“Ouch! That hurt!”— that’s what one would say when struck by 800 V of electricity for a few seconds. But when this jolt comes from the electric eel, the disgust soon turns into wonder because this South American native is the world’s strongest bioelectricity generator! Electrophorus electricus is not really an eel but belongs to the knifefish family, and is closely related to carp and catfish. At about six feet long and weighing around 20 kg, most of the electric eel’s body has been specifically designed to produce the strongest electric shocks that it uses to stun its prey and navigate. How often does the eel produce these shocks? To know that, follow @EelectricMiguel on Twitter; that’s Tennessee Aquarium’s Miguel Wattson—the world’s only electric eel that sends out a tweet whenever it generates an electric pulse!
The fish’s body contains three electricity-generating organs in the abdomen that contain disc-shaped cells called electrocytes. These cells are positively charged on the outside and negatively charged on the inside. When an eel spots a prey or wants to defend itself, the brain sends a signal to these organs so that one side of each stack of electrocytes becomes positive and the other side becomes negative, resulting in an electricity flow. The eel uses a high-voltage shock to immobilise prey, and a low-voltage shock to give a twitch to a lurking prey to better locate it. Don’t worry about these fish electrocuting themselves—a layer of proteins in their organs insulates them!
These fish have intrigued scientists since the 1700s. John Walsh, a British scientist and a former governor of Bengal, first demonstrated how these fish generate sparks. Inspired by these ‘living batteries’ scientists today are developing medical implants, like pacemakers, that generate their own electricity.