ILLUSTRATIONS Alexandre Jubran
QUESTION Michel Marcelo Monteiro, Sao Paulo, SP
It does not need to protect itself, as it is adapted to live with the current it produces. The eel has special muscle structures with cells called electrocytes, which convert energy not expended in locomotion into electrical impulses. This electricity is accumulated and creates a field around the animal, which guides its movement, protects it from predators and helps it capture its prey.
1. An adult eel can have up to 160,000 electrocytes (a type of cell that accumulates and emits electricity), especially in the lower part of the body. They are arranged like batteries in a remote control: the negative pole of one is in contact with the positive of the other.
two. This arrangement allows the circulation of an electric current, that is, the flow of particles carrying an electric charge. Thus, the animal becomes a “live battery”: its negative pole is located near the tail and the positive pole is located in front, just before the head.
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3. One of the consequences of this current is the creation of a electric field around the eel. If she feels changes in the frequency of this field, it is because it has been invaded. Instinctively, the animal emits discharges of up to 600 volts (equivalent to almost five household outlets), enough to paralyze or kill the invader.
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SOURCES Claudia Marques Rosa, biologist, and Claudio Furukawa, from USP’s Institute of Physics