Do fish need to sleep at night? Where do fish sleep at night?

Unlike humans, fish don't have eyelids and can't close their eyes when sleeping, so they sleep with their eyes open, so it's not easy to master their posture when sleeping.

Migratory fish, on the other hand, swim and sleep at the same time. They swim all the time because they have to constantly spit out water to keep breathing, such as sharks, tuna, mackerel and chia, swimming back and forth day and night, making it difficult to figure out when they are sleeping; When is awake.

Some fish, such as split-billfish and South Sea parrotfish, will secrete a special gelatinous substance in its body, and when they want to sleep, they blow a big bubble like a child, and the gelatinous bubble hardens when exposed to water, and then they get into the bubble, leaving only a small hole in the mouth, just like in a sleeping bag.

Fish sleep with their eyes open.

Fish are vertebrates, need to sleep to eliminate the fatigue of the nervous system and limbs, but the fish has no eyelids, it can't close its eyes when sleeping, it sometimes sleeps in the dark, sometimes it sleeps in the sand or secreted bubbles to sleep, sometimes it swims while sleeping, all kinds of different postures, just live freely.

Fish do not sleep with their eyes closed like humans or other animals because they do not have a layer of eyelid-like eyelids outside their eyes, and they do not close their eyes at all. So when you see a fish with its big eyes open and still quietly, it's probably sleeping.

Many fish have a balloon-like swim bladder in their stomachs, and adjusting the amount of air in the swim bladder can increase or decrease buoyancy. When the swim bladder expands, it floats, and when it gets smaller, it sinks. Most fish have a series of small holes on both sides of the body, which is the lateral line, which can make the fish feel the flow or vibration of the water.

I think the fish at night. They all slept in the water, in the fish tank. in the reservoir. The water level suitable for parenting growth.

When there is no light at night, the fish will find a place that is less affected by the outside world to stay (such as in the aquatic grass), breathe slowly, the body color becomes lighter, the demeanor is dull, the front fin rarely moves just to maintain the balance of the body, and does not take the initiative to swim, if the light is not turned on suddenly to give the light time to turn on, the state of the fish will not only not recover immediately, but even frightened. It will take some time before you slowly start swimming and foraging. If the lights are turned off in advance, they will remain active for a while.

And if they don't turn on the lights when they are used to it, they will still enter the active state when the lights are turned on. This is what I have seen over the years with my observations of domestic ornamental fish. So I think that fish not only sleep, but also have a fixed schedule.

In the hull bushes or in the seaweed.

Of course, the fish sleep in the water, and if they sleep in the bowl, they will spoil.

Sleep in the water, or you will be boiled in the pot...

Normally, fish sleep at night, but there are some that are nocturnal and sleep during the day and come out at night.

In order to ensure that the fish can sleep peacefully, it is best to turn off the lights while sleeping and avoid disturbing them with noise, which may cause them to be frightened. In addition, it is best to place some aquatic plants or shelters in the fish tank, so that the fish can have a place to hide.

We have the impression that one of the most basic actions of sleeping is to close your eyes, but fish always have their eyes open, so many people think that fish will never sleep in their lives. But in fact, you don't have to close your eyes to sleep, especially for fish, they can't even close their eyes. This is because if you want to close your eyes, your eyelids have to fall naturally, but fish don't have eyelids, so you can only keep your eyes open for the rest of your life.

Although the eyes are open, fish also need to sleep every day, and the study of fish sleep began more than 100 years ago, but at that time, scientists observed the abnormal behavior of fish, such as almost stopping swimming, and not responding to objects passing by.

Yes, in general, when the light is dim to a certain extent, the fish will sleep, and the state is that it floats motionless in the middle and lower part of the water, that is, it has fallen asleep.

1.Fish to sleep:

Fish, like all vertebrates, sleep to relieve fatigue of the central nervous system and limbs, but fish sleep differently. There are about 20,000 species of fish in the world, and there are 2,500 species in China, whether it is marine fish or freshwater fish, except for some cartilaginous fish such as true sharks, which have instantaneous folds equivalent to eyelids, which can cover part or all of the eyes, other bony fish such as carp, crucian carp, hairtail and pomfret have no eyelids. Anchovies, breezy and mullets, such as anchovies, have fat-eyed faces, but transparent fish do not have eyelids, so it is difficult to tell if they are awake or asleep.

2.Sleep habits of fish:

When fish sleep, they will stop swimming and stay in one place, but the length of time they stop swimming varies from fish to fish. However, as long as the fish is really asleep, reach out and grab the fish, just like a land vertebrate that is sleeping. There are also different layers of water in which fish sleep, some are on the bottom, some are in the middle layer, and some are sleeping on the bottom of the water, such as parrotfish.

Silver carp and silver carp like to take a nap under the aquatic plants in the summer afternoon.

Yes, because the fish has a layer of eyelids on its eyes, it is impossible to close its eyes when sleeping, so the fish remains highly alert when sleeping.

Yes, although fish are lower vertebrates, the structure of their eyes is similar to that of the human eye. The difference is that the lens of the human eye is oblate and round, allowing you to see things in the distance; The lens of the fish's eye, on the other hand, is spherical in shape, and only close objects can be seen. All fish are short-sighted, and they rarely see objects up to 12 meters away, which is related to the fact that the curvature of their lenses cannot be changed.

Although fish have a visual system, their eyesight is not very good even in the daytime, and the range they can see is only a few meters, so they are even more invisible at night, but their sense of smell is much more acute than that of other creatures, so they generally rely on their sense of smell when they are active at night, and their eyes are completely useless.