Archerfish are remarkably accurate in their shooting, adult fish almost always hitting the target on the first shot. They can bring down an insect six feet above the water's surface. This is partially due to their good eyesight, but also because of their ability to compensate for the refraction which occurs when light travels through water. They do this by swimming directly under the prey, where the distortion is the least.
When their prey is spotted, the archerfish sticks its snout just above the surface and squirts a jet of water at its victim. It is able to do this because of the narrow groove it has at the top of its mouth. It presses its tongue against this groove to form a narrow channel, then contracts its gill covers to force a powerful jet of water through the channel.
The resulting jet of water can be up to 2-3 m long, but their accuracy only allows them to shoot insects 1-1.5 m away. If the first shot does not knock the victim into the water, the archerfish will keep trying. Young archerfish start shooting when about 2.5 cm long, but are inaccurate at first and must learn from experience.
Anthropomorphism at it's finest.
Or die trying... a perfect example of natural selection.
The ability to hit the target from an angle could easily have developed in small adjustments: the fish initially just does it vertically (90deg), where no refraction occurs, then learns to do it at 88deg, where there is a very small error, then 86deg and so on.
In other words, through trial and error, each fish discovers the wisdom of the Dicta Boelcke that "In any type of attack, it is essential to go for your opponent from behind" and learns to go for the bug's "Six O'Clock" rather than trying to do fancy deflection shooting that usually ends up as a miss.
Well, there again, it is Darwinian survival of the fittest. Because there must have been a fish 7,201,555,124 years, 153 days, and 12 hours ago who could only shoot 999mm. He/she could not get the bug, so he died. So evolution wins again. ;)