Well I sleep with my eyes open anyways so I guess I dont sleep I just rest. =D
I catch my fish "resting" all the time at night. I can see them on the bottom not moving. As soon as I turn the lights on in the morning they swim all over. Saltwater fish imo are easier to see "rest" My ex bf had a tank with percs, a hippo tang, and more and everynight when he turned off the lights the percs would fan the sand away so there was a hole and theyd lay on the bottom, and the tank would go in a cave. Sooooooo cute.