They do it in a special way, and some even move in their sleep
Probably everyone knows the saying that fish sleep "with half a brain", and many believe that they don't sleep at all. However, in addition to the fact that logic does not allow us to reject the idea that every living thing on earth, even in water, needs sleep, you may have noticed how your fish "stands still", which could have scared you, or led you to the idea that she might be sleeping.
Fish sleep, but in a special way.
How fish sleep
There is a difference between human sleep and fish sleep. In humans, and mammals in general, part of the brain "turns off" during sleep, they enter the so-called REM phase and do not react to silent external events, which is different in fish.
Since they don't have eyelids, fish can't close their eyes, so they "perform" the rest phase with their eyes open as standard. During sleep, they calm down completely, slow down their breathing, metabolism and reduce their brain activity. However, most fish remain somewhat conscious during sleep and can see what is in front of them and react to the slightest changes in their environment.
It is also interesting that some species of sharks have to move during their sleep.
When the fish sleep
The sleep time of fish depends on the species to which they belong: some sleep during the day and some at night, with the fact that it is characteristic of aquarium fish that they are active during the day and rest at night.
Where the fish sleep
Just like all animals that are natural prey, fish hide at the bottom of the aquarium (especially in winter), crawl into corners or around stones and "charge their batteries" there.
Therefore, before you are afraid that the fish has crawled among the algae or in the decoration, check if it is just sleeping.
