The rock-mover wrasse grows to be 12 inches long, but the babies look more like a piece of limu (seaweed) than a fish. The two-inch-long baby rock-movers have branching fins that grow out from ...

But now, incredibly, new research suggests that the cleaner wrasse—a tiny, tropical reef fish—can recognize itself too, making it the first fish to do so. Scientists have long used a mirror ...

Researchers at Osaka Metropolitan University in Japan have discovered that the 'cleaner' wrasse fish, Labroides dimidiatus, is able to recognise itself in a photo. The species is known to attack ...

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 ...

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.

The bluestreak cleaner wrasse is just one of about 600 different species of wrasse. It's a little thing, about 3.9 inches (10 cm) long on average, with, well ... a blue streak down its side.

An Osaka Metropolitan University-led team has demonstrated that bluestreak cleaner wrasse (Labroides dimidiatus) check their body size in a mirror before choosing whether to attack fish that are ...