BBC: Archerfish, found predominantly in the western Pacific Ocean, were named for their unique ability to prey on land-based insects and small animals by shooting them with water spewed from their mouth like a water pistol. Although it had long been assumed that the fish must have specialized internal organs to be able to shoot water with such force, new research by a team at the University of Milan shows that the fish instead modulate the water velocity by closing their gills and changing the shape of their mouth to resemble a gun barrel. Thus they can “shoot water jets up to six times more powerful than their muscular strength,” writes Michelle Warwicker for the BBC. The researchers liken the effect to that of a drop-on-demand inkjet printer.