A new study published in Biology Letters found that wild fish could distinguish between two divers based on the colors they were wearing. The investigators began by training two species of wild sea bream (Oblada melanura and Spondyliosoma cantharus) to obtain a food reward from a diver by following them. They then had two divers enter the water wearing different colors and found that the fish were able to tell them apart when they wore different gear (e.g. different shaped facial gear, different colored flippers). However, when the divers wore identical gear, the fish could not tell them apart suggesting they used visual cues such as color or shapes to differentiate them.
While the sea bream used colors and shapes as visual cues, other species of fish have been found to recognize human faces as shown in this earlier study from another research group:
If you happen to own fish, do you think they recognize you specifically?
Sources
M Tomasek, K Soller, A Jordan. Wild fish use visual cues to recognize individual divers. Biology Letters. 21: 20240558, 2025. doi: 10.1098/rsbl.2024.0558
YouTube
Categories: Comparative Physiology
Life Lines by Dr. Dolittle 