PHYSICAL SCIENCE AND LIFE SCIENCE
Electric Eels
An electric eel is a slow-moving fish with no teeth and poor eyesight. It lives in the murky waters of muddy rivers in South America.
Instead of the senses that most animals use—vision, hearing, smell,
and touch—an electric eel uses electricity to find its next meal.
Since the fish that it eats often can swim much faster than the eel,
it also uses electricity to catch its prey.
Electric Sense
An electric eel actually has three pairs of electric organs in its body.
Two of them build electric charge for stunning prey and for selfdefense. The third electric organ builds a smaller charge that helps
in finding prey. The charge produces an electric field around the
eel. Special sense organs on its body detect small changes in the
electric field caused by nearby fish and other animals.
Shocking Organs
The electric eel builds an electric charge with a series
of thousands of cells called electrocytes. Every cell in
the series has a positive end and a negative end. Each
electrocyte builds only a small charge. However, when
all of the cells combine their charge, they can produce
about five times as much electricity as a standard electrical outlet in a house. The charge is strong enough to
paralyze or kill a human. Typically, though, the charge
is used to stun or kill small fish, which the eel then
swallows whole. Electric charge can also be used to
scare away predators.
EXPLORE
An electric eel (Electrophorus electricus) can deliver a jolt five times
as powerful as an electrical outlet.
1. INFER Electric eels live for 10 to 20 years,
developing a stronger shock as they grow
older. What could account for this increase in
electric charge?
2. CHALLENGE Sharks and other animals use
electricity also. Use the library or Internet to
find out how.
Chapter 10: Electricity 349