Most fish have no eyelids, so they cannot close their eyes. But does this mean that they are not sleeping? The question of whether or not the fish sleep is easy to confuse even the experienced owner of the aquarium, not like an ordinary person. Most often, this point is of interest to children, curious why. So how do fish sleep and do they sleep at all?
Oh, these stereotypes
It’s common for a person to close their eyes for sleep. So do animals. At the same time, it is advisable to be in the dark in a lying, relaxed position, although overworked people simply “turn off” in any position. But sleeping with open eyes is extremely difficult to imagine. Therefore, a stereotype of thinking is triggered: if it is impossible to close your eyes, then such a creature cannot sleep.
However, the inhabitants of the underwater world are completely different. Eyelids for humans and animals are needed in order to protect the eyeball from drying out. Fish are in the water, therefore, such a danger to them simply does not exist. Water moisturizes and cleanses the eyes of these creatures.
How do fish sleep?
You can understand that the fish went into a dream by the following signs: it froze in a thicket or other secluded place, hung in the water column. Some may even lie down, and some species prefer to rest on their side.
Most species of fish prefer to sleep in the dark, so if you go up to the aquarium and turn on the light, you can notice how its inhabitants return to a cheerful state, wake up. But there are those who rest during the day. These are predator fish, such as catfish.
However, a fish dream is not a condition that is meant by this word in people. How do fish sleep? For them, this is not a state of complete relaxation and unconsciousness, as we have with you, but rather a process of slowing down the functions of life. This allows the fish to activate very quickly if something dangerous or edible occurs nearby.
The phase of deep sleep, in which there is an almost complete loss of contact with reality, is absent in fish. Nevertheless, during sleep, the nervous system and other body functions are restored.
Do all fish sleep the same way?
Only fish that belong to the type of bone can hover in the water column and drift during sleep. They succeed in doing this thanks to the presence of a swimming bladder filled with air. The volume of air in this special organ determines how high the fish will be in the aquarium. The smaller it is, the deeper it will sink into the water column. Most residents of home aquariums are bone.
Stingrays and sharks are cartilaginous fish, they do not have a swimming bladder . How do fish sleep if they can't hang in the water? They are laid to the bottom or resting during movement. Cartilaginous fish are considered suitable for keeping in the aquarium cartilaginous antsistrusy and bots.
There are also underwater inhabitants who need to hide in a cave for sleep. Parrot fish sleep very unusual - almost under the covers. Only as it they use mucus, which is released by the fish through the mouth. Mucus envelops the carcass, creating a protective cocoon in which you can relax and not be afraid of anything. In the morning, the fish leaves its blanket.
Why do you need to know about the features of sleep in fish?
How fish sleep, it is important to know not only to satisfy their own curiosity, but also in order to provide the fish with comfortable living conditions. Like people, they don’t like it, if they violate their regime, they can suffer from insomnia, therefore:
- Be sure to turn off the light in the aquarium at night;
- pick up the fish so that they sleep at the same time of the day.
Pay attention to the fact that there are species of fish that sleep during the day and prefer thickets for this. If you put these in your aquarium, then in the daytime it will look empty and uninteresting.