Do fish sleep in an aquarium?
What fish do in our aquarium during the day. we can see at any time. But what do they do at night when we sleep? You probably did not even think about it, but they are also sleeping. In fact, the biological functions of the body of the fish are very different from mammals. Because of this, the owners of aquarium fish are often not familiar with how the internal organs of their underwater pets work.
So, do the fish sleep? Yes and no. They “sleep” in their own way, in a way that is not at all familiar to us. That is, at the time of "rest" they produce a certain type of activity, which we call sleep. People spend in sleep on average eight hours a day. This is equivalent to about one third of a person’s entire life. For a person, sleep is the length of time in which our heart rate and breathing decrease, muscle relaxation occurs and a period of inactivity occurs. “Sleep” in animals is defined by the General Veterinary Dictionary, as “… a rest period during which physical functions are suspended and sensitivity to external factors is reduced”.
Thanks to expert zoologists, we can also know that different animals experience “sleep” in different ways. But in fish it occurs in a completely different way. Although, during the holidays, their perception of the environment is also significantly reduced.
Fish do not fall into a completely unconscious state in which they would completely cease to be aware of the world around them. The brain activity of most fish remains virtually unchanged, which means that they are not able to fall into sleep R.E.M (deep sleep). During its “sleep” the fish usually drifts without active movement at the bottom of its aquarium and instantly returns to its normal state with the slightest impact of any external factor.
I have noticed many times that my aquarium dwellers can stay for a very long time with little or no movement, only barely perceptibly shaking their tails. But once someone gets close to the glass, not even touching it, not turning on the light or anything else, they come to life and begin to swim around the whole aquarium again, as if “I was heading there”.
Certain species of fish have special periods in the cold season, when they “hibernate,” which of course differs from the usual understanding of this term. But still. This cycle of “sleep” is accompanied by the inaction of the fish, a decrease in metabolic processes in its body, a slowdown of all physical functions.
Although, again, this is different from the inaction that animals or humans are capable of. During this period, the fish either hide, or stay for a while in the lower layers of their habitat. at the bottom of the aquarium or pond (when it happens in the wild).
There are some fish that hibernate during the summer. It helps them protect themselves from dehydration. This is a very interesting phenomenon, as it actually allows the fish to survive outside of water during droughts or simply too high temperatures.
In Africa, there is even a kind of fish that turns into a kind of “cocoon” of mud and spends several months in it in a state of complete rest. Aquarium fish rarely resort to such methods of self-preservation, but may well remember them if their habitat conditions require it.
How to sleep aquarium fish?
Watching the fish in the aquarium, you might think that they never rest or sleep. In the understanding of man, they are in constant motion. However, like all representatives of the animal world, in fish, periods of active behavior are replaced by phases of slowing down of physical functions. this is the dream of fish.
Sleep fish is different from our understanding of sleep. Features of the structure and habitat do not allow the fish to fall into a state in which they would be completely disconnected from the surrounding reality. In this state, most mammals are immersed during sleep. In fish, however, during sleep, the brain activity remains unchanged. they are not able to fall into a state of deep sleep.
Such a feature can cause the question: how do aquarium fishes sleep?
Studying the behavior of aquarium fish, you can see that at certain periods of time the fish are practically without movement, dying in the water. This is the sleeping fish. During sleep, the fish usually drift without active movement. But the slightest impact of the external factor leads the fish to the active state.
Some fish can hide or be at the bottom of the aquarium. Many species of fish are fixed on the algae during sleep. There are breeds of fish that fall into a kind of state, similar to hibernation: at this time all the physical processes in the body of the fish slow down, and the fish are inactive.
In the sleep state of the fish, different hemispheres of the brain continue to work. Therefore, despite the slowness of the processes, the fish remains conscious. At the slightest danger, the fish can become active.
