Do most fish sleep at night?
While fish do not sleep in the same way that land mammals sleep, most fish do rest. Research shows that fish may reduce their activity and metabolism while remaining alert to danger. Some fish float in place, some wedge themselves into a secure spot in the mud or coral, and some even locate a suitable nest.
How do I know if my fish is sleeping?
It’s pretty easy to tell when fish are sleeping: they lie motionless, often at the bottom or near the surface of the water. They are slow to respond to things going on around them, or may not respond at all (see some sleeping catfish here). If you watch their gills, you’ll notice they’re breathing very slowly.
Do fish stay still asleep?
Fish appear to be more alert3 than humans are during sleep, which may give them more time to react to potential threats in their environment. Still, fish do slow down metabolic processes in their resting state, much like humans. They physically slow down as well, with some fish floating in place.