Question

does fish sleep and how

Answer 1

Yes! They are sleeping, and they can sleep at any time during the day or night. Fish do sleep with their eyes open, because they don't have eyelids (except for some sharks) to close! ... For fish, sleep is more like a resting period similar to a daydream that humans might experience.

Answer 2

Yes fishes sleep in water and when they sleep the float in water or remain on the ground surface below the sea