Sharks Have a Sixth Sense for Killing, Literally
They're better at sensing electric fields than even our best tools
By Michael Harthorne,  Newser Staff
Posted Aug 9, 2015 8:03 AM CDT
In this undated file publicity image provided by Discovery Channel, a great white shark swims near Guadalupe Island off the coast of Mexico.   (AP Photo/Discovery Channel, Andrew Brandy Casagrande, File)
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(Newser) – It turns out there's something sharks are even better at than spicing up your average made-for-TV movie about tornadoes: sensing electricity. Back in 1971, a Dutch scientist discovered sharks use tiny pores on their heads to sense the electric fields produced by other aquatic animals—and hunt those creatures, Atlas Obscura reports. These electric fields are produced by the differences in ion concentrations between animals and the water and allow sharks to close in for the kill in murky or dark water from about a foot and a half away. LiveScience in 2006 reported that the sense was "so developed" that sharks could even track down fish who had buried themselves in the sand.

What's even more impressive is where sharks fall on the spectrum. According to Atlas Obscura, sharks are approximately 10,000 times more sensitive to electric fields than any other animal and are even more sensitive than the best machines made by humans. Here's how sensitive: "They can detect electric field gradients as small as a billionth of a volt across a distance of a centimeter." What does this sixth sense mean for fearful summer beach-goers? Atlas Obscura reports humans' insulating skin dampens any electric fields that would be sensed by sharks, but opening your mouth underwater could produce one by way of the mucous membranes there, leaving one biologist to advise, "Don't scream." Read the full Atlas Obscura article here.