Electric eel - a mysterious and dangerous fish , lives in shallow muddy rivers of the north-eastern part of the South American continent. He has nothing to do with ordinary eels, being an anthem-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 extremely adverse conditions of overgrown and silted reservoirs. The habitat habitual for it is stagnant, warm and muddy fresh water with a large oxygen deficiency.
Eel breathes atmospheric air, so every quarter hour or more often it rises to the surface of the water to capture a portion of air. If you deprive him of this opportunity, he will suffocate. But without any harm, acne can do without water for several hours if its body and oral cavity are moistened.
Description
An 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. A characteristic feature is the absence of scales, the skin is covered with mucus.
Fish grows to an average of 1.5 m in length and weighs up to 20 kg, but three-meter specimens are also found. The absence of an abdominal and dorsal fin enhances the resemblance of an eel 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, when moving, serve as stabilizers.
Leads a solitary lifestyle. Spends most of the time at the bottom of the river, freezing among thickets of algae. The 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 unusual feature. Any living organism can do this to some extent. For example, our brain controls muscles through electrical signals. Eel produces electricity just like muscles and nerves in our body. Electrocyte cells accumulate 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.
Eel emits electric charges of various power and purpose: impulses of protection, fishing, rest and search.
In a calm state, it lies at the bottom and does not generate any electrical signals. Hungry, he begins to swim slowly, emitting pulses of voltage up to 50 V with an approximate duration of 2 ms.
Having discovered the prey, it sharply increases their frequency and amplitude: the intensity increases to 300-600 V, the duration is 0.6-2 ms. A series of pulses consists of 50-400 bits. Sent electrical discharges paralyze the victim. To stun small fish, which eel mainly feeds on, it uses high-frequency pulses. 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 the whole, and then rests for a while, digesting food.
Defending itself from enemies, eel emits a series of rare high-voltage impulses in an amount of 2 to 7, and 3 small search amplitudes.
Electrolocation
The electric organs of eels are not only for hunting and protection. Weak discharges with a power of up to 10 V are used for electrolocation. The vision of these fish is weak, and by old age it is even worse. They receive information about the world from electric sensors located throughout the body. In the photo of electric eel, its receptors are clearly visible.
Around the floating eel, an electric field pulsates. As soon as an object appears in the field of action of the field, for example, a fish, plant, stone, the shape of the field changes.
By catching the distortions of the electric field created by him with special receptors, he finds a path and hiding prey in muddy water. Such hypersensitivity gives electric eel an advantage over other species of fish and animals that rely on eyesight, smell, hearing, touch, taste.
Electrical organs blackheads
Discharges of various capacities are generated by organs of various types, occupying almost 4/5 of the length of the fish. In the front of his body is the positive pole of the "battery", in the tail region - the negative. The organs of Men and Hunter produce high voltage pulses. The discharges for the implementation of communication and navigation functions are generated by the Saks 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 discharge of electric eels recorded in the fish contained in the aquariums reached 650 V. In fish of a meter length, it is no more than 350 V. Such power is enough to light five light bulbs.
How acne is protected from electric shock
The voltage generated during hunting by electric eel reaches 300-600 V. It is deadly for small inhabitants like crabs, fish and frogs. And large animals, such as caimans, tapirs and adult anacondas, prefer to stay away from dangerous places. Why don't electric eels shock themselves?
The vital organs of the fish (brain and heart) are located close to the head and are protected by adipose tissue, which acts as an insulator. His skin has the same insulating properties. It is noticed that when the skin is damaged, the vulnerability of fish to electric shock increases.
Another interesting fact was recorded. During pairing, blackheads generate very powerful discharges, but they do not cause damage to the partner. A discharge of such power, produced under ordinary conditions, and not during the mating period, can kill another individual. This indicates that acne has the ability to turn on and off the protection system against electric shock.
Breeding
Acne spawns with the onset of the dry season. Males and females find each other, 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 a light ocher shade, sometimes with marble stains. The first hatched fry begin to eat the rest of the eggs. They feed on small invertebrates.
Electric organs in fry begin to develop after birth, when their body length reaches 4 cm. Small larvae are able to generate 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 from electrical discharges.
Grown up to 10-12 cm in length, juveniles begin to lead an independent lifestyle.
Captivity
Electric eels feel good in captivity. The life expectancy of males is 10-15 years, females - up to 22. How much 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. Water in it is often not recommended. This leads to the appearance of ulcers on the body of fish and their death. The mucus covering the skin of the blackheads contains an antibiotic that prevents the appearance of ulcers, and the frequent change of water, apparently, leads to a decrease in its concentration.
In relation to representatives of its species, eel, in the absence of sexual desire, is aggressive, therefore, only one individual can be kept in the aquarium. Water temperature is maintained at 25 degrees and above, hardness is 11-13 degrees, acidity is 7-8 pH.
Is eel dangerous for humans?
What electrical acne is especially dangerous for humans? It should be noted that for a person meeting with him is not fatal, but can lead to loss of consciousness. Electric discharge of eel leads to contraction and painful numbness of the muscles. An unpleasant sensation can last several hours. Larger individuals have more amperage, and the consequences of a discharge will be worse.
This predatory fish attacks without warning even a larger rival. If an object falls within the radius of its electric field, it does not float away and does not hide, preferring to attack first. Therefore, closer to meter eel closer than 3 meters, in no case impossible.
Although fish is a delicacy, fishing is deadly. Locals invented an original way to catch electric eels. To do this, they use cows that tolerate electric shock. Anglers drive a herd of animals into the water and wait for the cows to stop screaming and rushing about in fright. After that, they are driven out to land, and they begin to catch already harmless eels in nets. Electric acne cannot endlessly generate current, and discharges gradually become weaker and completely cease.