An archerfish is a type of fish native to Asia and Australia that preys upon insects by shooting drops of water from its mouth. Its aim is surprisingly accurate, and research has shown that it has complex visual processing abilities. There are only a few known species, all of which belong to the Toxotidae family. They are sometimes kept as pets.
Archerfish, also called spinner fish, live in many different environments in southeast Asia, northern Australia, and India. They mostly prefer saltwater or brackish water, but are sometimes found further inland in freshwater streams. Most species are relatively small and narrow-bodied and have black lines or spots to compliment their silver or light brown coloring. They are generally under 6 inches (15.2 cm) in length, though a few have been known to reach over a foot (30.4 cm) long.
These little fish earned their archer moniker based on their unique method of hunting prey much like an archer shooting an arrow. The fish may hunt individually or in groups, and commonly attack insects perching just above the water on leaves or blades of grass. The attacking fish shoot drops of water at the unsuspecting insect, which falls to the water and is eaten. They can accurately predict where their prey will land and may leap from the water to swallow the insect.
As hunters, these fish are surprisingly accurate and can hit targets as far as 3 feet (91 centimeters) above the surface of the water. Their grooved mouths and powerful jaw muscles can project a stream of water 10 feet or more. Some species are capable of firing up to seven times if their first shot wasn’t on the mark.
Research has shown that this type of fish has very advanced abilities when it comes to vision. One study found that they possess an ability known as object orientation saliency, which means they could more easily see objects when they had a different orientation than the background. This ability was previously thought to be exclusive to mammals. Another group of researchers were able to train archerfish to hit moving targets. Amazingly, some of the fish were able to learn this ability simply by watching other fish who had been trained.
There are fewer than ten known species of archerfish, which are grouped into the Toxotidae family. Some, like the banded archerfish (Toxotes jaculatrix) and spotted archerfish (Toxotes chatareus) are caught and eaten by humans. One species discovered in 2004, Toxotes kimberleyensis or the Kimberley archerfish, lives exclusively in freshwater environments in Australia.
Archerfish are sometimes kept as pets, but their unique feeding habits can make properly caring for them difficult. They are omnivores, so they can be fed both live insects or dried seaweed. In tanks, it is generally recommended to group fish of the same size together, as larger fish can pick on or even eat smaller ones.