Fish are not known for their intelligence, especially your pet goldfish, but new research into one particular species of spitting fish has shown that they can actually recognise our faces.
The archerfish – which was the focus of this particular study – is best-known as the fish that is able to spit jets of water from its mouth at high velocity to shoot down prey, and now it’s got a new skill to add to its repertoire.
The joint study from the University of Oxford in the UK and the University of Queensland in Australia has determined that this particular species of fish can, to a high degree of accuracy, learn and recognise faces despite lacking the sophisticated visual cortex of a primate.
Fish knew which face to spit at
As the research team led by Dr Cait Newport explained, it was generally accepted that primates were the only species with the brain power capable of determining complex facial structures, yet the archerfish is capable of discriminating one face from up to 44 new faces.
To determine that the fish were indeed able to recognise different faces, the study published in Scientific Reports saw the fish presented with two images of human faces and trained to choose one of them using their jets.
After this, the fish were then presented with the learned face and a series of new faces and were able to correctly choose the face they had initially recognised, reaching an average peak performance of 81pc in the first experiment and 86pc in the second.
‘The perfect subjects to test’
“Fish have a simpler brain than humans and entirely lack the section of the brain that humans use for recognising faces,” said Dr Newport about her findings.
“Despite this, many fish demonstrate impressive visual behaviours and therefore make the perfect subjects to test whether simple brains can complete complicated tasks.”
Despite previous claims that human face recognition could only be achieved by primates, previous attempts with other species had attempted similar experiments with birds, however, unlike fish, they are now known to possess neocortex-like structures.
Equally important to note is that we can now show that fish are able to recognise humans, despite there seemingly being no evolutionary need for them to do so.
“The fact that archerfish can learn this task suggests that complicated brains are not necessarily needed to recognise human faces,” Newport continued.
“Humans may have special facial recognition brain structures so that they can process a large number of faces very quickly or under a wide range of viewing conditions.”
Archerfish image via Shutterstock