Archer fish can control the water jets they shoot from their mouths to nab prey from a variety of distances.

Credit: Stephen Dalton/Minden Pictures/Corbis

Peggy Gerullis and Stefan Schuster at the University of Bayreuth in Germany trained the fish (Toxotes jaculatrix; pictured) to fire at specific targets from defined locations. They then used a high-speed camera to film the animals as they shot at targets of different heights. They found that the fish adjusted the jets of water so that they were most focused and forceful just before reaching the target. For a target 60 centimetres above the water, the fish produced a jet that remained stable over a longer period of time — by opening its mouth more gradually — than when aiming for a target 20 cm above the water.

This ability is analogous to throwing in humans and could similarly have contributed to the evolution of cognitive skills in the fish, the authors say.

Curr. Biol. http://dx.doi.org/10.1016/j.cub.2014.07.059 (2014)