Archerfish Shoot Water 'Bullets' with More Skill and Accuracy Than Expected

Archerfish have the amazing ability to hunt by shooting jets of water at unsuspecting insects, spiders and even small lizards on leaves or twigs above, causing them to fall into the water and allowing the fish to swallow them whole. Now, scientists have taken a closer look at these unusual fish and have found that they're far more adaptable and skillful target-shooters than first thought.

"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, one of the researchers, in a news release. "It pays to be able to powerfully hit prey over a wide range of distances."

In order to better understand how good these fish are at shooting their targets, the scientists trained fish to hit targets ranging in height from 20 to 60 centimeters from a precise location. Then, they monitored the fish's jet production and propagation.

It turns out that the time needed before water masses up at the jet tip actually isn't fixed. Instead, the archerfish makes small adjustments in order to ensure that a perfect drop of water forms just before impact-essentially ensuring a water bullet. Not only that, but the fish achieves this by modulating the dynamics of changes in the cross section of their mouth opening. This actually mimics a human's ability to hit targets with a powerful throw.

"One of the last strongholds of human uniqueness is our ability to powerfully throw stones or spears at distant targets," said Schuster. "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 to powerful throws. It is remarkable that the same line of reasoning could also be applied to archerfish."

The findings reveal a bit more about this unusual species. Not only that, but examining how the archerfish precisely controls water could actually result in human-built nozzles modeled after the fish.

The findings are published in the journal Current Biology.