Certain fish produce electricity to kill their prey or to defend themselves. The electric eel, a South American fish with a long, wormlike body, can grow to a length of 9 feet (2.75 meters) and weigh nearly 50 pounds (22.7 kilograms). The electric eel floats through slow-moving water, searching for fish to eat. It breathes air, which means it must come to the surface every few minutes. The electric eel has organs made up of electric plates that run the length of its tail, which makes up most of its body length. This eel, which has no teeth, uses electrie shocks to stun its prey, probably to protect its mouth from the struggling, spiny fish it is trying to eat. The eel shocks the fish with several brief electrical charges, temporarily paralyzing it so the eel can suck it into its stomach. The electrical charge can be anywhere from 300 to 600 volts, enough of a shock to jolt a human being.
Electric rays have two special kidney-shaped organs that generate and store electricity like a battery. A large Atlantic torpedo ray can produce a shock of about 220 volts, which it uses to stun its prey before eating it. In addition to stunning potential prey and discouraging possible predators, the electric organs of electric rays may be used to communicate with each other. Like the rays, the electric catfish of Africa produces an electric shock of up to 400 volts, which it uses for self-defense and prey capture. Mormyrids, which live in very muddy waters in West Africa, use electrical signals as a form of radar, allowing them to travel safely and to find food.