South American Knifefishes and Electric Eels: Gymnotiformes

Physical characteristics: Electric eels can reach a length of 8 feet (2.4 meters). They have no dorsal, tail, or pelvic fins and do not have scales. The bottom part of the head and throat is yellowish to orange, and the rest of the body is dull olive to almost black. These fishes produce electric discharges as strong as 700 volts.

Geographic range: Electric eels live in northern South America.

Electric eels are active at night. They stun prey or food animals with electric shocks. (Hans Reinhard/Bruce Coleman, Inc. Reproduced by permission.)

Habitat: Electric eels live in creeks and ponds and along the shores of lakes.

Diet: Electric eels eat mostly other fishes, but they also eat amphibians (am-FIB-ee-uns), such as frogs, which spend part of their lives in water and part on land.

Behavior and reproduction: Electric eels are active at night. They stun prey or food animals with electric shocks. These eels drown if they cannot get access to air, so they swim to the surface every ten minutes or so to gulp air. They hide during the day under shelter or in holes. Electric eels breed during the dry season in small ponds. The male builds a foam nest. The larvae first eat eggs of later spawnings, then change their diet to insect larvae. These eels start eating fish when they are about 4 inches (10 centimeters) long. The males guard the young until they can eat fish.

Electric eels and people: Electric eels have been used to study how electricity works in biology.

Conservation status: Electric eels are not threatened or endangered. ∎