Add Yahoo as a preferred source to see more of our stories on Google. A protective mucous cocoon surrounds this parrotfish as it sleeps in Australia's Great Barrier Reef. This layer of protection ...

Fish sleep in a "low power mode," maintaining basic functions like breathing, but they don't close their eyes. Providing a consistent light-dark cycle is essential for fish health, as they can ...

You’re staring at your aquarium. It’s late. Everything is quiet. And there’s your fish, floating calmly, fins moving slowly, eyes wide open. Are they... asleep? Or just zoning out? Fish don’t come ...

Fish don’t have eyelids. They don’t curl up in beds or snore, so it’s easy to assume they just keep swimming forever without rest. But they do sleep—it just looks very different from how we do it.

By tracking eye movements in zebrafish, researchers identified four different types of sleep, analogous to the complex sleep ...