itat at night (it's nocturnal), the electric fish orients itself by periodically emitting a weak electrical discharge:
This lower voltage can be used to "see" surrounding objects. Objects with a different conductivity will distort the electric field that the eel produces, thus making the eel aware of the object's presence.
After locating its prey with weak electrical pulses, E. electricus kicks it up a notch:
Once prey is found the electric eel will use a much larger electrical current to stun the fish.
Toothless, electric fish eat their prey by "open[ing] their mouths to create a suction," and swallowing the meal whole.
Able to produce a voltage as high as 650 volts and about 1 amp, the electric fish emits a strong, brief (2 milliseconds or less) shock when it is attacked by a predator. Although experts say the shock is rarely fatal by itself, it can kill some animals.
How Does it Produce Electricity?
E. electricus' nervous system controls its production of electricity:
Each electrogenic cell [electrocyte] carries a negative charge of a little less than 100 millivolts on its outside compared to its inside. When the command signal arrives [from a "command nucleus" in the nervous system], the nerve terminal releases a minute puff of acetylcholine, a neurotransmitter.
Through nerves on one side of the cell, causing ion channels to open on that side. Sodium ions are able to rapidly enter the cell via these channels . . . [which] alters the equilibrium of the cell. To re-establish [it], potassium ions leave the cell on the other side,. . . .
A transient path with low electrical resistance connecting the inside and outside of the cell. Thus, each cell behaves like a battery with the activated side carrying a negative charge and the opposite side a positive one. Because the cells are oriented inside the electric organ like a series of batteries piled into a flashlight, the current . . . set[s] off an avalanche of activation that runs its course in just two milliseconds. . . [and] creates a short-lived current flowing along the eel's body.
Can Its Energy Be Harnessed?
Scientists have long been impressed with the electrical generating ability of E. electricus, and recent research is leading to uses that may benefit people.
Since 2009, scientists at the Living Planet Aquarium in Sandy, Utah, have been harnessing the power of their resident electric tree to power the lights on the aquarium's Christmas tree.
Essentially, two stainless steel electrodes are attached to Sparky's (the electric fish) tank, and each time Sparky sends out a pulse, which is part of "his natural, normal activity," currents of electricity travel through the electrodes to sequencers that make the lights on the tree flash. Living Planet's marketing director loves the display because it "helps give a visual idea of what an animal really does on a daily basis."
Some medical implants and devices require batteries to power their complex functions. In recent years, scientists have been looking for ways to create "bio-batteries," that "would be just like any other cell in your body," except they also produce electricity.
A few researchers have been investigating whether E. electricus' electrocytes might make a goodblueprint, and are:
Designing an artificial cell that could replicate the electrocyte's energy production. . . . [They] found that an artificial cell could actually out perform a natural cell.
One hurdle to producing a viable bio-battery is finding a human-safe power source, although "bacteria cold be employed to recycle ATP – responsible for transferring energy within the cell – using glucose."
Researchers remain hopeful, particularly since the bio-battery has many advantages including: "if it breaks, there are no toxins released into your system."
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