Fish sleep in an aquarium - we create conditions for sleeping. How do fish sleep in an aquarium? Do fish close their eyes when they sleep?

Looking at the aquarium at night, many families wonder when do the fish sleep? Do they sleep at all? This question interests many aquarists, because at any time of the day or night they see cheerful, active pets.

All living things on the planet have certain similarities, for example: when a person, animals or birds want to sleep, they take a lying position, relax and close their eyes, but looking at aquarium pets, it seems that they are always awake, and watch the events taking place around the clock, with open eyes . However, this is a misconception; aquatic inhabitants swim and do not lower their eyelids due to their absence; this is an anatomical feature of most aquarium fish.

In fact, fish also have phases of active wakefulness and sleep. People, animals, and birds use their eyelids to protect their eyes from drying out, but this is not possible for waterfowl pets, because they are constantly in the water, and the aquarium liquid cleanses and moisturizes their eyes well.

How to tell if a fish is sleeping

To understand whether a fish is sleeping, you need to look at its behavior. If it is in an immobilized state, hiding in algae or hanging in the water column, barely moving its fins, this means that the aquarium pet is in the metabolic stage. There are also some aquatic inhabitants who prefer to sleep on their sides, at the bottom of the aquarium.

Aquarium inhabitants, like all living things on earth, prefer to sleep at night. If you suddenly enter a dark room and turn on the light, you will notice how the fish perk up, begin active swimming, and wake up. And that is why for fish living in aquariums you need to turn off the lights at night. But certain species of aquatic inhabitants are not accustomed to this way of life. - catfish will not refuse to sleep during the daytime.

It is worth noting that the physiological characteristics of fish differ from human ones. During fish sleep, the aquarium inhabitant does not relax, but is in full consciousness, reducing its functionality. Therefore, when a person throws food into the aquarium, there is a danger to life, the fish suddenly becomes more active, resumes vital activity and lives its usual life.

For aquatic inhabitants, sleep does not represent a complete disconnection from reality, but only slows down physical activity. However, such sleep allows the fish to restore the functionality of the body and nervous system.

Classification of fish by sleep

Aquarists conducted a thorough analysis of the behavior of the fish and divided them into 2 categories:

• crepusculars are fish that see well at night, so they try to hunt in the dark and rest during the day, this is due to the anatomical structure of the eyeball. Most predators fall into this category;
• light-loving - have a special eye structure that allows them to see well in daylight. Based on this, fish rest at night and are actively awake during the day.

You should not allow crepuscular and light-loving fish together in the same aquarium because:

• their characters are incompatible, predators will begin to feed on decorative, kind fish;
• twilight fish are uncomfortable being in the company of fish that love a lot of lighting.

Winter and summer hibernation

Some fish are able to hibernate in winter. Naturally, this is a little different from what we are used to understanding, and is expressed by inaction, decreased physical functions, and decreased metabolism. Also during this period, you can see how aquarium pets froze in the water column or lay down on the bottom.

Summer hibernation is very important for fish. Thanks to it, they are able to easily tolerate heat and survive in high temperatures or drought.

African residents have discovered an amazing fish that can form a “mud cocoon” and hide in it for several months. Aquarium pets rarely use this function, but when they find themselves in an uncomfortable environment, they easily adapt to it using “summer hibernation.”

Do fish sleep the same?

There are several types of fish: bony and cartilaginous. The bulk of aquarium inhabitants are bony, they are able to hang in the water and hibernate. This is due to the presence of a swim bladder, which is filled with air. Therefore, the more oxygen it contains, the higher the fish can hang.

Cartilaginous fish are rarely found in aquariums, but they do exist, these are loaches and ancistrus. They do not have a swim bladder, so they sleep on the bottom, like sharks or stingrays.

There are also fish that sleep quite unusually, take, for example, the parrot fish. These creatures love to sleep “under the covers”; for this they release mucus through the oral cavity and become enveloped in it. This protects them and protects them from stressful situations, and when they wake up, the fish leaves its secluded “blanket”. Besides these aquatic inhabitants, there are others who sleep in equally unusual ways, for example, hiding in a cave or an established castle.

