A jolt from an electric eel does more than stun its prey, scientists say.
A study, reported in the journal Science, has now shown that eels can use their electric organs to remotely control the fish they hunt.
A researcher from Vanderbilt University in Nashville, Tennessee, found that the electric discharges from eels made the muscles of their prey twitch.
This makes the fish easier to capture either by immobilising it or making it "jump" to show where it's hiding.
Kenneth Catania, who led the study, set up small aquatic arenas to test the eels' hunting abilities - putting an eel and an unfortunate fish into the same tank.
Electric eels "reach into the nervous system" of their prey. When they spotted their prey, the eels released pulses of electricity that appeared to immobilise the fish.
Further study revealed that the eels' electric pulses directly activated the nerves that controlled their prey's muscles.