Scientists do all sorts of weird shit in the name of knowledge, but this might be near the top of the list. To explore how electric eels transfer electricity to another animal when they shock it, Vanderbilt University biologist Ken Catania, Ph.D., stuck his arm into the water with an electric eel and let it shock him.

In this paper, which came out in the journal Current Biology on Thursday, Catania attempted to confirm that electric eels can jump to attack their prey. In his video, he accomplishes his goal. Eels leap out of the water, he explains, to attack potential predators because it makes it easier for smaller eels to deliver an exceptionally painful shock.

“Apparently a strong offense is the eel’s best defense,” writes Catania in the paper. By connecting directly to a predator instead of just electrifying the water that they share, the eel’s attack is more efficient.

electric eel jumping
The electric eel leaping in Catania's previous experiment.

Catania, a professor of biology and neuroscience at Vanderbilt University, has published a number of studies on electric eels in the past few years, so this isn’t his first eel rodeo. But this is the first one that involves him intentionally allowing himself to be shocked. He did so to measure “the electromotive force and circuit resistances that develop during an eel’s leaping behavior.”

In a previous study, Catania had tested this with a fake predator, but this time he used his own arm, which you can see in this insane slow-motion video.

The shock, which comes in pulses, isn’t very strong, but Catania says it hurts enough to serve as a strong deterrent. As the diagram below shows, Catania used a device that kept his hand insulated from the eel’s electric shock in the tank but allowed the current to return to the eel, forming a complete circuit. Wires in the water detected the current so Catania could analyze it.

electric eel

The study also includes this gem of a humblebrag: “Although 40–50 mA may not seem like much electrical current, it is far above the levels usually used to study pain and reflexive withdrawal reflexes.”

So yeah, the jolt from an electric eel leaping out of the water might not harm you, but it’s definitely — wait for it — shocking.


This velvet worm ain’t messing around! Check out this video about one of the fiercest predators on the planet.