Fish appear to not have eyelids. so my question is, do fish sleep, or are they always awake

Question

Fish appear to not have eyelids. so my question is, do fish sleep, or are they always awake

Answer 1

Yes.  Not all animals sleep the way humans do.  For example, horses and cows often rest while standing.  

Sleep is a function of the nervous system; it works independently of the eyes.  Humans naturally close their eyes to protect them while unconscious so that debris does not fall in.  

Answer 2

My fish sleep.  The swim really slow and plus some fish do come out when it's dark out.  Have you ever turned a light on near a fish tank in the dark and they get startled.

Answer 3

theyre like snakes. snakes dont have colored eyelids, but still sleep. fish do have eyelids, but theyre clear.