Archerfish hunt by "spitting" at insects, arachnids, and even small lizard. The stream of water knocks the prey into the water, allowing them the fish to gobble them up.
New research suggests these fish are better shots than they have been given credit for. Archerfish use water as a toll, making them one of the only-known animals that adaptively change the hydrodynamic properties of a free jet of water, Cell Press reported.
"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," said Stefan Schuster of the University of Bayreuth in Germany. "It pays to be able to powerfully hit prey over a wide range of distances."
The team first made the discovery by training fish to hit targets between the heights of 20 and 60 centimeters, they monitored different aspects of the fishes' jet production and propagation.
They found the fish perform adjustments to ensure a perfect drop of water forms before impact. They achieve this by "modulating the dynamics of changes in the cross-section of their mouth opening." The fish demonstrated a "uniquely human" ability to throw a powerful shot.
"One of the last strongholds of human uniqueness is our ability to powerfully throw stones or spears at distant targets," Schuster said. "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."
The fish's unusual ability could help researchers gain insight into new innovations for human-built nozzles.
"The biggest problem is how to modify the abrasive properties of a jet," Schuster said. "Usually this is done by modulating the release pressure or by varying the abrasives added to the jet. We are not aware of someone actually using a dynamically adjustable valve."
The findings were published Sept. 4 in Current Biology.
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