Electric eels are large fish found throughout South America that can produce up to 600 volts of electricity. The electricity is produced through specialized organs that make up the majority of their body. Electricity is very important in their day to day lives. They use this power to hunt in murky water, defend themselves, navigate as well as communicate with other eels around them.
There aren’t many animals that have defense mechanisms as unique as the electric eel. After all, there are so many questions. How do the eels produce their electricity? How can they shock other animals without shocking themselves? And, if you were ever to come in contact with an electric eel, do they have enough power to kill you?
What Are Electric Eels?
Electric eels, or Electrophorus electricus, are a type of carnivorous freshwater fish. They can grow quite large with a total body length of 6-8 ft (1.8-2.4 m), and a weight of up to 44 pds (20 kg). They are fairly long-lived fish with a lifespan of up to 15 years.
The interesting thing about electric eels is that, despite their name, they’re not actually eels. They are more genetically related to carp and catfish species than they are to true eels. However, they were given the name of “eel” simply because their body shape so closely resembles that of eels.
Their bodies are very similar to eels because they are long and cylindrical. Their body length can reach up to 8 ft (2.4 m) in length.
Their heads are much flatter than their round bodies. The coloration of their dorsal side is usually dark green or gray, with a lighter yellowish color covering their underside. They do not have scales, and their bodies are completely smooth.
They Aren’t True Eels
Although they look a lot like true eels, they lack the characteristics that would classify it as an eel. True eels are part of the order Anguilliformes, while the electric eel is part of the order Gymnotiformes, or the knife fishes.
They have no pelvic or dorsal fins. Instead, they have a small caudal fin. They also have a very long anal fin that travels down their body and helps them to swim. The anal fin is so helpful that the fish can not only swim forward, but it can swim backward, and even hover.
To be considered a true eel, an animal must have a long dorsal fin that combines with the anal and caudel fin. Electric eels lack this dorsal fin, and their anal and caudal fin are separate.
organ of an electric eel
The inside of an electric eel’s body is interesting as well because the majority of its body consists of just three organs. Its main electrical organ as well as the Hunter’s organ and the Sachs’ organ fill up 80% of the fish’s body cavity. The rest of its organs are compacted in the front of the body.
Obligate Air Breathers
They are freshwater fish and need to stay in the water to survive. However, they breathe air as well as water, so they frequently surface for air. The fact that they are able to breathe air from the surface of the water is vitally important as the seasons change.
There are distinct wet and dry seasons where electric eels reside. During the rainy season, the fish are golden. The water swells, and the lakes will become connected to rivers so that the eels have more space to spread out.
However, as the dry season moves in, the connections dry out and there is much less water for the fish to inhabit. Many electric eels will be crammed into the same area. This causes a quick depletion of the oxygen in the already poorly-oxygenated water.
When they swim to the surface of the water, they use their highly vascularized folds to breathe air. These folds have a lot of surface area so that the fish can easily take up air. They have a special mucous membrane inside their mouth that allows them to absorb oxygen from the air.
Electric Eels Habitat
These fish can be found in streams, rivers, and ponds in South America. They live in waters all across Brazil, and also inhabit the Guianas, Venezuela, Suriname, Peru, and Ecuador. You can find them primarily in the Amazon and Orinoco basins. They prefer slow-moving waters where it is easier for them to swim.
Reproduction & Development
Electric eels will breed during the dry season, and a single female eel can produce between 1,200-1,700 eggs. Before the eggs are laid, the male will get to work creating a nest. He will create the nest with his own saliva. After the eggs are deposited, the male will stand guard over the eggs until the rainy season begins.
Electric eels are carnivorous and feed mostly on fish, but they are known to eat types of amphibians, birds, and small mammals as well. Juveniles will feed mostly on invertebrates. Newly hatched electric eels are cannibalistic as they will eat the remaining eggs which have not hatched yet.
Electric eels are at the top of the food chain, so they are not at high risk of predation. There are very few animals who would be large or skilled enough to try and kill an electric eel. For example, an electric eel is even capable of taking down a large caiman.
Eels are listed as “least concern” on the IUCN Red List. They are abundant fish throughout their natural area, but people are still not allowed to capture them without a scientific permit.
