? If the breeder does not observe carefully, it is generally difficult to distinguish whether the goldfish is sleeping or not. Because they have no eyelids, they keep their eyes open all the time. But when they sleep, they will be significantly quieter. Generally speaking, they sleep in two different ways:
1. Sleep in the dark: Watch the goldfish carefully. At night, they will hide in the dark and remain motionless. This is their normal performance of rest.
2, floating to sleep: There are also some goldfish in the sleep is floating in the water motionless, it is difficult to distinguish without careful observation.
? Other fish sleep in all kinds of strange ways, mainly in the following ways:
1. Sleep in the sand: Some fish will sleep in the sand at night, such as brocade fish, flower sea pig fish, etc., so that they can sleep quietly. It can also increase their sense of security.
2. Sleeping in bubbles: Some fish secrete a jelly-like substance that first blows out a big bubble when they sleep, and then they go in to sleep after the bubble hardens, leaving only a gap around their mouths, such as the Nanyang parrotfish.
3. Swim while sleeping: Sharks and tuna, for example, are constantly swimming while sleeping. So it's hard for humans to tell when they're resting and when they're awake.
