Archerfish snipe prey as accurately as humans throw baseballs.
Fish live almost exclusively in water, but sometimes the things they want to eat do not. That would pose a significant problem for most fish, but not the archerfish: Using water “bullets,” it’s able to snipe prey hiding on leaves and branches above the water, bringing them down to the surface. A study in the Cell Press journal Current Biology now reveals that archerfish are even more adaptable and accurate than previously thought, making them one of the few known animals to use water itself as a bonafide tool.
“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,” says Stefan Schuster of the University of Bayreuth in Germany. “It pays to be able to powerfully hit prey over a wide range of distances.”
In their research, they found that the archerfish’s mastery of its shooting skill is incredibly complex. After training the fish to hit targets at heights ranging from 20 to 60 centimeters from set locations, they observed some of the dynamics at work. For instance, the fish don’t blindly fire out the same jet of water and hope for the best. The time it takes for water to coalesce into a solid “bullet” at the end of the jet changes based on the target, meaning the fish use their mouths to control the water’s speed and volume.
The researchers liken it to the distinctly human skill of hard, accurate throwing, like pitching a baseball.
“One of the last strongholds of human uniqueness is our ability to powerfully throw stones or spears at distant targets,” Schuster says. “This is really an impressive capability and requires—among many fascinating aspects—precise time control of movement. It is believed that this ability has forced our brains to become bigger, housing many more neurons to afford the precision. With the many neurons around, they could be used for other tasks apart from applying them for powerful throws. It is remarkable that the same line of reasoning could also be applied to archerfish.”
They say the archerfish’s mechanism could have human applications, such as dynamically adjustable fluid jet valves, which as of yet not been commercially produced.
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