Some areas of the world do not allow electric eels to be kept as pets either because they pose a threat to local fish and human populations. Unfortunately, some people will release their pets into the wild when they are no longer wanted, and it can wreak havoc on the local populations.
However, there are several places where you can purchase an electric eel as a pet, including certain states in the United States.
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How Do Electric Eels Produce Electricity
The thing that electric eels are known for, of course, is their ability to produce electricity. This makes them formidable predators, and they can be a danger even to humans.
How Much Electricity Do They Produce?
Electric eels have evolved the ability to produce electricity because it is a mechanism of protection as well as a way to catch their prey.
Even when it is not actively hunting something, an electric eel will produce a constant stream of electricity. They will consistently emit electricity in pulses of about 10 volts because it acts as a type of radar. The waters they live in tend to be very muddy and murky, so they can’t see very well. The electric currents they produce act as a type of radar to help them get around.
When on the hunt, an electric eel can produce up to 600 volts of electricity. They do not produce a constant stream of electricity similar to how a power line would. Instead, they emit pulses of electricity in short bursts that usually last about 2 msec.
Hunting is difficult for electric eels because the waters are typically dark and murky. They utilize small hairs along their body that are able to detect motion through pressure change.
If the fish senses that there is prey nearby, it will emit what is called a doublet, or two rapid electrical pulses. The doublet will cause muscle contractions in the prey which causes it to thrash about in the water. When the eel feels this movement, they know for sure that they’re in close proximity to a source of prey. It will then emit a larger shock that paralyzes the prey.
Also, water is an effective electrical conductor, so the fish can shock over a larger surface area. However, this can also be a disadvantage for the fish because it means that the shock won’t be as strong. When electricity is applied across a larger surface area, the shock won’t be as strong.
To combat this disadvantage, electric eels will jump out of the water to shock their predators or prey. When shocked in the air rather than the water, the electrical shock is far more concentrated, becoming significantly more painful and lethal.
Electric eels will take advantage of this ability whenever they’re able. For this to work, the predator or prey needs to be partially out of the water. The fish will jump onto the part of the animal that is exposed so that they can target the perfect area to attack. As they shock their target, they will emit shocks that become increasingly more powerful.
Where Do They Get Their Electricity?
But, how do electric eels come up with this energy?
Electric eels have about 6,000 muscle cells within their body that each produce a small amount of current. When you add up thousands of cells producing a small current, you get one large, dangerous surge of current.
They have specialized organs capable of producing both weak and stronger charges. The electrical organ is the main organ utilized, but the Hunter’s organ and the Sachs’ organ are also used. These organs are most commonly used for hunting, but the fish also use them for navigation, communication, and defense.
When an electric eel wants to produce a weaker electric shock, they utilize about ⅓ of their Hunter’s organ, as well as their Sachs’ organ to produce the current.
When they need to produce a more lethal shock, they will utilize the main ⅔ of the Hunter’s organ as well as the main electrical organ. They avoid producing these stronger electrical currents whenever possible because it quickly drains them of energy.
These electrical cells are shaped like a disc, and they are all packed into the electric producing organs within the fish. The nervous system operates these organs and cells, deciding when they are to be fired off.
When the fish needs to produce an electric current, the nervous system will fire all 6,000 cells at once to generate one forceful surge of electricity. This works through a “command nucleus” which is in charge of all the cells. The “command nucleus” will emit the signal to produce electricity, and a complex system of nerves will force all of the cells to fire at once.
These cells act similarly to batteries in an appliance. A negative charge is carried on the outside of the cell. When the command to produce electricity goes out, the inside and the outside of the cell connect to create a path.
In this way, a cell is able to behave as an activator to the other cells around it. The neighbor cells activate all of the cells surrounding them, creating one big reaction that occurs in just 2 msec.
Why Don’t Electric Eels Electrocute Themselves?
Electric eels hunt by shocking their prey, delivering a fatal shock. How then, do they not shock themselves when they produce this powerful surge of electricity?
Honestly, researchers aren’t quite sure about the answer to this yet. One theory suggests that electric eels likely feel the shock, but their body is so resistant to the electricity that it does not cause any damage.
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Can Electric Eels Kill Human
The electricity that an electric eels produces can equal up to 600 volts of electricity. But, is that enough to kill a human?
How Much Is 600 Volts, Really?
