And dangerous, lives in shallow muddy rivers of the northeastern part of the South American continent. It has nothing to do with ordinary eels, being a hymn-like fish. Its main feature is the ability to generate electric charges of various strengths and purposes, as well as detect electric fields.
Habitat
Over the millennia of evolution, electric eels have adapted to survive in the extremely unfavorable conditions of overgrown and silted water bodies. His habitual habitat is stagnant, warm and muddy fresh water with a large oxygen deficiency.
The eel breathes atmospheric air, so every quarter of an hour or more, it rises to the surface of the water to capture a portion of air. If you deprive him of this opportunity, he suffocates. But without any harm, acne can do without water for several hours if its body and mouth are moist.
Description
The electric eel has an elongated body, slightly compressed from the sides and back, rounded in front. The color of adults is greenish brown. The throat and lower part of the flattened head are bright orange in color. A characteristic feature is the absence of scales, the skin is covered with mucus.
The fish grows on average up to 1.5 m in length and weighs up to 20 kg, but there are also three-meter specimens. The absence of the pelvic and dorsal fin enhances the eel's similarity to a snake. It moves in undulating movements with the help of a large anal fin. It can equally easily move up and down, back and forth. Small pectoral fins act as stabilizers during movement.
Leads a solitary lifestyle. Spends most of the time at the bottom of the river, frozen among the thickets of algae. Eels are awake and hunt at night. They feed mainly on small fish, amphibians, crustaceans, and if you're lucky, birds and small animals. The victim is swallowed whole.
Unique feature
In fact, the ability to create electricity is not some extraordinary feature. Any living organism can do this to some extent. For example, our brains use electrical signals to control muscles. Eel produces electricity just like muscles and nerves in our body. Electrocyte cells store a charge of energy extracted from food. The synchronous generation of action potentials by them leads to the formation of short electrical discharges. As a result of the summation of thousands of tiny charges accumulated by each cell, a voltage of up to 650 V is created.
The eel emits electrical charges of various powers and purposes: impulses of protection, fishing, rest and search.
In a calm state, it lies on the bottom and does not generate any electrical signals. When hungry, it begins to swim slowly, emitting impulses with voltage up to 50 V with an approximate duration of 2 ms.
Having found prey, it sharply increases their frequency and amplitude: the intensity increases to 300-600 V, the duration is 0.6-2 ms. The pulse train consists of 50-400 discharges. The sent electrical discharges paralyze the victim. It uses high-frequency pulses to stun small fish, which the eel mainly feeds on. Pauses between discharges are used to restore energy.
When the immobilized victim sinks to the bottom, the eel calmly swims up to it and swallows it whole, and then rests for a while, digesting food.
Defending against enemies, the eel emits a series of rare high voltage pulses in the amount of 2 to 7, and 3 small search amplitudes.
Electrolocation
The electric organs of eels are not only for hunting and protection. They use weak discharges with a power of up to 10 V for electrolocation. The vision of these fish is weak, and worsens even more with old age. They receive information about the world around them from electrical sensors located throughout the body. In the photo of an electric eel, its receptors are clearly visible.
An electric field pulsates around a floating eel. As soon as an object, such as a fish, plant, stone, is in the field of action, the shape of the field changes.
Catching with special receptors the distortion of the electric field created by him, he finds a way and hiding prey in the muddy water. This hypersensitivity gives electric eel an advantage over other species of fish and animals that rely on sight, smell, hearing, touch, and taste.
Electric organs of acne
Discharges of different power are generated by organs of different types, occupying almost 4/5 of the length of the fish. In the front part of its body is the positive pole of the "battery", in the tail area - the negative one. The organs of Men and Hunter produce high voltage pulses. The discharges for communication and navigation functions are generated by the Sachs organ located in the tail. The distance at which individuals can communicate with each other is about 7 meters. To do this, they emit a series of discharges of a certain type.
The largest eels recorded in fish kept in aquariums reached 650 V. In fish of a meter in length, it is no more than 350 V. This power is enough to light five light bulbs.
How acne protects against electric shock
The voltage generated during hunting by electric eels reaches 300-600 V. It is fatal for small inhabitants like crabs, fish and frogs. Large animals such as caimans, tapirs and adult anacondas prefer to stay away from dangerous places. Why don't electric eels shock themselves?
Vital organs and heart) are located close to the head and are protected by fatty tissue, which acts as an insulator. Its skin has the same insulating properties. It has been noticed that damage to the skin increases the vulnerability of fish to electric shocks.
