Do goldfish sleep?

Goldfish sleep when it is dark and they feel safe and stress free. Because goldfish have no eyelids, they sleep with their eyes open. They often settle at the bottom of their tanks and nestle near other objects.

Like most other animals, goldfish get tired and require rest to function normally. Pet goldfish, due to stress and their lack of eyelids, do not sleep well when their tanks receive light. So, tanks and aquariums should be medium-sized with plenty of hiding places and plants where the fish can hide away or swim through when tired or tense. Aquarium and room lights should also be turned off at about the same time each night.