Do fish sleep?

Fish do not sleep like humans and other mammals do.  First of all, most fish, with the exception of sharks, do not have eyelids and even sharks can’t close their eyelids.  All animals need rest however, and this is just what fish do – they rest.  There are so many types of fish and this means that there are many different ways that fish rest, but they do.  Some float motionless, some wedge themselves between rocks or burrow into the mud or even make a nest.  Basically, however they do it, fish do take time to “shut off” their brain, even though they stay alert for danger.