Tennessee – Electric eels are cunning hunters that are found in the waterways of South America’s Amazon and Orinoco regions. A recent study published on Wednesday in the Current Biology journal has described how these remarkable creatures use basic physics to double the voltage of their electric current discharged onto their prey.

A new study found that when dealing with a struggling prey, eels bend their bodies into a horseshoe-like shape to more than double the voltage they deliver to their victim. Credit: Kenneth Catania

Hunting strategies

The creature, which scientists call Electrophorus electricus, stands out due to its uncommon electrical weaponry and unique hunting strategies. Eels generate hundreds of volts of electricity through their body. When they conduct this shock onto their prey, as a result of high rates of discharge, the victim’s muscles contract resulting in immobilizing tetanus. Eels then take advantage of this precise period to seize their prey and swallow it completely as a whole.

How do they create the shock?

The eels’ body store electricity in cells known as electrolytes. These cells are then responsible for discharging a voltage delivered in 1 ms pulses, at rates that approach 500 Hz when they feel threatened or during hunting.


Now the current study has found that eels can increase their voltage by doubling up their body’s size. When faced with a large prey, electric eels begin their attack by curling up to bring their own tail to the opposite side of prey. Then they position the prey’s body between the positive and negative poles which alters the configurations of the electric field. This causes them to double their power and distribute volleys of high-voltage pulses off of their electric organ.

Kenneth Catania, a Professor of Biological Sciences of Vanderbilt University and author of the study, stated to the Washington Post, “I’m personally amazed at this animal. Historically, they’ve been considered very unsophisticated, primitive creatures that shock their prey. To see them manipulate their electric field and do these more intricate things is really amazing.”

Investigators also discovered several other functions of this electric field. The first one is as a tracking device. These electrical pulses send out a type of sonar signal that can guide eels where their prey stands without using any other senses.

“Electric fish, in general, have the ability to sort of probe their environment with electricity,” Catania added. The other is to push preys out of hiding by directly attacking their neurons.

To prove his theory, Catania replaced the prey with a piece of carbon rod which would be more conductive than water itself and wouldn’t interfere with the experiment. Then when he made the carbon move the electric eel would initially go after the movement in the water. After, the eel would send a high-voltage pulse to follow the conductor.

Source: Current Biology