Natural Sharpshooter – Archerfish Uses Its Mouth as a Water Gun to Hunt Prey

The archerfish is famous for its ability to accurately shoot prey from several meters away with a powerful jet of water generated from its mouth.

Toxotes jaculatrix, commonly known as the archerfish, lives in the in mangroves of southern and southeast Asia, where they spend much of their time stalking prey from beneath the surface of the water, ready to hit it with a powerful jet of water, knock it out of the sky or whatever surface it’s sitting on, and then swallow it whole. The incredible accuracy of the arrow fish has long fascinated scientists, especially as studies have shown that it can adjust for various factors, like gravity, or the distance its target is at, to maximize its chances of success.

Archerfish hunt insects, spiders, or small lizards, remaining as still as possible with their mouths just above the surface of the water, ready to shoot their watery arrows at unsuspected victims. They will shoot at anything that moves or glows and are surprisingly accurate when targeting prey up to 2 meters away. This stream of water is also quite powerful, with one study reporting that getting hit in the face by it stings almost like an insect bite.

To generate a water jet strong and accurate to hit a small target hard enough to knock it into the water, the archerfish turns its mouth into a gun barrel by pressing its tongue against a groove in the roof of its mouth. When it’s ready to shoot, it compresses its gills to push the water out, and it continuously changes the shapes of its mouth so that the water stream will successfully aim and fire at prey.

Scientists also found that the archerfish also shoots the water at the end of the stream faster than it does at the beginning, which ensures that the squirted water slams into the target with maximum force, increasing the chances of knocking it off balance and into the water.

“I cannot think of a weapon developed by a human being which increases its velocity when it approaches the target,” Alberto Vailati, professor of fluid dynamics at the University of Milan, told the BBC. “That’s the most effective way to hit the target.”

Another study, which analyzed high-speed camera footage of both the fish and the stream of water, found that this natural marksman adjusts the way it shoots to make sure that it hits its target with the strongest jet possible, regardless of whether it’s a few centimeters from it, or two meters away.

Because their ammo is virtually limitless, archerfish are known to be very trigger happy, shooting their streams in several times, until the prey is knocked down or it moves out of range. Interestingly, archerfish only display their sharpshooting capabilities in the wild. Scientists have trained specimens to shoot at fake targets, as part of laboratory experiments, but they never displayed the same accuracy and power.