Another interesting fact has been recorded. During mating, eels generate very powerful discharges, but they do not cause damage to the partner. A discharge of such power, produced under normal conditions, and not during the mating period, can kill another individual. This indicates that acne has the ability to turn the electric shock protection system on and off.
Reproduction
Eels spawn with the onset of the dry season. Males and females find each other by sending impulses in the water. The male builds a well-hidden nest from saliva, where the female lays up to 1700 eggs. Both parents take care of the offspring.
The skin of the fry is of a light ocher hue, sometimes with marble streaks. The first hatched fry begin to eat the rest of the eggs. They feed on small invertebrates.
The electrical organs in fry begin to develop after birth, when their body length reaches 4 cm. Small larvae are capable of generating an electric current of several tens of millivolts. If you pick up a fry, which is only a few days old, you can feel tingling sensations from electrical discharges.
The juveniles that have grown up to 10-12 cm in length begin to lead an independent way of life.
Electric eels do well in captivity. The life span of males is 10-15 years, females - up to 22. How long they live in the natural environment is not known for certain.
The aquarium for keeping these fish should be at least 3 m long and 1.5-2 m deep. It is not recommended to change the water in it often. This leads to the appearance of ulcers on the body of the fish and their death. The mucus covering the skin of acne contains an antibiotic to prevent ulcers, and frequent water changes appear to reduce its concentration.
In relation to representatives of its own species, the eel, in the absence of sexual desire, shows aggression, therefore, only one individual can be kept in the aquarium. Water temperature is maintained at 25 degrees and above, hardness - 11-13 degrees, acidity - 7-8 pH.
Is acne dangerous for humans
Which electrical eel is especially dangerous to humans? It should be noted that a meeting with him is not fatal for a person, but it can lead to loss of consciousness. The electrical discharge from the eel leads to muscle contraction and painful numbness. The unpleasant sensation can last for several hours. In larger individuals, the current strength is greater, and the consequences of being hit by a discharge will be more deplorable.
This predatory fish attacks even a larger rival without warning. If an object falls within the range of its electric field, it does not float away and does not hide, preferring to attack first. Therefore, in no case should you approach a meter-long eel closer than 3 meters.
Although fish is a delicacy, catching it is deadly. Locals have invented an original way to catch electric eels. To do this, they use cows that tolerate electric shocks well. Fishermen drive a herd of animals into the water and wait for the cows to stop mooing and rushing about in fear. After that, they are driven out onto land, and they begin to catch harmless eels with nets. Electric eels cannot generate current indefinitely, and the discharges gradually become weaker and stop altogether.
Electric eel is a large fish with a length of 1 to 3 meters, the weight of an eel reaches 40 kg. The body of the eel is elongated - serpentine, covered with gray-green skin without scales, moreover, it is rounded in the front part, and flattened from the sides closer to the tail. Eels are found in South America, particularly in the Amazon Basin.
A large eel generates a discharge with a voltage of up to 1200 V and a current of up to 1 A. Even small aquarium individuals generate discharges from 300 to 650 V. Thus, an electric eel can pose a serious danger to humans.
The electric eel accumulates significant charges of electricity, the discharges of which are used for hunting and defense against predators. But the eel isn't the only fish that generates electricity.
Electric fish
In addition to electric eels, a large number of freshwater and saltwater fish are capable of generating electricity. In total, there are about three hundred such species from various unrelated families.
Most "electric" fish use an electric field to navigate or locate prey, but some have more serious charges.
Electric rays - cartilaginous fish, relatives of sharks, depending on the species, can have a charge voltage of 50 to 200 V, while the current reaches 30 A. Such a charge can hit rather large prey.
Electric catfish are freshwater fish, up to 1 meter in length, weighing less than 25 kg. Despite its relatively modest size, an electric catfish is capable of producing 350-450 V, with a current of 0.1-0.5 A.
Electrical organs
The aforementioned fish show unusual abilities thanks to the modified muscles - the electrical organ. In different fish, this formation has a different structure and size, and the location, for example, in an electric eel, it is located on both sides along the body and makes up about 25% of the fish's mass.
In Enoshima's Japanese aquarium, an electric eel is used to light up a Christmas tree. The tree is connected to the aquarium, the fish living in it produces about 800 watts of electricity, which is quite enough for illumination.
Any electrical organ consists of electrical plates - modified nerve and muscle cells, the membranes of which create a potential difference.
Electric plates, connected in series, are collected in columns, which are connected in parallel to each other. The potential difference generated by the plates is accumulated at opposite ends of the electric organ. It only remains to activate it.
