(Photo: Makuahine Pa'i Ki'i)
Perhaps, to the fish in your aquarium that you love, you're not just a Thing Which Provides Food. Perhaps you're a specific Thing Which Provides Food.
Researchers at the University of Oxford and the University of Queensland found that archerfish (Toxotes jaculatrix), like the one pictured above, is capable of distinguishing between human faces. This is a remarkable discovery, as it was previously thought that fish lack the cognitive abilities necessary. Phys.org reports:
First author Dr Cait Newport, Marie Curie Research Fellow in the Department of Zoology at Oxford University, said: '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. 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. If you consider the similarities in appearance between some family members, this task can be very difficult indeed.
'It has been hypothesized that this task is so difficult that it can only be accomplished by primates, which have a large and complex brain. The fact that the human brain has a specialized region used for recognizing human faces suggests that there may be something special about faces themselves. To test this idea, we wanted to determine if another animal with a smaller and simpler brain, and with no evolutionary need to recognize human faces, was still able to do so.'
-via Dave Barry