(Mirror Daily, United States) – It seems like not all fish species have a three-second memory. The latest research has shown that archer fish have the ability to remember and distinguish human faces despite the fact that they do not have a visual cortex.
Scientists from the University of Queensland and University Oxford engaged in a study to establish how archerfish would react after seeing many human faces. The experiment involved four archerfish. This species is a few inches long and has a prominent jaw which makes it capable of launching sharp blows of water, similar to bullets to hunt its prey consisting of insects.
Furthermore, the water shot is ten times stronger than the insects’ adhesion to the branch. Therefore, the perfect aim is the key. Scientists established the fish remembering ability by training them to spit jets of water at some faces they recognized. After reaching an impressive number of over 44 new faces, the fish could still distinguish the familiar ones, performing with an accuracy of 81 percent.
In the second experiment, researchers used four other fish and made it more complicated by adjusting color, head shape and brightness to look the same. However, the four specimens proved to have a spectacular accuracy of 86 percent by remembering the faces even better.
In addition to this, fish can do that without having a neocortex like us. According to Cait Newport, lead author from the Oxford’s department of zoology, the neocortex is the outer layer of the brain responsible for higher-order mental functioning. However, even if they have a simpler brain, these specimens surprised every scientist with their outstanding visual memory.
Even more interesting it’s that these fish could also distinguish faces that were in black and white with the standard head shape. Plus, experts have not identified yet how these fish were able to remember so many faces with such high accuracy. Higher-order visual recognition has only been demonstrated in birds until recently. Nevertheless, birds have neocortex structures as many domesticated pigeons proved during several studies.
Another question that raised the interest of experts is whether a complex brain is needed for face recognition ability. All in all, it is paradoxical that a small marine creature, such as a species of fish provided scientists with so much information.