Scientists demonstrate how a species of tropical fish can recognise and differentiate between human faces, showing that fish could have better cognition than their tiny brains suggest. Matthew Stock reports.
Trying to prove that fish are smart seems like spitting in the wind. But scientists from Britain and Australia have shown they can differentiate between complex shapes and patterns. Some can even be trained to recognise human faces. This archerfish was shown two different images of human faces and trained to 'choose' one of them by spitting a jet of water at it. The tropical fish could recognise one out of 44 new faces up to 81 percent of the time This, despite lacking the part of the brain which other animals use for sophisticated visual recognition. (SOUNDBITE) (English) DR CAIT NEWPORT, MARIE CURIE RESEARCH FELLOW IN THE DEPARTMENT OF ZOOLOGY AT OXFORD UNIVERSITY, SAYING: "When you look at a picture of a fish's brain it's only got what we consider the primitive sections of the human brain which are underneath that highly folded neocortex. And yet fish are still able to perform really complex behaviours; they can do facial recognition as we showed, they also build social systems, and there's some evidence of potential tool use." This Picasso triggerfish was equally adept at choosing the black disc surrounded by white ones. Such fish cognition sheds light on their ability to recognise and return to the same territory year after year for breeding. (SOUNDBITE) (English) DR CAIT NEWPORT, MARIE CURIE RESEARCH FELLOW IN THE DEPARTMENT OF ZOOLOGY AT OXFORD UNIVERSITY, SAYING: "It is amazing what they can do with a really simple brain as humans like to call it. Although it seems a bit unfair to call it simple - I think their brains are perfectly adapted to what they do and that's what's important to remember about all this - brains can look different, but they've evolved for different tasks." The team says complicated brains are not essential, even for recognising subtle differences like in human faces. So, the next time you forget to feed your pet fish, the eyes glowering at you from the tank might know just who's to blame.