Moby the Manta Ray and the Mirror Self-Recognition Test

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Manta Ray investigates itself in a mirror

My earlier posts ended pretty grim because I wanted to share how manta rays are being overfished. But today I just want to share one really cool fact about us manta rays. Did you know that manta rays have the largest brain/body ratio of any fish in the sea? Yup, that includes all other rays, elasmobranchs (sharks and rays), and any other fish you can think of. I’m surprised it took humans so long to figure that out, but it is not like we are the easiest of the marine animals to study.

There is one human, Dr.Csilla Ari, who is running experiments on two of my buddies living at the Atlantis Aquarium in the Bahamas. She recently put a large mirror into the manta rays’ tank to test their ability to recognize themselves. Self-recognition in a mirror has only been shown in very large-brained and “smart” species such as dolphins, higher primates, and elephants. In those experiments a mark is placed on the animals’ forehead, and when the animal sees themselves in the mirror they soon investigate the mark. Animals without self-recognition may charge at the “intruder” or show their normal social behavior towards another animal of the same species.

Unfortunately the mark that the scientists placed on the manta rays did not stay, but maybe in the future I should loan them some of the remoras that are forever stuck to me to use as markers! The two manta rays did spend a lot more time than usual in the area where the mirror was. They also blew bubbles in front of the mirror, which manta rays don’t usually do. They also turned their underbellies towards the mirror. It will be monumental when humans finally figure out how smart we manta rays really are!

Please visit Dr. Ari’s blog for more information on her research.