A shrimp scrap drifted down the face of a mirror, and a small reef fish tracked it like it was watching a slow-motion ...

Cleaner wrasse have revealed a remarkable new side of fish intelligence. Marked with fake parasites, they used mirrors to ...

A small coral reef fish can recognize itself in a mirror. This discovery challenges long-held ideas about animal intelligence ...

Researchers at Osaka Metropolitan University in Japan have discovered a previously undiscovered behavior in cleaner wrasse ...

Before squaring up for a fight, some fish check themselves out in the mirror to make sure they're big enough. This strange behavior was seen in bluestreak cleaner wrasse (Labroides dimidiatus), who ...

Before deciding whether or not to fight another fish, cleaner wrasse check their own reflection in a mirror and size themselves up. First, Taiga Kobayashi at Osaka Metropolitan University in Japan and ...

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.

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 ...

Female cleaner fish are sensitive to what their partners can and cannot see while working on client fish. This means they may have theory of mind, a concept built on awareness of other’s perspectives, ...