The universally accepted test for self-awareness or self recognition is the ‘mirror test’ among the variety of species. Only a few, large brained species have passed it to date and it implicates high intelligence and highly developed social behavior. Animals without self-recognition show only social responses or interaction with their reflected image. In addition to these behaviors, animals with self-recognition begin using the mirror to inspect themselves….
The manta rays at the Atlantis aquarium were most likely the first manta rays exposed to the ‘mirror test’ which turned out to be a big adventure for them, as well as for us. The first difficulty was to purchase a big enough mirror for underwater use which can be still moved by one or two person. I was lucky enough to have Dr. Dominic D`Agostino helping me to accomplish this difficult task, who assisted me in many phases of this experiment.
Dr. D`Agostino is placing the mirror in the tank before starting the experiment
The mirror self recognition test has been applied on other large brained species, such as asian elephants, bottlenose dolphins, killer whales, great apes, even african grey parrots, but no fish species passed the test so far. I thought: which fish species would have the chance to pass such test other than the fish species with the largest brain?? I felt a bit concerned and ridiculous when we tried to place the huge mirror in the manta ray`s tank at the first time….what am I thinking, what will happen??? The visitors of the Aquarium stopped and looked at us with curious eyes asking questions continuously about what was going on.
The mirror is ready for the mantas to arrive
I did not really know what to expect but after spending so much time with manta rays in the wild and in aquariums my instinct told me it worth to try. But what we witnessed in the next half an hour it completely exceeded even my most optimistic expectations. The two manta rays which usually spent only a few seconds in that area of the tank where we placed the mirror, passing by, now did not want to leave and were continuously circling there for almost 30 minutes! We were making notes and recorded the event on video while I felt shocked about their response and could not take my eyes off of them to notice anything unusual.
Manta rays passing by the mirror
Of course, this was only the first step and there is a lot to do before we can really find out whether they are able to show self recognition or not, but this was absolutely a very promising start!
Manta rays front of a mirror
The next couple of days similar, incredible responses made this experience more and more exciting. In order to step into the next phase of this test I tried to replicate what has already been done on other animals but the applied mark did not stay on the mantas` skin long enough to be able to evaluate their response. So eventually some technical difficulties and the end of our time left this exciting question opened. If we ever have the chance to go back again we will try to finish these experiments and find out whether manta rays are comparable to dolphins or elephants in terms of their cognitive abilities.