If your knowledge of electric eels is limited to what you've seen in cartoons or movies, we wouldn't be shocked. These odd animals are a strange feat of evolution. You may think Hollywood has overplayed the electric eel's abilities, but it really is a creature to avoid. Here are eight facts to set the record straight about electric eels — and probably scare you a bit!
Electric eels aren't eels
Surprise! Despite its eel-like appearance and the misleading common name, this South American fish is a species of knifefish and is closely related to catfish. It’s scientific name is much more fitting: Electrophorus electricus. The electric eel is such an oddball animal that it has been reclassified several times. Scientists finally landed on putting it in its own genus, Electrophorus.
Electric eels deliver quite a shock
Editor's note: Sometimes we get it wrong, and this is one of those instances. If you read an early version of this story, you'll know that we wrote an electric eel delivers a shock five times more powerful than a standard U.S. wall socket. Sounds impressive — but it's not true. Rhett Allain over on Science Blogs does a great job of explaining why we (and many others, it turns out) got tripped up: It's the confusion between electric potential (measured in volts), power (measured in watts) and current (measured in amps).
It's true that you really shouldn't go around sticking your finger in a wall socket, nor should you try to hug an electric eel. But the real numbers aren't quite as harsh as we originally spelled out. A wall socket has a maximum power of about 1,200 watts; during an attack, an eel has is capable of about 500 watts. As Allain explains (much better than we could:
An electric eel has multiple cells along its body that create a change in potential of over 500 volts. The typical current produced in an electric eel attack is around 1 amp.
500 volts would be the same potential as about 330 D-cell batteries connected together. A typical two-battery flashlight might use a current of about 1 amp. However, since the eel has a much larger potential difference, the effects can be severe.
It isn’t necessarily a shock that can kill a person, and attacks on people are rare, but an encounter could potentially lead to death.
“Although there are few documented instances of people dying from an electric eel's shock, it could happen. A single jolt could incapacitate a person long enough to cause him or her to drown, even in shallow water. Multiple shocks could cause a person to stop breathing or go into heart failure,” according to How Stuff Works.
Electric eels use this ability not just to hunt but also to deter attackers. The fish have delivered shocks so powerful they've killed horses, and there's even video of one shocking the daylights out of a caiman (warning for those who are sensitive):
Electric eels lay eggs in nests of saliva
In what is one of the most odd and gross forms of parenthood, male electric eels will create a nest of spit into which females will lay thousands of eggs. An average of 1,200 baby eels will hatch from the well-guarded nest. Both the male and female stick around to protect their offspring until the juveniles are around 4 to 6 inches long.
Electric eels are mouth-breathers
Another adaptation for the muddy and poorly oxygenated waters in which they live is that electric eels don’t rely on their gills to breathe. They get around 80 percent of their oxygen by gulping air at the surface of the water. Indeed, if an electric eel is denied access to air at the surface, it will die.
Electric eels use their electric charge like a radar system
Since electric eels live in muddy water, their eyesight isn’t great. Why bother evolving excellent vision if you can’t use it? But they can use their electricity to “see.” This fish species will utilize small pulses to find prey. After delivering a shock to their prey, the eels will follow the electric field like a radar, zeroing in on their incapacitated prey without using sight or touch.
According to a 2015 study by scientist Kenneth Catania that looked into this ability for the first time, “electric eels use high-voltage simultaneously as a weapon and for precise and rapid electrolocation of fast-moving prey and conductors. Their speed, accuracy and high-frequency pulse rate are reminiscent of bats using a ‘terminal feeding buzz’ to track insects.”
This video explains more about how electric eels hunt with their electrifying system:
Electric eels curl up to concentrate their shocking powers
Catania also found eels use a clever strategy to handle fast or awkward prey. Once they bite down on prey, they curl around, holding the prey near their tails. This strategy increases the shock the prey receives.
Curling boosts an eel’s electric field to trigger hard and fast contractions in prey, leading to muscle fatigue. Prey are then too tired to struggle and escape – the animals are completely paralyzed. After biting its prey, an eel moves around the victim’s body so that it become sandwiched between the predator’s head and tail – the positive and negative poles of an electric field. This maneuvre will amplify the voltage experienced by prey by bringing the two poles closer together, which enables the predator to perform a ‘dipole attack’. Through measurements using electrodes in fake prey, Kenneth Catania has found that curling at least doubles the strength of an eels’ shocks.
Electric eels will leap from the water to attack
As if all this information about how powerful and clever electric eels are isn't unnerving enough, a new study shows they will actually leap from the water to attack predators. That’s right, they don’t just stay put under the surface.
While handling electric eels using a net on a metal rod, our favorite electric eel researcher Catania noticed the eels would attack the rod as it approached, lunging up from the water to hit it with electric shocks. In a series of experiments, Catania realized this is not just a mindless lunge but a strategy.
“Catania noticed that the electric eels were coordinating their leaps with volleys of high-voltage pulses... [B]y leaping, the eels progressively electrify greater portions of the partially submerged target.” reports National Geographic.
The eels even bend their necks to keep in contact with the target, ensuring whatever predator they’re defending against feels their full wrath. Watch the behavior in action in this video from the study:
The theory is that this strategy is beneficial when the eels are stuck in small ponds during the dry season and have a particularly high need to defend themselves against land-based or semi-aquatic predators such as, you guessed it, caiman.
Electric eels can reach more than 8 feet in length
Now that you know how cunning and effective their hunting strategy is, we thought we'd throw in this one last fact, just to fully terrify you. Eight. Feet. Long. You probably don't want to go swimming in electric eel territory any time soon.