OXFORD, England, June 7 (UPI) — If you’ve ever reeled in a fish and thought, “I’ve seen you before,” your catch might be thinking the same thing.
For the first time, researchers have documented a fish species capable of recognizing human faces. In a recent study, banded archerfish, Toxotes chatareus, were able to distinguish between human faces with a high degree of accuracy.
“Being able to distinguish between a large number of human faces is a surprisingly difficult task, mainly due to the fact that all human faces share the same basic features,” Cait Newport, a zoologist at Oxford University, said in a news release. “All faces have two eyes above a nose and mouth, therefore to tell people apart we must be able to identify subtle differences in their features.”
Newport is the first author of a new paper on the research, published this week in the journal Scientific Reports. The research was carried out by scientists from Oxford and the University of Queensland in Australia.
Archerfish are named for their ability to spit a fine jet of water at flying and hovering prey, knocking them onto the surface where they can be eaten.
As part of the study, researchers trained several archerfish to spit water at one of two faces. The fish were then presented with the learned face within a series of new faces. The specimens spit at the learned face 81 percent of the time. When facial features like brightness and color were standardized, the success rate went up to 86 percent.
When correct, the fish continued to spit at the learned face, proving their choice was not a coincidence.
“Fish have a simpler brain than humans and entirely lack the section of the brain that humans use for recognizing faces,” Newport concluded. “Despite this, many fish demonstrate impressive visual behaviors and therefore make the perfect subjects to test whether simple brains can complete complicated tasks.”
