A species of fish that look like peaceful swimmers are as accurate as sharpshooters at killing their prey. The only difference is the archerfish spit water rather than dodging bullets. Scientists have found that the archerfish’s spitting ability was far more remarkable than previously thought. According to a new study published in the journal Current Biology, archerfish is the first known tool-using animal that can change the hydrodynamics of a free jet of water.
This big-brained fish can hit targets up to 24-inch away
The fish can be found in the open ocean and in the water bodies of India, Thailand, Australia and the Philippines. Stefan Schuster, co-author of the study, said even humans can’t spit as accurately as these water-shooting fish. Of course, humans with talent for throwing objects such as spears or stones at distant targets can be compared to the archerfish.
To conduct the study, the University of Bayreuth researcher Stefan Schuster and his colleague Peggy Gerullis trained the big-brained fish to hit targets from a fixed position at a distance of 8-24 inches. As the fish attacked its prey, researchers monitored the jet propulsion and wave movement. Video and photo analysis revealed that the fish adjusts focus of their jets of water to ensure that a thick slug is formed exactly before the water jet hits the prey. It maximizes the harm on the unsuspecting prey at different distances.
The fish’s natural mechanism could inspire new water nozzle technology
Evolution of this skill in the fish was driven by a primary urge: hunger. Usually they shoot water on unsuspecting victims such as insects or little lizard on a twig above the water. The surprised victim falls off the twig and into the water, and then the fish gobbles it up. Archerfish’s technique could inspire new technologies for adjustable jets and inkjet printing, Schuster said.
Many industries ranging from manufacturing to medicine use adjustable jets. Water jet cutters, mixed with small abrasive particles, can even slice through granite or steel. The fish’s natural mechanism for controlling water could help scientists improve efficiency of water jet cutters.
