For the first time, researchers have found that wild fish can identify individual human divers using visual cues.

In a study published in Biology Letters, researchers trained saddled sea bream and black sea bream to follow a diver for food. The fish quickly learned to distinguish between two different divers when they wore different dive gear.

However, when both divers dressed identically, the fish could not tell them apart, suggesting they rely mainly on external appearance rather than facial recognition.

While some animals, like dogs and crows, can recognize individual humans, this study provides the first strong evidence that wild fish can do the same — at least under certain conditions. This has implications for marine research, conservation and ethical considerations in human-wildlife interactions.

It also suggests that fish cognition may be more advanced than previously thought.

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