Researchers unravel the complex system that gives eels the ability to remotely control the nervous systems of their prey while they hunt and kill them. Ben Gruber reports.
STORY: That was the sound of 400 volts of electricity turning a fish into dinner for a hungry eel. Vanderbilt University biologist Ken Catania says eels may just be one of the most fascinating killers on the planet. Until recently it was thought that eels simply shock their prey to death before eating them. Catania had a hunch the process was more complex. He used a high speed camera to slow down time and stretch out the milliseconds it takes an eel to hunt and kill. (SOUNDBITE) (English) KEN CATANIA, PROFESSOR OF BIOLOGICAL SCIENCES, VANDERBILT UNIVERSITY, SAYING: "As soon as I filmed them with a high speed camera I saw some amazing things and I was kind of hooked on to a research path to try and understand what was going on." And what Catania saw was a complex series of electrifying events that unravel faster than a blink of an eye and that almost always ends with an eel catching and eating its desired prey. It starts with an eels' unique anatomy. (SOUNDBITE) (English) KEN CATANIA, PROFESSOR OF BIOLOGICAL SCIENCES, VANDERBILT UNIVERSITY, SAYING: "The front one fifth, maybe, of the animal is all of the normal internal organs and the back end is mostly muscles that have been converted into energy generating batteries that are lined up in a series like a big flashlight." And that flashlight is powerful, with large eels giving off enough voltage to kill a horse. Catania found that eels use a pair of low intensity pulses to make their victims involuntarily twitch, revealing the target's exact location. Then the predator unleashes its high powered electric salvo which leaves its prey literally frozen in a state of shock. To accomplish this Catania found that eels basically take over their victims' nervous systems. (SOUNDBITE) (English) KEN CATANIA, PROFESSOR OF BIOLOGICAL SCIENCES, VANDERBILT UNIVERSITY, SAYING: "So it really is a remote control in a sense of the eels' neurons activating through the electric generating organs the neurons in the prey. And so they are remotely activating their preys' muscles and essentially taking over their peripheral nervous system." Catania says there is still a lot to learn from eel, like how their bodies are shielded from the intense electricity they produce. But for now, he says, figuring out the shocking truth of how eels kill has been an electrifying experience.