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Many an aquarist will tell you that the beloved goldfish they've kept for ten years has no problem recognising who they are, or that their prized Oscar is always happy to see them. Despite what many may think about the intellectual capacity of our aquatic pets, there's plenty of anecdotal evidence out there to suggest that fish do in fact have the brainpower to recognise human faces. Now, thanks to a new study by the University of Queensland, the anecdotes might now be close to being backed up by scientific evidence.

The secret lies not in the fishes' brains as one might think, as they lack the neocortex that humans and other mammals use to power the skill of how to recognise faces. Surprisingly, the secret actually lies in their eyes - or rather, the ability of their eyes to perceive ultraviolet wavelengths of light.

The study showed that the ambon damselfish (Pomacentrus amboinensis) use UV light to detect a complex arrangement of facial patterns that are unique to each individual fish - fish that to us would appear to simply be yellow with a few spots. Using these patterns, the little damselfish can discriminate between the faces of their own species and those of a similar species, the lemon damselfish, and can even tell the difference between different individuals within their own species. The theory is that since ambon damselfish are social animals that live in groups, facial recognition may help them discriminate between individuals and thus better develop and maintain bonds.

The jury's still out on whether fish can recognize human faces, but based on their remarkable ability to choose between intricate patterns, it would come as no surprise to many fishkeepers if fish could actually differentiate between one person and another.