We've all heard the expression "as easy as shooting fish in a barrel." Well, if the barrel happens to be full of archerfish, they may be shooting back--and with a high degree of accuracy.
A new study shows that the sniper-like fish, which shoot their prey with jets of water squirted from their mouths, are capable of changing the force of their jets as they shoot for maximum efficiency.
It's the first time this ability has been observed in any animal, the scientists behind the study said in a written statement.
For the study, which was published in the Sept. 4 issue of the journal Current Biology, scientists trained archerfish to shoot at targets at various distances and then observed the action using slow-motion video.
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What exactly did the scientists find? The fish are uncannily accurate at hitting targets as far away as six-and-a-half feet--and they're able to give their jets extra oomph just at the moment of impact.
With water jets produced by human technology, the standard approach for increasing distance and force is to boost the pressure, Dr. Stefan Schuster, a biology professor at the University of Bayreuth Germany and the study's lead author, told the BBC. But, he said, archerfish "add nothing--they only shoot water, and they keep absolutely still during release of the jet, [which they shape] with the mouth opening diameter," adding that it's "not a simple maneuver."
Schuster said he believes the archerfish's unique shooting ability evolved in response to food scarcity.
"The predominant impression from our field work in Thailand over several years is that there is very little to actually shoot at, so it's important for the fish to be efficient," he said in the statement. "It pays to be able to powerfully hit prey over a wide range of distances."
WATCH the archerfish in action, above.