Fish Recognize Humans, Study Shows

BEACON TRANSCRIPTFish recognize humans, according to a new study. If you own a pet fish, chances are it’s happy to see your face just as much as a dog or a cat. You probably didn’t think fish can be that intelligent, but researchers have found that they can be trained to tell one face from another.

"Fish Recognize Humans, Study Shows"

The study was conducted by a British and Australian team of scientists from the University of Oxford in the UK and the University of Queensland in Australia. The research involved archerfish, a species of tropical fish. Investigators discovered that these fish have the ability to study and identify human faces with quite a high level of accuracy. This may sound like nothing to us, humans, but it’s not that easy. Scientists say that differentiating between countless faces is a hard task. Our basic features are very similar, and for an animal to tell them apart, it really is a big deal.

Prior to this discovery, it was believed only primates possess this ability. Primates have a large and compound brain, as opposed to fish, that do not have a neocortex.  This means that their brain lacks the section that humans and primates use for facial recognitions. Yet, their simple brain seems capable enough of performing complex tasks.

The experiment showed that fish recognize humans. Archerfish were up to 89 percent accurate in telling human faces apart. The team positioned a computer monitor above the aquarium and showed human faces on it. They trained the fish to recognize faces and rewarded them with food pellets when doing a good job. This way, the fish became quite good at telling people apart.

Archerfish spit a jet of water to knock down prey in branches above water. Researchers used this ability in the study. Once the archerfish learned how to tell faces apart, when showed the same face, they released the jet of water onto the monitor.

What’s more impressive is that fish were able to recognize faces even when some features, such as head shape or color, were taken out of the photos. This goes to show that fish recognize humans even though they do not possess a complicated brain. People tend to associate facial recognition with large and complex brains, but not anymore.