Electric Singing and Arguing

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The brown ghost knifefish, popular in many aquariums, generates a weak electric signal that it uses for navigation and communication. The electric field they generate is too weak to stun prey. However, the electric organs that run along the sides of their bodies can pick up any changes in the field when the field encounters something with a conductivity that is different than water.

The communication aspects of the field are even more amazing. Male knifefish have been recorded singing to females by modulating their electric field. Researchers report that the males will sing like this for hours at night. However, when two knifefish who are hostile to one another encounter each other, they will raise the frequency of their electric field to jam their rival’s signal. Researchers confirmed their conclusion that the knifefish were attempting to jam an enemy’s signal by using a dummy knife fish. They rigged the dummy to generate signals that mimicked a knifefish. Then they placed two male knifefish in the tank with it. The two males were rivals to the dummy and both male knifefish quickly raised their frequencies to jam the rival’s signal.

Some people believe that mindless evolution gave the knifefish the ability to generate and control electric fields for communication, as well as the ability to receive those signals. That credit clearly belongs to God!