electric eel

The electric eel is long and narrow like an eel, but it is actually not an eel at all. In fact, electric eels are probably more closely related to catfishes. A large adult electric eel can deliver a charge of up to 650 volts—to stun prey, keep away predators, and to help them navigate through muddy water.

Image credits: main image, courtesy of Alan Hill, Fishbase.