An electric eel, for example, bends, and a series of electrical discharges passes between the positively charged front of the body and the negatively charged back, striking the victim.
First, here are some truthful facts about electric eels. Electric eel is not exactly an eel. The real eel is a long fish that looks a bit like a finned snake. The electric eel is a fish of the carp order, which resembles an eel only in shape (much like a balloon resembles a soccer ball). Unlike the harmless real eels, electric eels can be very traumatic for you.
The electric eel is one of 500 electric fish species, among which there are also electric catfish and electric stingray.
Why do they need electricity? Imagine that you are an electric eel (if you are a large specimen, then your length can reach 3 m and weight - 40 kg). The water in which you live is opaque, a huge amount of debris floats in it, so even during the day it is difficult to see anything in it.
How will you find your way through the dark murky water? Different animals have developed their own mechanisms for finding their way in the dark. Bats, for example, orient themselves by sending sound signals and listening to them reflecting off objects in their path. Electric eels, on the other hand, find their way in dark water using the electric fields generated by their own body, and this compensates for their poor vision.
The eel floats, and an electric field pulsates around it. The shape of the field changes when it stumbles upon some object that conducts current differently from water (for example, another fish, plant or stone), and special cells on the eel's body inform it about the violation of the field. Now it is clear why, even in the dark, the eel senses the objects around it.
This hypersensitivity gives the eel, like other electric fish, an advantage over other animals that have to rely on other senses: touch, taste, hearing, smell, and sight. For example, in one of the experiments, an electric fish without body contact in complete darkness found a thin glass rod 0.2 cm in diameter, which was hidden under a jar standing in water - it felt the fluctuations of its electric field, which penetrated the jar. In an electric eel, a special set of electrical organs is located along the entire length of the tail (the tail is 4/5 of the entire length of the eel, that is, 1-2 m). These organs are modified during muscle development.
Normal muscles, such as your biceps, contract with tiny electrical impulses of current. Originally, the muscles of the eel were intended for swimming in river water. But over the course of evolution, muscle fibers have transformed (now they cannot contract like our muscles) and adapted to generate electricity. They are not elongated in shape, like other muscle cells, but disc-shaped, resembling kitchen plates. These discs are lined with neurons at one end, like battery-powered bumps, and are arranged in rows one after the other. Each individual can have up to 700,000 of them. Even at rest, the eel constantly produces from 1 to 5 electrical low-voltage impulses per second. Irritate the eel - and the pulse rate will rise to 20-50 per second.
Why did electrical organs evolve? In addition to performing the function of recognizing invisible objects in turbid water, electric organs also serve as a weapon for the eel. The eel uses powerful discharges to stun or even kill prey, such as fish that have swum within the range of its electric field. In addition, the electric organs are a kind of electric fence, which scares off predatory animals that had the imprudence to covet and taste it. An irritated eel can produce over 500 volts of power at 1 amp - enough to make a person pass out and a room full of light bulbs to briefly light up.
Dominic Statham
Photo © depositphotos.com / Yourth2007
Electrophorus electricus) lives in the dark waters of swamps and rivers in northern South America. It is a mysterious predator with a sophisticated electro-location system and is able to move and hunt in low visibility conditions. By using "electroreceptors" to detect electrical field distortions caused by his own body, he is able to detect a potential victim without being noticed himself. It immobilizes the victim with a powerful electric shock, strong enough to stun a large mammal such as a horse, or even kill a person. With its elongated, rounded body shape, the eel resembles the fish that we usually call moray eels (order Anguilliformes); however, it belongs to a different order of fish (Gymnotiformes).Fish capable of detecting electric fields are called electroreceptive, and those capable of generating a powerful electric field, such as an electric eel, are called electrogenic.
How does an electric eel generate such a high electrical voltage?
Electric fish are not the only ones capable of generating electricity. In fact, all living organisms do this to one degree or another. The muscles in our body, for example, are controlled by the brain using electrical signals. The electrons produced by bacteria can be used to generate electricity in fuel cells called electrocytes. (see table below). Although each cell carries a negligible charge, due to the fact that thousands of such cells are assembled in series, like batteries in a flashlight, voltages of up to 650 volts (V) can be generated. If you arrange these rows in parallel, you can get an electric current of 1 Ampere (A), which gives an electric shock of 650 watts (W; 1 W = 1 V × 1 A).
How does an eel manage not to shock itself with an electric shock?
