Are fish aware of themselves? These fish recognize themselves in the mirror!

Are fish aware of themselves? Cleaner fish seem to recognize themselves in the mirror

Chimpanzees, dolphins, crows and magpies recognize their reflection as an image of their own body. So far, this is an indication that these species have a consciousness of themselves. Scientists from the Max Planck Institute for Ornithology in Radolfzell and the University of Konstanz and the Osaka City University have now discovered that cleaner fish also react to their reflection and try to remove patches on their body when they see them in the mirror. The results indicate that these fish have significantly higher mental abilities than previously thought. At the same time they are starting a discussion about how scientists can detect the intelligence of living things that are so different from humans.

In the classic mirror test, researchers mark the face or other parts of an animal's body with color spots. To pass the test, the animals must carefully inspect or specifically touch the marked area.

To test whether fish can recognize themselves in the mirror, the researchers examined the response of cleaner fish (Labroides dimidiatus) to a mirror test. Cleaner fish live in the oceans and feed on parasites on the skin of other fish. The scientists marked the fish in one place of the body, which they could only look at in the mirror. The test was considered passed when the fish rub the marked spot on a surface, trying to remove the paint.

In fact, the cleaner fish tried to remove the patches on their skin. The researchers provided the animals with spots, but did not give them a mirror, the fish did not respond to it, as well as transparent markings that were not visible in the mirror. Cleaner fish also do not try to remove supposed stains on their own bodies when seeing other tagged peers. They also do not react to spots directly on the mirror. "Through all these observations, we can rule out the fish instinctively reacting to parasitic markers in their environment. Only the sight of patches on the own skin therefore represents a charm for a cleaner fish, to which it reacts. The behavior of the cleaner fish fulfills all the criteria for a successful mirror test, "explains Alex Jordan from the Max Planck Institute for Ornithology and the University of Konstanz.

Test passed

Do the results now show that cleaner fish actually have an awareness of their own self - a trait that is as yet only attributed to some mammals and birds? Or are other skills needed to pass a mirror test than previously thought? "Our observations leave little doubt that this fish's behavior meets all criteria for a successful mirror test. It is less clear, however, whether one can conclude that fish are aware of themselves - even though in the past many animals had been given self-awareness after passing the mirror test, "says Jordan.

The argument that the behavior of the fish is not clear enough to speak of a successful mirror test would call into question the general credibility of the mirror test. Finally, the cleaner fish have behaved during the test similar to other animals with the same experimental setup. "The obvious explanation is that while the fish pass the mirror test, they are not aware of themselves. Rather, they recognize their reflection as an image of their own body, but do not understand what it means. So we need to critically examine the mirror test and consider whether it should continue to be used as a standard for self-awareness in animals, "says Jordan. (Pm)