

Vanderbilt University biologists studied how electric eels can zap their prey with 600 volts from even a few meters away. Turns out, the fish are like living TASERs. Professor Kenneth Catania and his colleagues published their work in the journal Science.







To conduct the new study, Kenneth Catania, a biologist at Vanderbilt University in Nashville, recorded electric eel (Electrophorus electricus) attacks on smaller fish, such as koi, in a large tank with a high-speed video camera, capturing 1000 frames per second. At the same time, he recorded the pulses emitted by the eel and the muscle contractions of the fish. When an eel senses the movements of a nearby fish, he showed, the eel releases a high-voltage volley of electric pulses that not only shock the fish as it's trying to swim by, but also cause a massive, involuntary contraction of the animal's muscles, freezing it in place. If Catania injected the fish with a drug that blocks communication between nerves and muscles, however, its muscles weren't frozen. That experiment showed that the eel's shock immobilizes its prey's muscles by stimulating the fish's motor neurons. It's the first time a fish's electricity has been shown to have such a specific biological effect in prey. "The eel is a swimming Taser," Catania says. "The mechanism is the same."