Shocks in the water cause the writhing of hidden animals. In this way they can easily locate their victims.
The electric eel, also known as electric fish, for here or just eel, can unleash a powerful electric discharge to attack its defenseless prey. But this shock is not only used to stun other fish.
A new study shows that eels use electricity as a remote control over their victims, causing hidden fish to wriggle, exposing their location, or inducing involuntary muscle contractions to incapacitate their prey.
They use shock to paralyze their victims from afar.
"Apparently they invented taser long before humans," says biologist Kenneth Catania of Vanderbilt University in Tennessee, who conducted the research published December 4, 2014 in the journal Science.
The study reveals precisely what an eel's shock does to its victim. In laboratory experiments, Catania showed how lightning strikes remotely hit the prey neurons that control the muscles.
While hunting, eels periodically give two high voltage discharges with a 2 millisecond pause between them, causing a collective involuntary contraction in animals that may be hiding nearby. Eels, very sensitive to movement in water, can detect the movement caused by contraction by discovering the location of the fish.
The eel then gives a longer and more intense shock to immobilize the prey, causing involuntary contraction of the muscles, like a taser pistol, allowing its capture.
"I've spent most of my career examining extreme adaptations and animal skills. I've seen a lot of interesting things, but the eel's abilities are amazing, perhaps the most amazing thing I've ever seen," says Catania.
Electric eels, with snake bodies and flat heads, can range from 1.8 to 2.5 meters and live in the Amazon and Orinoco river basins.