Electric eels are considered one of the most remarkable predators in the animal kingdom. They can generate a strong electric charge to shock their prey to death and to keep other predators at bay. Now, a researcher has measured how strong that shock can be. For this purpose, he allowed an electric eel to jolt his arm and recorded the entire experiment. And the results were not too surprising.
“We’ve known these animals give off a huge amount of electricity, and everybody thought that was really amazing,” said biologist Kenneth Catania of Vanderbilt University, who experienced the shock. “But they aren’t just simple animals that go around shocking stuff. They’ve evolved to produce stronger and stronger electrical discharges, and in concert, they’ve evolved these behaviors to more efficiently use them.”
Catania has spent years to study the way these isolated fish emit electrical fields and use them to stun their prey. Electric eels leap from the water to deliver painful, Taser-like jolt to their prey or potential predators. For the latest study, he wanted to measure the actual intensity of an eel’s zap and it was not possible without real human skin.
To understand the strength of the electrical circuit created when an eel contacts another animal, Catania designed an apparatus consisting of a small container and a water-filled tank with an eel inside it. He used a relatively small, 15 inch electric eel for the experiment.
The container allowed his hand to go into the eel’s tank and to accurately measure the flow of current through a human arm as the electric eel jumps to attack.
Catania found that electrical current delivered by the eel peaked at 40 to50 milliamps. That’s more than enough to cause a person or animal a shocking pain, but not enough to actually hurt them. Catania immediately withdrew his hand as the eel jumped to his arm. His reaction suggested that its intensity was similar to that of touching a hot stove.
“It’s impressive that a little eel could deliver that much electricity,” said Catania. He had accidentally received a couple of shocks from eels before. So he already had an idea about their strength.
“We don’t know the main driver of the behavior, but they need to deter predators, and I can tell you it’s really good at that. I can’t imagine an animal that had received this (jolt) sticking around.”
With these baseline measurements, Catania believes it is now possible to estimate the power of a shock delivered by eels of various size under different circumstances.