Katniss Everdeen’s got nothing on the banded archerfish (Toxotes jaculatrix). These are the real Hunger Games: if you don’t shoot your prey down with razor sharp precision, you don’t eat. Period.
Scientists have known for about 250 years that the banded archerfish has the ability to form a stream of water in its mouth to “spit” at its prey. Over time, they learned that the archerfish can do this by forming a tube with its tongues pressed against the groove on the roof of its mouth.
However, recent findings say there is more to the story than this. The researchers who studied this spitting phenomenon found that while the water stream leaving a banded archerfish’s mouth starts travelling at about two metres per second, the back-end of the stream picks up momentum, pushing the head-end forward. This packs a real punch when it makes contact with the prey – and it all happens in a fraction of a second.
Unlike other animals, like chameleons that use special internal structures to make their tongues more powerful, the researchers note that the banded archerfish uses an “external mechanism for the amplification for muscular power, just like an archer does with his bow,” which makes its species name all the more fitting. FYI – the first part of this fish’s scientific name “Toxotes” means “archer” in Greek.
The precision with which banded archerfish are able to “shoot down” their prey is astounding. They are able to compensate for visual refraction (the bending of light through the water) using their binocular vision, though this is something that has to be practiced – it’s not a skill they are born with.
Katniss’s Hunger Games takes place in the Capitol in the country of Panem. Banded archerfish, meanwhile, live in Indo-west Pacific mangrove swamps where they prey on insects crawling along overhanging vegetation. And unlike Katniss’s Hunger Games, which has an eventual end, a new Hunger Games unfolds for these banded archerfish every single day.
Vailati, A., Zinnato, L., & Cerbino, R. (2012). How Archer Fish Achieve a Powerful Impact: Hydrodynamic Instability of a Pulsed Jet in Toxotes jaculatrix. PLoS ONE 7(10): e47867. doi:10.1371/journal.pone.0047867. Retrieved from http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047867
Watch the video below to see a banded archerfish use its spitting power (it’s in slow motion so you’ve got to be a little patient to see the action).