Do fish sleep

Question
Do fish sleep?  If so, how and when?

Answer
Hi Jon;

Fish do sort of "sleep". Fish that normally like to be out and about during the day will rest and hide at night in the dark. It protects them from nocturnal predators. Fish don't have eyelids so they can't close their eyes. They just get very still and rest. Fish that are nocturnal, meaning they are active at night, will rest and hide during the day instead.

At Your Service;
Chris Robbins