Why do you need to know the sleep patterns of fish?

People need to know this information for various reasons: just interesting, to tell their children, or to create a comfortable environment for their pets. Pisces, like people, cannot live without sleep, this can affect their health and cause insomnia and illness.

To protect them, do the following:

• it is necessary to turn off the lights in the room at night;
• before buying fish, you need to study their anatomical features, sleep patterns, what conditions they like, and purchase pets with approximately the same interests, including rest time;
• If an aquarist keeps fish that sleep during the day, it is worth planting it with thick algae, because there they can hide and rest.

Despite the anatomical features of fish, they also sleep, but their sleep is different from human sleep. Fish cannot dream and reduce brain activity, but only reduce physical activity for a short period of time, but if an aquarium inhabitant finds himself in an uncomfortable situation, then he hibernates for an indefinite period.

Watch how a goldfish sleeps:

We recently got a small aquarium at home. Friends gave it for our wedding anniversary. This is probably more of a gift for our cat, he constantly sits and watches the fish. Surprisingly, they are almost constantly on the move. The question arises whether they sleep at all. Now I will answer it for you.

Do fish sleep?

The first thing that tells us about the state of sleep is closed eyes. In the case of fish, we will never see them with closed eyes. The fact is that they just don't have eyelids. The eye of all animals and people has an eyelid in order to perform a protective function and prevent the mucous membrane from drying out. The fish, of course, are not in danger.

The absence of eyelids does not mean that fish never sleep. They just sleep differently than we do. Due to the characteristics of their habitat and the structure of their body fish do not fall into deep and motionless sleep. This creates the false impression that the fish are constantly moving and never fall asleep.

How does sleep differ in fish?

It is better to call the state of sleep in fish period of slow activity. At this time of the fish everyone around hears and at any second they can return to the active phase of life. Unlike other animals, during sleep the brain of fish continues to function as before, that is, they are always in a conscious state.

If you watch the fish for a long time, you can still notice the moment when they freeze for a short period of time. We can say that it is at this time that the fish goes into sleep.

What affects the sleep time of fish

Not all fish sleep at the same time. The sleep period is affected by the following: factors:

• habitat;
• environmental conditions;
• way of eating.

That is why fish are divided into day and night fish. The difference between them is that diurnal fish have eyes built in such a way that they see better in the water during daylight hours. On the contrary, nocturnal fish have eyes that are too sensitive to daylight, so they prefer to rest at this time. By the way, most of the predatory fish are awake at night. In the dark water column they are able to better see their prey.

Proroy fishermen and aquarium owners ask the question: do fish sleep? The question arises for good reason, because no one has seen fish with their eyes closed. They just have nothing to cover - fish have no eyelids. They rest differently than is customary for humans, birds and mammals.

Pisces Dream- This is a rest phase, during which all functions slow down, the body becomes motionless, and reactions are weakened. Some fish at depth do not react to external stimuli (you can touch them or shine a flashlight in their eyes). Others feel the slightest danger. Many fish become almost motionless while resting. And some (tuna, sharks) are constantly in motion, lying on the water against the current. If there is no current flowing through their gills, they may suffocate.

Peculiarities of rest of different types of fish

The specifics of fish rest depend on their species. So, astronotuses lie on the bottom or hang upside down. The clown fish is placed on its side at the bottom of the aquarium. Other species simply hover motionless.

How do fish sleep in nature?

Cod - lying down, flounder buries itself in the sand, herring - belly up, drifting in the water flow. Most fish look for secluded corners to sleep - among stones, rock crevices, algae and corals.

Not all fish sleep at night. Nocturnal predators (burbot, catfish) prefer daytime sleep. But after a restless night, a fish with a diurnal lifestyle can allow itself a “quiet hour” during the day. Dolphins surpassed everyone (though these are not fish, but mammals). They hardly sleep. During rest, the hemispheres of their brains are awake alternately so that they can float to the surface and inhale air. The rest of the time, both hemispheres work. In general, the features of fish recreation depend solely on their species.

