Do you know that the fish here in Hawai‘i go to the dentist on a regular basis to have their teeth cleaned? From large sharks to young yellow tangs, they all get free dental work, but they must go to ...

A bluestreak cleaner wrasse (Labroides dimidiatus) swims in a tank at right, with its mirror image at left. Credit: Osaka Metropolitan University An Osaka Metropolitan University-led team has ...

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 ...

If you're not really into salt-water tanks or don't spend a lot of time in coral reefs, there's still a high probability you may have heard of the bluestreak cleaner wrasse fish. Likely because last ...

Researchers have demonstrated that bluestreak cleaner wrasse (Labroides dimidiatus) checked their body size in a mirror before choosing whether to attack fish that were slightly larger or smaller than ...

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 ...

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.

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, ...