Electric Eels Hunt By Tracking Electrical Currents In Their Prey

It's electrifying!

Electric Eel

Electric Eel

ravas51/Flickr CC by SA 2.0

So it turns out that The Princess Bride was actually pretty scientifically accurate. At least when it comes to the eels.

Remember those guys? The shrieking eels would get louder as they approached their target. Thankfully, the shrieking eels remain a species firmly rooted in fantasy, but their real-world counterparts, the electric eels have pretty similar hunting behavior. Only instead of shrieking, electric eels use intensifying electrical charges to track and stun their prey.

In a paper published today in Nature Communications researchers showed that electric eels not only use their famous electric charge to stun their prey, they also use the charge to track down their dinner.

From previous research (done by the same team), the scientists already knew that the eel's electrical impulse could make a fish involuntarily twitch, showing the eel where their prey was hiding. But this new study shows just how reliant electric eels are on that electric signal.

By hooking up a dead fish to an isolated electric current, the researchers were able to make that fish twitch, seemingly in response to the eel's electrical impulses. But when the eel approached, they switched off the current, and sent a charge through a carbon rod instead. Instead of going for the tasty fish, the eel immediately switched gears and grabbed the rod instead. Other experiments included passing a charge through varying points and seeing how the eel responded--the eel ended up attacking the charge. The researchers also found that when there was no electrical current present, the eel didn't strike.

Oh, and just like the shrieking eels, electric eels do get more intense as they get closer to their prey. It's simply that instead of the sound used by shrieking eels (or bats in the real world) it's the eel's electrical impulses that ramp up dramatically.

See the tests in action here: