Now finally, it seems that we can all relax about finding Nemo, he should be able to find himself, according to a recent study. Apparently, fish can recognize themselves in photographs and in reflections.
Blue streak cleaner fish (say that in a hurry) were tested on whether they could recognize their own likeness in mirrors and whether they could distinguish themselves from other fish in photographs. According to the study, they can.
A joint study from the universities of Osaka, Japan, and Neuchâtel in Switzerland proved how fish are capable of identifying themselves.
Four different photographs were presented to the fish. One of the fish itself, one of a different fish, and two composites: one where the fish’s head was put with another fish’s body, and one where the fish’s body was put with another fish’s head.
The scientists then recorded the amount of aggression the fish fueled toward the images. Astonishingly, the fish showed almost no aggression towards the image of themselves and only slight aggression towards the image of their head on the other body.
On the other hand, the fish acted very aggressively towards the other fish and also towards the other composite image with the other fish’s head.
There has recently been increasing evidence demonstrating that fish can discriminate between familiar individuals based on facial characteristics (i.e., true individual recognition) and can even identify individual humans faces. The cleaner fish, Labroides dimidiatus, uses visual cues to identify between different individual members within social groups.
The study says that humans have a clear mental image of how they look, which allows them to recognize themselves in mirrors and in photos. It’s become apparent that more animals have this recognition ability, from great apes, Asian elephants, dolphins, horses, magpies, and now, cleaner fish.
It all goes to show that fish aren’t as stupid as we assume. The whole ‘memory of a goldfish’ may actually be a red herring, after all!