Answering the question whether the fish are sleeping, you need to take into account the difference in the understanding of sleep in fish and other animals. Most of the fish remain active, slightly slowed down, but conscious. They quickly go out of sleep at the sight of danger or when approaching suitable prey. In fish, there are periods of activity and rest, but the fish are not unconscious, like other animals.
It hinders to see that the fish are sleeping, and that they cannot close their eyes. Fish have no eyelids, so their eyes are always open. The eyelids are not needed by the fish, as the water itself cleans the surface of the eyes of aquatic creatures.
Each breed has its time to sleep. Some fish (mostly predators) sleep during the day and awake at night. For example, catfish hiding during the day, and at night they are actively hunting.
Can fish sleep in an aquarium?
Most recently, I already wrote about the fact that we purchased aquarium fish and now Katya is carefully watching their life, and this raises additional questions from her side. Once, before going to bed, she asked me if the fish were sleeping in the aquarium. Interesting, right? I myself have never thought about it, and I also became very interested in whether they needed a rest.
We began to watch the fish at different times of the day. And that’s what they found. When someone is in the room, moving or talking, the fish also actively swim, chase each other, swim closer to the walls of the aquarium and watch what is happening around.
When there is silence in the room and there is no one for a long time, then if you quietly enter and observe them from afar, you can sometimes notice that they seem to hang in one place and are almost at the very bottom. But it is necessary to come closer as they come to life and again begin to swim throughout the aquarium.
Well, my daughter and I began to look for more information about whether the fish are sleeping and that’s what we learned.
Fish do sleep, but not at all in the way we used to imagine. Fish are never unconscious, and do not fall into a deep sleep. During their sleep, the fish seem to drift, without any active movements. But it is necessary to appear external effects, as they return to their normal state. It was this state that we and our daughter managed to “catch” several times.
By the way, the fish never close their eyes, which also does not allow to see their sleep, in the form in which we are accustomed to perceive it. Fish have no eyelids; they do not need them. The eyes of fish are cleaned by the water in which they swim.
Different fish species have a certain time to sleep. Some fish sleep during the day, while others sleep at night.
And the fish can fall into a "winter" or "summer" hibernation. During the cold period, the activity of some fish decreases and all its physical functions slow down. At this time, some fish remain at the bottom.
During heat or when conditions in the aquarium change, fish can also be at the bottom to allow them to survive under unusual conditions.
With the advent of new inhabitants, we are learning with the whole family something new and interesting. And what interesting facts did you learn about your pets?
Do fish sleep?
Prophet fishermen and owners of aquariums ask the question: Does the fish sleep? The question arises for good reason, because no one saw the fish with eyes closed. They just have nothing to close. the fish have no eyelids. They do not rest in the same way as it is common in humans, birds and mammals.
Fish sleep is a resting phase in which all functions slow down, the body becomes immobile, reactions are weakened. Some fish at the depth do not react to external stimuli (you can touch them, shine a flashlight in the eye). Others feel the slightest danger. Many fish become almost immobile while resting. And some (tuna, sharks) are constantly in motion, lying down on the water against the stream. If water does not pass through their gills, they may suffocate.
Features of the rest of different types of fish
The specifics of the rest of the fish depends on their variety. So, astronotus lie on the bottom or hang upside down. Clown fish stacked on the flank at the bottom of the aquarium. Other species just hang still.
How do fish sleep in nature?
Cod. lying, flounder buries in the sand, herring. up the stomach, drifting in a stream of water. Most fish seek out for their nooks and places — among rocks, crevices of rocks, algae and corals.
Not all fish sleep at night. Night predators (burbot, catfish) prefer daytime sleep. But after a hectic night, a fish with a daytime lifestyle can afford a “quiet hour” during the day. Dolphins have surpassed all (although these are not fish, but mammals). They practically do not sleep. While the hemispheres are resting, their brains are awake alternately so that they can float to the surface and inhale the air. The rest of the time, both hemispheres work. In general, the peculiarities of fish rest depend solely on their species.