The amazing Archerfish nabs its prey by shooting jets of water into the air with its near perfect aim

The shooting technique used by archerfish stands out among the myriad strategies animals have developed for capturing their food, including spiders' sticky webs for catching insects and certain turtles' exhibition of a phony delicious morsel in their teeth. The small archerfish, which is sometimes referred to as the "anti-aircraft gunners" of the aquatic world, has evolved such perfect eyesight and fine control that it can fire down flying insects by spitting out a jet of water from a distance of several feet. After that, the insects drop into the water, where they may be quickly consumed. It has renowned accuracy in shooting. Despite having to adjust their aim for the refraction of the water's surface they fire through, studies have shown that archerfish nearly never miss their target, according to NBC News. 

Apparently, after mistaking the lighted end for a shining bug, legends from their native India claim that they could put out the cigarette of a visiting Englishman who came too close to a river or pond. However, experts have long been baffled as to how archerfish might have acquired such a peculiar characteristic. Based on recent research, it evolved from the underwater jets their ancestors used to sweep away sediments in search of food plants. And it demonstrates how even the most extreme natural behaviors may come about as a result of common evolution. Matthew Girard, an ichthyologist at the Smithsonian Institution in Washington who started the research while pursuing a Ph.D. at the University of Kansas, stated, “We knew about this behavior, the spitting mechanism. It was a question of, how did that evolve? What happened that led to something so incredible?”

Girard is the principal author of a paper that characterized the archerfish's firing mechanism and made an effort to explain how such a characteristic would have developed. It was published last month in the journal Integrative Organismal Biology. Girard and his colleagues discovered that there are at least nine different species of archerfish, even though just two are well-known as common aquarium pets by collecting fish specimens and tissue samples from museums and other institutions throughout the world. They discovered that all of them had the ability to spray water jets at insects, seemingly by focusing the water inside of a "blowpipe" structure they create in their mouths consisting of a combination of bones and soft tissues.

The question of whether the precise water jet produced by archerfish is created by a blowpipe structure like this one or a "pressure tank" structure in the fishes' mouths has been debated for over a century, noted Girard, and the latest research supports the blowpipe explanation. The researchers also examined closely related species, including the Pacific Ocean fish known as beach salmon, which is a member of the archerfish's "sister group." They discovered that beach salmon also possessed the requisite skeletal and cellular structures, but they weren't employed by them in the hunt for food. 

Modern archerfish frequently inhabit areas with vegetation that hangs over the water's surface, such as mangrove forests, and it appeared that in these conditions, the archerfish had evolved its shooting ability, he said. “There’s an abundant food source there,” he said. “Insects are some of the most abundant things on Earth, and they took advantage of that.” Although she has researched archerfish behavior, Wake Forest University biology professor Miriam Ashley-Ross was not engaged in the most recent study. “It’s a pretty ambitious study,” she said in an email. She added, “It would be great to know if there are similar mouth morphologies in the widely separated fish taxa that can all make underwater jets.”