Owners of aquarium pets rarely think about how fish sleep. The eyes of underwater inhabitants always remain open, so it seems that they never fall asleep. However, this is not entirely true. Fish, just like most living creatures on the planet, need rest to recuperate, but they do it in a very original way.

The eyes of underwater inhabitants always remain open, so it seems that they never fall asleep.

Day and night sleep of fish

Most creatures living underwater have eyes that are designed differently than their terrestrial counterparts. They do not need eyelids and eyelashes to constantly keep the iris hydrated; their permanent habitat does this perfectly. That is why fish sleep, just like they are awake - with their eyes open.

The state when all processes occurring in the body are suspended is usually called sleep. During this period, not only the heart rate slows down, but also brain activity decreases significantly. For most fish this occurs at night, but there are also species that prefer to rest during the day. These are usually nocturnal hunters such as catfish or pike.

In order to understand whether aquarium fish sleep at night, just watch them for a few minutes in the dark. Pets are in the arms of Morpheus if:

• remain in one place for several minutes;
• hiding among plants or stones;
• lie on their side motionless at the bottom of the aquarium.

This condition is also typical for sick fish, so you should be wary if it occurs during the day or lasts for a long time.

If the fish remain in one place for several minutes, then most likely they are sleeping.

Wild inhabitants of reservoirs

While it is quite easy to see at night whether fish are sleeping in an aquarium, what their relatives are doing in open water is much more difficult to find out. It turns out that it all depends on the type of waterfowl. Not all of them prefer to rest in the dark, but even those who do choose their own way. For example:

• cod prefers to lie on the bottom with its belly down;
• herring often sleeps with its belly up, hovering in the water;
• flounder likes to bury itself in mud or sand;
• Most sharks doze while moving because they do not have an air bladder.

It is very difficult to understand whether fish sleep well at night or just doze. After all, in case of any danger, they are ready to immediately interrupt their rest. It is believed that their brain is always in a state of wakefulness Therefore, the reaction to external stimuli in fish is almost instantaneous. It’s easy to check - you just need to turn on a bright light at night and watch the pets in the aquarium.

Features of keeping an aquarium

Before buying an aquarium and having swimming pets, you should carefully study all the nuances of their maintenance. Irresponsible owners rarely think that fish are living beings with their own needs. A comfortable living environment is the first thing an owner should provide for their pets, even if they are just silent creatures in the water. There are three main rules that must be strictly followed when keeping aquarium fish:

• purity;
• correct selection of feed;
• daily rest for pets.

Many owners simply ignore the last point, leaving the lighting on all night, and this can greatly damage the health of the inhabitants of the aquarium. It does not matter whether the fish sleeps at night or prefers to rest during the day, conditions close to their natural habitat must be strictly observed.

Conditions close to the natural habitat must be strictly observed when keeping aquarium fish.

Cleaning an artificial reservoir and timely replacement of water also play an important role in keeping fish. Lack of oxygen can lead to illness in pets and, as a result, to their death.

Excess feed can be just as dangerous as not enough feed. Overeating, the fish become lethargic, move little and sleep a lot. This can disrupt their natural digestion process and kill the pets.

In addition to clean water and proper feeding, The design of the aquarium plays an important role. Fish need plants and barriers to be able to rest during the day, as well as properly selected devices to maintain oxygen levels and illuminate an artificial reservoir.

Selection of fish

You can’t just buy an aquarium and put different inhabitants in it. Even ornamental fish have predatory species, and if they are placed together with ordinary fish, it is not difficult to guess how it all might end. To avoid this, you should:

• carefully study the selected type;
• populate the pond with pets of approximately the same age;
• buy different types with the same rhythm of life;
• keep fish that have similar food preferences.

If you follow these simple rules, your aquarium fish will feel more comfortable. After all, if all pets eat and sleep at the same time, this will not only add activity to them, but will also prolong their existence.

