Electric eels, which are known for unleashing a potent electrical jolt to wallop their hapless prey, don't just use this zap to stun other fish.
A new study, released this week, shows that eels use their jolt to exert a form of remote control over their victims, which causes fish that may be hiding to twitch, thus exposing their location.
"Apparently, eels invented the Taser long before humans," said biologist Kenneth Catania of Vanderbilt University in Nashville, Tennessee, who conducted the research published on Thursday in the journal Science.
The study indicates how precisely an eel's zap affects its victim. During laboratory analysis, Catania showed how the electrical discharges remotely activate the prey's neurons (nerve cells) that control the muscles.
Eels periodically give off two high-voltage pulses while hunting, separated by a 2 millisecond pause, which causes a massive involuntary twitch in nearby hidden prey, according to the study. The eels can then detect motion caused by the twitch, revealing the location of other fish.
"I have spent much of my career examining extreme animal adaptations and abilities. I have seen a lot of interesting stuff, but the eel's abilities are astounding, perhaps the most amazing thing I have ever observed," Catania said.
"After all, they can generate hundreds of volts - that by itself is incredible. But to use that ability to essentially reach into another animal's nervous system and activate their muscles is a pretty good trick," Catania added.
Electric eels can reach lengths of 6 to 8 feet, prowling the Amazon and Orinoco river basins. They have electric organs with specialized cells called electrocytes that serve as biological batteries and generate an electrical charge of up to 600 volts to attack prey or defend against predators.
"Although they are not known to kill people, they are capable of incapacitating humans, horses and obviously fish during their electric discharge," Catania said.