How the Archerfish Shoots Water at Insects

It lives underwater, yet it can strike an insect resting well above the surface. The archerfish turns its own mouth into a natural launcher, firing jets of water at prey on leaves and branches with remarkable accuracy.

How does the archerfish shoot water at insects?

The archerfish creates a narrow channel inside its mouth by pressing its tongue against the roof of its mouth. It then forcefully closes its gills and expels water in a focused jet, allowing it to reach insects beyond its aquatic environment.

If the strike succeeds, the prey loses its balance and falls into the water, where it is swiftly caught. Most remarkably, the fish does not rely on force alone: before firing, it must judge the direction, distance and position of its target.

Why is seeing beyond the water so difficult?

The main obstacle is light refraction. As light travels from air into water, it changes direction, making objects viewed from beneath the surface appear to be somewhere other than their true position.

For an animal that must hit tiny prey, this shift could lead to continual mistakes. However, the archerfish can adapt its aim according to the insect's position and the angle from which it is viewing it, compensating for the distortion.

How can the archerfish hit leaves and branches?

Before releasing a jet, the fish generally positions itself close to the surface and studies its target carefully. The more favourable the angle, the less pronounced the visual effect of refraction tends to be, making it easier to work out where the stream must land.

Several factors make this technique even more effective:

• The fish alters the direction of its shot according to the insect's apparent position.
• Staying near the surface helps it see prey on low leaves and branches more clearly.
• The jet is concentrated so that it reaches the target with enough force to knock it down.
• Experience improves accuracy, particularly when targets are seen at different angles.

Watch the video shared by the YouTube channel Facts of Living Beings, which shows an archerfish in action.

Is the archerfish born knowing how to do this?

This behaviour has a strong natural basis, although practice can improve accuracy. Young fish are more likely to miss, while experienced individuals can fine-tune their shots more effectively and select more advantageous positions before attacking.

This ability demonstrates that hunting involves far more than a simple reflex. The animal combines vision, mouth control and rapid responses, turning a small jet of water into a highly efficient catching tool.

Why does this ability attract so much attention?

The archerfish is striking because it solves a complex physical problem without leaving the water. It must spot prey in another medium, deal with the distortion caused by light, and then propel water with enough force and direction to bring it down.

The next time you see an insect resting on a leaf near water, picture the scene from this fish's perspective. While it seems to be merely watching, it may be calculating the perfect shot, ready to turn a detail of physics into a survival advantage.