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 ...

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 mirror to make sure they're big enough. This ...

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

Cleaner wrasse quickly learn to recognize themselves in mirrors, and take advantage of the information their reflection provides. They also experiment with the mirror in a way we might call playful, ...

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 ...

Cleaner wrasses (Labroides dimidiatus) thrive in coral reefs around the world. But they’re more than just another pretty face among the brightly colored marine ecosystem. Despite their diminutive size ...