits low-frequency waves, which, when returning, notify its owner about obstacles ahead or the presence of suitable living creatures.