Fish generator to advertise themselves

New research shows that male fish can increase their body's electric field to seduce females and threaten their opponents. Some fish have the ability to generate power. Few births are strong enough to stun predators and defend - most use their power to navigate in water or communicate in the dark.

The weak fish species are gymnotiform fish ( Brachyhypopomus pinnicaudatus ), a toothless fish native to the Amazon river. At night, the males emit their own long and loud humming hummingbirds.

Such spectacular performances are often a great challenge with the goal of attracting heterosexuals. Difficulties are a way to reveal their abilities and prove their worth. Previous studies have shown that producing an electric performance is not too complicated for them, so it doesn't seem attractive.

To test the energy that electric fish use for signaling, behavioral ecologist Vielka Salazar of Florida International University in Miami and colleagues measured the amount of oxygen they consumed during electricity generation.

Salazar found that males spend about 11% to 22% of their energy on night performances. The fish almost never use this ability, only 3% of body energy.

Speaking to LiveScience, Salazar said: 'If the performances are too expensive, we can assume that the quality of a male is determined by the signals it emits.' When Salazar checked the fitness of the males, she found that the best big ones would broadcast the largest electrical signals. In this way, they are advertising themselves.

Researchers are learning more to come to the conclusion whether these electrical signals are used to attract females, alert enemies or both functions. Salazar and adviser Philip Stoddard published their findings in the February 29 online edition of the Journal of Experimental Biology.

Gymnotiform fish - Brachyhypopomus pinnicaudatus (Photo: LiveScience)