To give you some perspective, a typical electric fence will range in voltage of 2,000-10,000 volts depending on if you’re housing dogs, horses, cows, or sheep. If you’ve ever felt a shock from an electric fence, then you know that it hurts, but it’s not going to kill you. We wouldn’t keep our animals within these fences if they had the potential to kill.
Conversely, a bolt of lightning can have anywhere from 100 million to 1 billion volts of electricity. Most lightning strikes are fatal, of course, but there are still people who survive them. How is this possible?
The lowest recorded voltage known to have killed a human was just 42 volts. With this in mind, you’d think it right to assume that an electric eel and an electric fence are both more than enough to kill a human.
High Voltage Might Not Be Enough To Kill You
However, there are several factors that play a part in determining a fatal shock for a human. The reality is, the voltage actually plays a fairly small part in this. The factors that play a part in the lethal nature of a shock usually include a combination of voltage, amperage, the surface area exposed to the shock, and the amount of time exposed to the shock.
The reality is, that in some cases, 10,000 volts of electricity can be less dangerous than 100 volts. This is because the current is far more important than the voltage.
Current Is More Dangerous Than Voltage
Generally, higher voltage is more dangerous because it’s more likely to draw a larger current, but this is not always the case. The reality is, that it is the current that makes the fatal strike, but the voltage makes the current possible.
What exactly is current that makes it so dangerous? Current is the movement of electrons through a material. The electrons will move from the point of highest potential to the area with lowest potential.
Electrical wires are designed so that one end has high potential, and the other end has low potential. This makes it easy for the electrons to travel through the wire.
Electrons also prefer to travel in the direction with least resistance, which is usually the wire. For you to become electrocuted, your body needs to have less resistance than whatever else is in the curren’ts path.
The Path Of Least Resistance
Think of it this way: it is the same reason that birds can perch on electrical wires without being electrocuted. Birds are sitting in the way of these electric currents, but their body acts as a form of higher resistance than the wire, so the current bypasses the birds and continues to travel through the wire. It is simply easier for the current to travel through the wire than the bird’s body.
In the same way, if a human were to hang off a power line, they most likely would not be electrocuted. The power line is still the path of least resistance, so the electricity would bypass the human’s body and continue through the line.
However, if the human were to touch the ground while also touching the power line, they will be electrocuted. Touching the ground gives the electricity a path that now has less resistance than what is found in the power line.
How Much Current Can Really Kill A Human?
Voltage still plays a huge part in electrocution because it drives the current, but all-in-all, the current is what kills you. Theoretically, a current of only 10 mA is potentially enough to kill us because our hearts have low resistance.
However, the resistance of our skin is much higher, so it absorbs a current of 10 mA before it ever has a chance to reach our heart. Even a current of 100 mA is not usually enough to kill a human, although it will begin to cause muscle contractions.
When a current of 1,000 mA is reached, our muscle contractions become so bad that we are no longer able to release the wire. This is where the time factor comes in.
If a person is exposed to 1,000 mA of current for an extended period of time, it will lead to muscle paralysis. This, in turn, leads to ventricular fibrillation in the heart which can lead to death if the wire is not released.
If a person is exposed to a current of 2,000 mA, they will likely experience burns and unconsciousness in addition to heart problems. The heart will clamp which can cause internal burns, cardiac arrest, and death.
With that being said, it will generally cause a current of about 1,000 mA to cause death in a person. But how much current can an electric eel produce? Is it really enough to kill a human?
The Bottom Line: Can An Electric Eel Kill A Human?
In general, an electric eel will produce about 830 mA, but they may produce up to 1,000 mA in extreme cases. In theory, a current of 830 mA is not going to kill us, although it will cause muscle contractions and severe pain. In theory then, it would only be in extreme cases that an electric eel could kill a human. I.e. Only when the eel is producing its full amount of electricity.
Very few humans have died from the touch of an electric eel, but it has happened, and the fish does not always need to use its full electrical strength as you would assume.
Electric eels are freshwater fish, so if you’re shocked by them, you’re already going to be in or near the water. An electric eel will always shock with the strength to cause muscle contractions in humans. When someone experiences this shock while in water, they are significantly more likely to drown, even when standing in shallow water.
So, although the shock itself might not be strong enough to kill you, it can still lead to your death.