A shrimp scrap drifted down the face of a mirror, and a small reef fish tracked it like it was watching a slow-motion experiment. The fish, a blue-streak cleaner wrasse, had carried the shrimp upward, ...

Cleaner wrasse have revealed a remarkable new side of fish intelligence. Marked with fake parasites, they used mirrors to inspect and remove the spots—far faster than seen in earlier tests. Even more ...

Researchers at Osaka Metropolitan University in Japan have discovered a previously undiscovered behavior in cleaner wrasse (Labroides dimidiatus). When presented with a mirror, the tiny fish not only ...

Bluestreak cleaner wrasse are small, territorial fish that aggressively fend off intruders. But when they have access to a mirror, the fish size themselves up before deciding whether or not to fight.

See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. Before squaring up for a fight, some fish check themselves out in the ...

Cleaner wrasse picking parasites of a Fusilier fish. Underwater Macro Image taken scuba diving in Raja Ampat, Indonesia.© SergeUWPhoto/Shutterstock.com Cleaner ...

Controversial new research shows that a tiny, unsuspecting species of fish can pass a test that’s widely considered the gold standard of intelligence. As far as we can tell, only a few of the most ...

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. For decades, self-awareness has been guarded as a very ...