A recent experiment conducted by researchers from the University of Oxford and the University of Queensland has confirmed that archerfish (Toxotes jaculatrix) have the cognitive ability to distinguish between human faces. In the experiment, the fish were able to pick a face that they had previously learned from 44 different example faces. Me? I can't distinguish between any human faces and always yell "Intruder!" and attack my roommate with a baseball bat whenever he comes home.
In the study, archerfish--a species of tropical fish well known for its ability to spit jets of water to knock down aerial prey - were presented with two images of human faces and trained to choose one of them using their jets. 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 learned to recognize. They were able to do this task even when more obvious features, such as head shape and colour, were removed from the images.
The researchers found that fish, which lack the sophisticated visual cortex of primates, are nevertheless capable of discriminating one face from up to 44 new faces. The research provides evidence that fish (vertebrates lacking a major part of the brain called the neocortex) have impressive visual discrimination abilities.
Cool, so fish have greater cognitive abilities than we previously thought. Why didn't you just tell us this, Aquaman? Why are you keeping secrets? Where is Atlantis? Come on, at least point me towards a shipwreck with some gold. So yeah, fish can recognize faces. Now if only fish could talk we could hear them say, "Great, here comes that @sshole who always taps on the glass."
Keep going for a video of the fish spitting at faces.
Thanks to Carmen, who agrees it's only a matter of time before fish are allowed to identify criminals in a police line-up.