Joe Clarke, age 11, of Danville, I11., for his question:

WHY DOES AN ELECTRIC EEL HAVE ELECTRICAL POWER?

The electric eel depends on its ability to produce an electric shock as its way to catch food and also to protect itself from enemies. It can also detect objects at a distance under water by electricity. In addition, weak shocks also serve as a telegraph to other eels.

The electric eel is actually not an eel at all. It is related to carp and catfish and is called an eel because its long, snaky body makes it look like one. Inside, however, it is much different from an eel. Most of its organs lie in the front fifth of its body while the other four fifths mainly hold the organs that make the electric current.

The tissues of the organs in the back of the electric eel consist of many layers built one behind another like the plates in a battery. The current they produce flows from the head to the tail.

When excited, the electric eel produces strong shocks in sets of three to five. Each impulse lasts for only a fraction of a second but the eel can keep them up for a long time, perhaps hours. They usually reach about 200 to 300 volts, which is enough to stun a man or a horse. Usually electric eels have been known to discharge 500 to 800 volts.

The electric eel lives in shallow waters of the Amazon and Orinoco rivers in South America.