archerfish, fish recognize faces, fish intelligence, fish brain, fish memory

The archerfish usually reserves its impressive spitting skills for knocking insects into the water. But a team of scientists at Oxford University, headed by Dr. Cait Newport, conditioned eight archerfish to spit at the image of a human face. By doing this, the team hoped to determine whether archerfish can distinguish one human face from another.

At first, when the fish succeeded in spitting at a human image on a screen, the scientists awarded them a food pellet. Then once the fish were conditioned to spit at the face, the real test began. The scientists mixed the familiar face into a lineup of 44 new ones, and more than 80 percent of the time, the archerfish spat at the correct face.

Dr. Newport explained to the Daily Record that telling human faces apart is a “surprisingly difficult task,” because they share so much in common. Thus, distinguishing human faces requires attention to subtle details. The Washington Post reports that humans are able to distinguish faces thanks to a brain structure called the fusiform gyrus. Other animals capable of recognizing human faces, such as birds, have the same structure. Fish, however, do not.

Researchers cannot yet be sure, then, how the archerfish managed to tell the faces apart. Dr. Newport also told the Washington Post that “we may even find that fish aren’t able to do it in other conditions”—recognizing a face on a screen is not the same as recognizing it at a variety of angles, and under a variety of lights, as humans can do.

So, the old saying that fish have only 3-second memories may be false. But whether that wily trout that always ignores your flies can recognize you from other frustrated anglers remains to be seen.

Photograph courtesy of James St. John/Flickr