Electric Eel

The electric eel is a large, elongated fish native to the freshwater rivers and swamps of the Amazon and Orinoco basins of South America, and despite its common name it is not a true eel at all but a member of the knifefish order, more closely related to catfish and carp. It is famous for its extraordinary ability to generate powerful electric shocks, exceeding 600 volts in the strongest recorded discharges, using three specialized electric organs that make up most of the length of its body, which it uses both to stun or kill prey such as fish and to defend itself against predators. Electric eels breathe partly by gulping air at the surface, an adaptation that lets them survive in oxygen-poor water, and they are mostly nocturnal, poor-sighted hunters that rely on weak electrical pulses to sense their surroundings in murky water. Though a shock from a large electric eel is rarely fatal to a healthy adult human, repeated or prolonged exposure can be dangerous, and the species has long fascinated scientists as a natural source of insight into bioelectricity.