Adaption

The bodies of Electric Eels hold electric organs. These organs contain about 6,000 specialized cells called, electrocytes. Electrocytes store power, and, when threatened or attacking, these cells emit a powerful burst of 600 volts. This adaptation increases the chances of survival by protecting from predators and killing prey.

Sources:

Image and information

http://animals.nationalgeographic.com/animals/fish/electric-eel/