Fast Discharge Batteries: Electric Eels

by Emil Morhardt

We write a lot here about electric batteries of various sorts, but one of the oldest ones is the 600 Volt biological battery of the electric eel Electrophorus electricus. These animals search about for hidden prey by emitting a couple of high voltage pulses from time to time to see if anything jumps. If it does, they sidle on over and cut loose a volley of high frequency (~400 Hz) pulses that the muscles of the prey apparently interpret as coming from their own nervous system. The result is many muscles contracting simultaneously, paralyzing the prey into a state of whole-body muscle contraction known as tetanus (similar to the eponymous disease) and the eel sucks them in. This all happens pretty fast, on the order of milliseconds. If the eel fails to suck them in they often just swim away. Continue reading