A new study published in the Proceedings of the Natural Academy of Sciences has shown that bluestreak cleaner wrasse (Labroides dimidiatus) recognize themselves in photographs (Kohda et al., 2023). The fish first showed that (like chimpanzees, dolphins, elephants, and magpies) they can recognize themselves in the mirror—as evidenced by moving their own bodies to better examine an unusual mark they can see on the body in the mirror. This is considered evidence of self-awareness.
Animals in the mirror test may understand that the image before them is a reflection of “me” because it mimics their own movements. This study, however, went one step further: Fish who recognized themselves in the mirror were subsequently shown photographs of themselves and other wrasse. The wrasse could apparently differentiate between the two: They acted aggressively toward photos of other wrasse but not photos of themselves. Additionally, they rubbed themselves after seeing a mark on photos of themselves but not on photos of other wrasse. We hope that this and other recent studies highlighting the mental abilities of fish compel lawmakers, scientists, and others to treat them with the care and compassion they deserve.