Manta rays are first fish to pass the mirror test

摘要

Looking good. Giant manta rays have been filmed checking out their reflections in a way that suggests they are self-aware. Only a small number of animals, mostly primates, have passed the mirror test, widely used as a tentative test of self-awareness. 'This discovery is incredibly important," says Marc Bekoff, of the University of Colorado in Boulder. "It shows that we really need to expand the range of animals we study." Csilla Ari of the University of South Florida in Tampa filmed two giant manta rays in a tank, with and without a mirror. The rays showed no signs of social interaction with the image, which suggests they did not perceive it to be another individual. Instead, they repeatedly moved their fins and circled in front of the mirror. This suggests they could work out that their reflection moved when they moved. The frequency of these movements was higher when the mirror was in the tank (Journal of Ethology, doi.org/bdkr).