Owners of artificial ponds, as a rule, love to watch their pets through glass as they gracefully swim among green vegetation and decorations. And sooner or later, the question of how fish sleep in an aquarium begins to worry aquarists, especially beginners. Of course, fish, like all living creatures on the planet, need sleep, but they experience it in a special way.

The concept of sleep is interpreted as the physical state of the body when its reactions to the environment are reduced and brain activity is almost minimal. This is how all people sleep, but fish sleep differently because their biological functions are not the same as other creatures.

Features of fish sleep:

• the environment and the specifics of the body structure do not allow fish to completely disconnect from reality;
• fish do not close their eyes due to the lack of eyelids;
• they do not fall into an unconscious state, therefore they partially perceive the actions of others and temperature changes;
• Brain activity remains the same as before sleep.

All these factors mean that the fish do not fall into deep sleep, but seem to be dozing. The sleep time of a particular individual depends on its species. Fish that are energetic during daylight hours sleep at night, and vice versa. For example, catfish are nocturnal inhabitants, and during the day they try to hide in places with dim light, and with the onset of darkness they go out in search of food.

Interesting fact: despite the fact that the dolphin is a mammal, like fish, it lives in water and never sleeps. The hemispheres of his brain go to sleep one by one, for 6 hours each. This feature allows dolphins to escape from insidious predators.

How to recognize a sleeping fish

Everyone knows that fish never close their eyes. The fact is that these living creatures do not have eyelids, but this does not bother the inhabitants of the aquarium at all: at night the reservoir is dark, and specimens sleeping during the day simply swim away to shady places so that the light does not irritate the eyes.

To understand whether fish are sleeping, aquarists evaluate their behavior. Depending on the type and characteristics, all inhabitants of the reservoir sleep differently:

• “hang” in the water or near the bottom;
• lie sideways on the ground;
• float with the current on the surface or cling to plants;
• lie down on the substrate with their belly.

Postures depend on the species of inhabitants. Representatives of the bony species have a swim bladder filled with air. Thanks to it, aquarium fish sleep as if hanging in the air. Cartilaginous specimens fall asleep at the bottom, sometimes lying sideways on the ground. Vivid examples are catfish or bots. But it is capable of secreting mucus from its body, creating a protective cover around itself, where it calmly falls asleep.

Interesting fact: some subspecies of sharks keep their eyes closed while sleeping and their mouths constantly open to avoid water accumulation.

Hibernation in fish

Some aquarium fish are characterized by hibernation - a special sleep cycle during which metabolism decreases and physiological functions slow down. This state differs from normal sleep because it lasts a couple of months. As a rule, inhabitants of reservoirs hibernate in winter, but there are also special species that fall asleep on the eve of summer. For example, the African protoptera fish, saving itself from dehydration, creates a cocoon out of mud, in which it safely waits out the heat until the weather returns to normal.

Another part of the underwater inhabitants falls asleep during the cold season, trying to hide in shady thickets of plants and shelters. However, it is worth noting that fish in an aquarium rarely hibernate.

Why is it so important to know about fish sleep?

Knowledge about the signs of fish sleep is very significant for pond owners. First of all, only with complete information about the preferences of his pet can an aquarist create favorable circumstances for the development and life of the fish. Secondly, fish, no matter how surprising it may sound, are capable of suffering from insomnia, which in the future will lead to the appearance of diseases. To avoid this kind of complications, the following rules must be followed:

• at night, the lighting in the room where the artificial pond is located is turned off;
• the fish tank is equipped with equipment;
• plants and algae are planted in the aquarium, which will serve as a relaxation area;
• the reservoir is filled with shelters and grottoes;
• when selecting and stocking fish, their characteristics are taken into account, for example, night hunters cannot be placed together with daytime individuals;
• At night, the lamps in the aquarium are turned off.

Having information about the sleep of fish, you can create favorable conditions for their existence, thereby extending the life of your pets. And, although the sleep of underwater inhabitants is significantly different from that of humans, they, like any other living beings, need rest and care.