Manta rays are impressive in so many ways, including how they coordinate hunting and have complex social interactions. And, did you know that the oceanic manta rays have the largest brain of all fish? Their large brain to body mass ratio is similar to mammals that have passed the mirror self-recognition test – a test that scientists developed to see if animals have a sense of self.
Researchers gave the test to two giant manta rays. They observed the captive manta rays approaching the mirror significantly more than other parts of their tank. When in front of the mirror, the rays behaved unusually, frequently blowing bubbles at the mirror, and flipping to expose their bellies. And they didn’t approach the image with the typical behavior of encountering a stranger. The scientists concluded that the mantas passed the test that is viewed as a prerequisite of self-awareness.