Don’t diss this fish, which can recognise different human faces and will spit at them, too

Archerfish are already stars of the animal kingdom for their famous trick - they shoot high-powered water jets from their mouths to stun prey, making them one of just a few fish species known to use tools.

But by training Toxotes chatareus to spit at certain human individuals, scientists have shown that the little guys have another impressive skill: they seem to be able to distinguish one face from another, something never before witnessed in fish and spotted just a few times in non-human animals.

The results, published Tuesday in the Nature journal Scientific Reports, could help us understand how humans got so good at telling each other apart.

It’s generally accepted that the fusiform gyrus, a brain structure located in the neocortex, allows humans to tell one another apart with a speed and accuracy that other species can’t manage. But there’s some debate over whether human faces are so innately complex - and that distinguishing them is more difficult than other tricks of memory or pattern recognition - that this region of the brain is a necessary facilitator of the skill that evolved especially for it. Birds, which have been shown to distinguish humans from one another, have the same structure. But some researchers still think that facial recognition might be something that humans learn - it’s not an innate skill - and that the fusiform gyrus is just the spot where we happen to process all the necessary information.

That’s where fish come in. They don’t have anything like this structure within their relatively simple brains. But they’ve been trained to spit at particular shapes or colours before, so Cait Newport, Marie Curie research fellow in the department of zoology at Oxford University, wanted to see whether faces posed a particular challenge for fish brains.

And based on the spits she monitored, they don’t.