They always seem to be swimming about and they never close their eyes, but that’s because they can’t as they have no eyelids but that dosent mean that they don’t sneak a rest from time to time though.

Some fish will perch below a sunken log or against a rock and nest for a while. Some sink to the bottom of the tank, which alarms people ( owner of fishes) because they think their fishes have dies. Not all can rest. Some fish have to keep moving to breathe. Sharks need to push water through their gills all the time by moving around, so they can never stop swimming. But they do slow down a bit to give their tiny brains a rest , they have been know to bump into objects , during this period they suddenly ‘Wake up’ and move in the opposite direction