Photo: CC-BY-SA Steven Walling via Wikipedia
Scientists don't know exactly how to answer this question, but some interesting observations may shed light on the problem. First, the vital organs of the eel (such as the brain and heart) are located near the head, away from the organs that generate electricity, and surrounded by fatty tissue, which can act as insulation. Skin also has insulating properties, as it has been observed that acne with damaged skin is more susceptible to self-muffling by electrical shock.
Secondly, eels are capable of inflicting the most powerful electrical shocks at the time of mating, without harming the partner. However, hitting another eel with the same force outside of mating can kill it. This suggests that acne has some kind of defense system that can be turned on and off.
Could electric eel evolve?
It is very difficult to imagine how this could happen in the course of minor changes, as required by the process proposed by Darwin. In case the shockwave was important from the very beginning, then instead of stunning, it would warn the victim of danger. Moreover, in the course of evolution to develop the ability to stun a victim, an electric eel would have to simultaneously develop a self-defense system. Each time there was a mutation that increased the force of the electric shock, another mutation must have occurred that would improve the electrical insulation of the eel. It seems unlikely that one mutation would be enough. For example, in order to move organs closer to the head, it would take a whole series of mutations that would have to occur simultaneously.
Although few fish are capable of stunning their prey, there are many species that use low voltage electricity for navigation and communication. Electric eels belong to a group of South American fish known as "knife-tails" (family Mormyridae), which also use electrolocation and are believed to have developed this ability along with their South American counterparts. Moreover, evolutionists are forced to claim that the electrical organs in fish evolved independently eight times... Considering the complexity of their structure, it is striking that these systems could have evolved in the course of evolution at least once, not to mention eight.
Knife wheels from South America and chimera from Africa use their electrical organs for location and communication, and use a number of different types of electroreceptors. In both groups there are species that produce electric fields of various complex waveforms. Two types of knives, Brachyhypopomus benetti and Brachyhypopomus walteri so similar to each other that they could be attributed to the same type, however, the first of them produces a constant voltage current, and the second - an alternating voltage current. Evolutionary history becomes even more remarkable when you dig even deeper. In order to prevent their electrolocation devices from interfering with each other and not interfering, some species use a special system, with the help of which each of the fish changes the frequency of the electric discharge. It is noteworthy that this system works in almost the same way (the same computational algorithm is used) as that of a glass knife from South America ( Eigenmannia) and African fish aba aba ( Gymnarchus). Could such a system for eliminating interference have evolved independently in the course of evolution in two separate groups of fish living on different continents?
A masterpiece of God's creation
The power unit of the electric eel has eclipsed all human creations with its compactness, flexibility, mobility, environmental safety and the ability to self-heal. All parts of this apparatus are perfectly integrated into the polished body, which gives the eel the ability to swim with great speed and agility. All the details of its structure - from tiny cells that generate electricity to the most complex computing complex that analyzes the distortions of electric fields produced by eels - indicate the design of the great Creator.
How does an electric eel generate electricity? (popular science article)
Electric fish generate electricity just like the nerves and muscles in our body do. Inside the electrocyte cells, there are special enzyme proteins called Na-K AT Phase pump out sodium ions through the cell membrane, and suck up potassium ions. ('Na' is the chemical symbol for sodium, and 'K' is the chemical symbol for potassium. " An imbalance between potassium ions inside and outside the cell creates a chemical gradient that pushes the potassium ions out of the cell again. Likewise, an imbalance between sodium ions creates a chemical gradient that pulls sodium ions back into the cell. Other proteins embedded in the membrane act as channels for potassium ions, pores that allow potassium ions to leave the cell. As potassium ions with a positive charge accumulate outside the cell, an electrical gradient builds up around the cell membrane, with the outside of the cell having a more positive charge than the inside. Pumps Na-K ATPase (sodium potassium adenosine triphosphatase) are constructed in such a way that they select only one positively charged ion, otherwise negatively charged ions would also flow over, neutralizing the charge.
Most of the body of an electric eel is made up of electrical organs. Hunter's main organ and organ is responsible for generating and storing electrical charge. The Sachs organ generates a low voltage electric field that is used for electro-location.
The chemical gradient acts to push the potassium ions out, and the electrical gradient pulls them back in. At the moment of balance, when chemical and electrical forces cancel each other out, there will be about 70 millivolts more positive charge outside the cell than inside. Thus, there is a negative charge of -70 millivolts inside the cell.
