It's not unreasonable to ask, " Do fish sleep ?" After all, when was the last time you actually saw one of these little swimmers taking a snooze?
It's hard to tell when a fish is sleeping because they don't have eyelids (or they lack ones that close, if in the case of sharks). But scientists know that, while they don't engage in deep sleep, fish rest, and some have some very interesting ways of doing it.
How Do Fish Catch Z's?
Fish don't sleep the same way that you, your dog — or any mammal for that matter — does. Most don't experience REM cycles (though research on zebra fish suggests they have similar brain activity to rapid eye movement (REM) sleep).
Still, scientists have observed that many species of fish rest . This is a period of restoration when their metabolic functi