New research found an electric eel's shock is comparable to a Taser and allows the snake-like aquatic creature to seek out and incapacitate its prey.
People have known about the extraordinary abilities of electric eels for centuries, but until now nobody had figured out how their high-voltage system worked, Vanderbilt University reported.
To make their findings the researchers placed several eels in a tank equipped with devices that can sense electric signals and a high-speed video system. The research team observed the eels were surprisingly quick, allowing them to swallow prey in about a tenth of a second.
The researchers observed three different types of electrical discharges given off by the eels: "low-voltage pulses for sensing their environment; short sequences of two or three high-voltage millisecond pulses (called doublets and triplets) given off while hunting; and volleys of high-voltage, high-frequency pulses when capturing prey or defending themselves from attack," the researchers reported.
The eels would hit their prey with high-voltage pulses about 10 to 15 milliseconds before striking. This completely immobilized the prey before the eel even touched it.
"It's amazing. The eel can totally inactivate its prey in just three milliseconds. The fish are completely paralyzed," said Kenneth Catania, Vanderbilt University Stevenson Professor of Biological Sciences.
The researchers then looked into how the eels accomplished the extraordinary feat.
"I have some friends in law enforcement, so I was familiar with how a Taser works," Catania said. "And I was struck by the similarity between the eel's volley and a Taser discharge. A Taser delivers 19 high-voltage pulses per second while the electric eel produces 400 pulses per second."
Tasers immobilize their victims by overwhelming the nerves that control the muscles, causing them to contract; the team found the eel's electric pulses have a similar effect on their targets.
"If you take a step back and think about it, what the eel can do is extremely remarkable," Catania said. "It can use its electrical system to take remote control of its prey's body. If a fish is hiding nearby, the eel can force it to twitch, giving away its location, and if the eel is ready to capture a fish, it can paralyze its muscles so it can't escape."
The findings were published Dec. 5 in the journal Nature.