However, more proteins built into the cell membrane provide channels for sodium ions - these are the pores that allow sodium ions to enter the cell again. In the normal state, these pores are closed, but when the electrical organs are activated, the pores open, and sodium ions with a positive charge enter the cell again under the influence of the chemical potential gradient. In this case, balance is achieved when a positive charge of up to 60 millivolts is collected inside the cell. There is a total voltage change from -70 to +60 millivolts, and this is 130 mV or 0.13 V. This discharge occurs very quickly, in about one millisecond. And since about 5000 electrocytes are collected in a series of cells, thanks to the synchronous discharge of all cells, up to 650 volts can be generated (5000 × 0.13 V = 650).
Na-K ATPase (sodium-potassium adenazine triphosphatase) pump. During each cycle, two potassium ions (K +) enter the cell, and three sodium ions (Na +) leave the cell. This process is driven by the energy of the ATP molecules.
Glossary
An atom or molecule that carries an electrical charge due to an unequal number of electrons and protons. An ion will have a negative charge if it contains more electrons than protons, and a positive charge if it contains more protons than electrons. Potassium (K +) and sodium (Na +) ions have a positive charge.
Gradient
Change of any value when moving from one point in space to another. For example, if you move away from a fire, the temperature drops. Thus, the fire generates a temperature gradient that decreases with distance.
Electric Gradient
The gradient of the change in the magnitude of the electric charge. For example, if there are more positively charged ions outside the cell than inside the cell, an electrical gradient will flow across the cell membrane. Due to the fact that the same charges are repelled from each other, the ions will move in such a way as to balance the charge inside and outside the cell. The movement of ions due to the electrical gradient occurs passively, under the influence of electrical potential energy, and not actively, under the influence of energy coming from an external source, for example, from an ATP molecule.
Chemical gradient
Chemical concentration gradient. For example, if there are more sodium ions outside the cell than inside the cell, then the sodium ion chemical gradient will pass through the cell membrane. Due to the random movement of ions and collisions between them, there is a tendency that sodium ions will move from higher concentrations to lower concentrations until a balance is established, that is, until there are an equal number of sodium ions on both sides of the membrane. This happens passively as a result of diffusion. The movements are driven by the kinetic energy of the ions, not energy derived from an external source such as an ATP molecule.
Talk about electric fish. How much current do they generate?
Electric catfish.
Electric eel.
Electric Stingray.
V. Kumushkin (Petrozavodsk).
Among the electric fish, the first place belongs to the electric eel, which lives in tributaries of the Amazon and other rivers of South America. Adult eels reach two and a half meters. The electrical organs - the transformed muscles - are located on the sides of the eel, extending along the spine for 80 percent of the entire length of the fish. This is a kind of battery, the plus of which is in the front of the body, and the minus in the back. A living battery generates a voltage of about 350, and in the largest individuals - up to 650 volts. With an instantaneous current strength of up to 1-2 amperes, such a discharge can knock a person off his feet. With the help of electrical discharges, the eel defends itself from enemies and obtains food for itself.
Another fish lives in the rivers of Equatorial Africa - the electric catfish. Its dimensions are smaller - from 60 to 100 cm. Special glands that generate electricity make up about 25 percent of the total weight of the fish. The electric current reaches 360 volts. There are known cases of electric shock in people bathing in the river and accidentally stepping on such a catfish. If an electric catfish falls on a fishing rod, then the angler can receive a very noticeable shock by the current that passed along the wet fishing line and the rod to his hand.
However, skillfully directed electrical discharges can be used medicinally. It is known that the electric catfish occupied an honorable place in the arsenal of traditional medicine among the ancient Egyptians.
Electric rays are also capable of generating very significant electrical energy. There are more than 30 types of them. These sedentary bottom dwellers, ranging in size from 15 to 180 cm, are distributed mainly in the coastal zone of tropical and subtropical waters of all oceans. Hidden at the bottom, sometimes half immersed in sand or silt, they paralyze their prey (other fish) with a discharge of current, the voltage of which varies from 8 to 220 volts for different types of rays. A stingray can also inflict a significant electric shock on a person who accidentally comes into contact with it.
In addition to electric charges of great strength, fish are also capable of producing low-voltage, weak current. Thanks to the rhythmic discharges of a weak current with a frequency of 1 to 2000 pulses per second, they are perfectly oriented even in muddy water and signal to each other about the emerging danger. Such are the mormiruses and gymnarchs who live in the murky waters of rivers, lakes and swamps in Africa.
In general, as experimental studies have shown, practically all fish, both marine and freshwater, are capable of emitting very weak electrical discharges, which can be detected only with the help of special devices. These discharges play an important role in the behavioral reactions of fish, especially those that constantly keep in large schools.
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