How Do Eels Make Electricity?
Electric eels have fascinated scientists and
the public for hundreds of years. Even Charles Darwin was puzzled by them. What is the shocking
secret behind an electric eel’s weapon? Hey guys Julia here for DNews Electric eels are some of the most shocking….
okay sorry had to do that once… organisms on this planet. They can harness the power
of electricity to hunt. But electric eels aren’t eels at all, they’re actually a
type of knife fish found in the Amazon River Basin in South America. They’re just one
type of dozens of fish that use electrical fields as sort of extrasensory perception.
But they’re the only ones with a charge strong enough to kill. Basically electric eels and other fish have
modified muscle cells that stack on top of each other. They work kind of like batteries.
Okay when I say kind of, I mean Alessandro Volta actually modeled batteries after electric
eels! Typically an eel can have as many as 6,000 of these cells called electrocytes.
These stacks of cells are negatively charged inside and their outsides are positively charged,
each cells has the potential of .08 volts. Not a lot, and considering the charges alternate,
no current flows. But as soon as the eel is triggered by spotting
a potential prey, these cells open up and an influx of sodium ions changes the polarity,
so now the stacks have a positive and negative end which creates an electric current. With
all the cells stacked together, in some species of fish, the charge can reach as many as 600
volts of electricity. While that might sound like a lot, it’s not enough to kill a man,
because the shocks are delivered very quickly in a matter of milliseconds. but it’s certainly
enough electricity to shock a small fish. But the coolest thing about electric eels
special shocking power, it’s not just for killing prey. Their shocks have a stealth
mode, they have a low voltage version that helps them hunt. These electric shocks act
an awful lot like sonar bats use. They can send them out as feelers, sensing if any fish
are lurking near by. But even their big shocks have a dual function.
One study published in the journal Nature Communications found it’s for hunting too.
The lead author of the study told National Geographic that “The eel can use its electric
attack simultaneously as a weapon and a sensory system, it’s sort of a science-fiction-like
ability.” Once they hone in on a prey they have a “remote
control” mode. They send out two closely spaced high-voltage discharges, called doublets
which makes the prey’s body contract involuntarily. This movement sends ripples through the water.
It lets the eel know it’s an alive thing and possibly prey. It can even make the fish
“freeze”. It shocks their neurological system so the fish can’t move. While ideal
for catching smaller prey, sometimes the shock isn’t enough for catching larger fish. So
an eel has to amp up their power. A recent study published in the journal Current
Biology found that eels boost their electric zap by curling into a circle. This brings
the positively charged end of their body, their head, with the negatively charged tail
area. By bringing the two points closer together, the fish can double their shock. While their shock isn’t enough to kill a
person, it’s still pretty painful. Those who’ve experienced it say it’s a lot like
running into an electric fence. So I wouldn’t exactly try fishing for one anytime soon.
As close as I’d like to get is Twitter. Miguel Wattson is an electric eel at the Tennessee
Aquarium sends a tweet whenever he sends out zap! check him out @EelectricMiguel But there are a ton of other animals I wouldn’t
touch with a ten foot pole. Electric eels and sharks often get a bad reputation for
being dangerous and deadly, but there are some freshwater animals you should be way
more terrified of. Julian and Natalia Reagan have the scoop on four Freshwater Animals
More Terrifying Than Sharks in this episode right here. Like the shockingly great shirt I have on?
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