Tuesday September 19, 2017

This man let an electric eel shock him repeatedly in the arm — all in the name of science

The eel's attack sent 40 to 50 milliamperes of electricity coursing through this scientist's arm.

The eel's attack sent 40 to 50 milliamperes of electricity coursing through this scientist's arm. (Current Biology)

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Kenneth Catania insists he was never in any real danger when he put his arm into a tank with an electric eel and let it shock him repeatedly for science.

"Though maybe a bit dramatic, it was not a big price to get some really clear data," Catania, a professor of biological sciences at Vanderbilt University in Nashville, Tenn., told As It Happens guest host Helen Mann.

"The eel was probably more scared than I was."

Catania has been studying the underwater creatures for four years, and he'd become fascinated with the way they sometimes leap from the water to zap people or animals, likely as a way to ward off land predators.

With less water to dissipate the electricity, a leaping attack packs more of a punch than an underwater shock.

"Basically that creates a very interesting electrical circuit and I was interested in analyzing that and it essentially became a puzzle, and the last part of the puzzle was to learn about the conduction of the human body," he said.

"I have a human body and a human arm, and I always tell my students to collect data whenever possible — so I like to say I put my arm where my mouth was."

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(Current Biology)

At 15 inches (38 cm), the eel was relatively small, he said. And while people sometimes drown after being shocked by an eel, the jolt itself is rarely fatal. 

What's more, he added, he could not think of any better way to measure the electrical current that flows through a victim's body when an eel delivers a leaping shock. 

"There would have been no good way to really imitate the interface between an eel and an arm, my hand in the water and the current flowing through it from the whole set-up," he said.

He measured between 40 to 50 milliamperes of electricity coursing through his arm from the eel's attack.

That's four to five times what it takes to make a person jerk away from a painful shock and, therefore, a pretty effective way to scare off predators.

So how does it feel?

"If you've ever worked on a farm and backed into an electric fence, it's a pretty similar kind of feeling," Catania said.

"It is surprisingly powerful. It is amazing thing that a small animal like that, it generated 200 volts of electricity. It's just, I think, an incredible creature all around."

The results have been published in Current Biology.