Manta Cognition and Behavior

The Mirror Test

The "mirror test" was developed in 1970 to measure whether an animal has self-awareness and self-recognition. To administer the test, a mark is applied to the animal so it is visible to them in a mirror. A mirror is made available to the animal and they are monitored to see if their behavior changes in a response.

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Only a few species have passed this test including some apes, the African elephant, the magpie, and the bottle nose dolphin. The common characteristics of these species are the relatively large, well developed brain and highly social behavior.

 

How do we know if a species can "pass" the mirror test?

To pass the test, the animal must repeatedly exhibit a behavior indicating self inspection.

For example, bottle nose dolphins made unusual turns in front of a mirror and blew bubbles! 

 

Dr. Csilla Ari thought if manta rays have the largest brain of all fish (more info here), then they probably have the best chance to pass the mirror test of any fish. She exposed captive manta rays to a mirror and experienced something unexpected.  The manta rays not only spent much more time in front of the mirror, but they exposed their belly to the mirror repetitively and even created bubbles somehow, similar to what was observed with dolphins.

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Phase 2 of this test has not been completed, so we cannot conclusively state that manta rays have self recognition, though they certainly exhibit some interesting  behaviors!