The water-pistol is a harmless toy for children, but apparently it can be a lethal weapon too. This particular species of fish makes use of water jets and the laws of physics to aim at and stun its prey.
The aptly named archerfish employs a unique process to hunt land based insects and small animals – it aims, spits, and stuns. It lurks under the surface of the water, waiting for unsuspecting insects to land nearby. Then, it spits out water jets at a great force, instantly killing the prey. The entire process takes just one-tenth of a second.
An archerfish can bring down insects as far as three meters above the water’s surface. Once it selects the prey, it rotates its eyes so that the prey’s image falls on a particular part of the eye. Then it presses its tongue against the groove on the roof of its mouth to form a narrow channel, and contracts its gill covers to issue a powerful jet of water through the channel. The power of this shot can be altered for prey of different sizes. The jet can be up to five meters long.