What is the position of the fish when it sleeps?

Yes, they have to sleep too -- because they don't have eyelids, so we can't tell if a fish is asleep. In fact, fish, like all vertebrates, need to sleep in order to eliminate fatigue, but the sleeping position of the fish is different. Even if you fall asleep, you don't feel like it's sleeping.

So, how do fish sleep? It starts with the structure of the fish's eye. When terrestrial vertebrates sleep, they close their eyelids, block out the light, and sleep with their eyes closed.

However, most fish do not have eyelids, so it is difficult to tell whether they are asleep or awake. Fish stop swimming while sleeping, and stay in one place, but the length of time they stop swimming varies depending on the type of fish. The water layer where the fish sleep is also different, some are in the bottom layer, some are in the middle layer, and some like to hide under the aquatic weeds to sleep, which is really different.

When a person is asleep, his breathing is slow and even, and his breathing is rhythmic. While the fish sleeps, you can see it moving its gill covers, dorsal fins, and anal fins slowly and rhythmically (fanning), while the caudal fin is erect and the pectoral and pelvic fins are flattened to keep the body balanced. Fish don't sleep long and are alert, as if people are taking a nap.

This is also a trait shared by other lower vertebrates.

The fish sleeps there motionless and closes its eyes.

Fish live in the water and naturally sleep in the water as well. Since these animals do not have eyelids, they also sleep with their eyes open. Usually when the fish sleeps, it stays in one place for a long time, and at the same time, every once in a while, the fins shake a little.

In addition, some fish sleep in search of places that are not easy to find, such as aquatic plants or crevices in stones

Features of fish sleeping:

1. Hide in the dark: Fish live in the water and will encounter natural enemies anytime and anywhere, so usually they will hide in the dark when they sleep to avoid being discovered. Most fish prefer to hide near rocks or aquatic plants, and use these things to cover their bodies and keep themselves safe.

2. Get into the sand: There are some demersal fish, their body is flattened, and it is not easy to hide in aquatic plants, but they can bury themselves in the sand, which also has a good hiding effect, which can not only ensure quiet, but also avoid the predators of natural enemies.

3. Secreting bubbles: In addition to finding a place to hide, there is also a way to protect yourself while sleeping, that is, secreting bubbles, such as split-billfish or South Sea parrotfish, this kind of fish can secrete a special gelatinous substance, wrapping itself like a bubble, so as to avoid all kinds of threats.

4. Swimming while sleeping: Some fish in the ocean must swim all the time in order to maintain their body functions, even when sleeping, such as sharks, tuna, etc., will swim while sleeping.

The habits of fish

Fish swim around underwater and breathe by gills for the main purpose of foraging. It is an ectothermic animal, and its body temperature changes with the water temperature, and the water temperature changes in different seasons will affect the range of activities of the fish.

When the weather is hot and the air pressure is low, the fish will be anorexic. When the water temperature becomes low, the metabolic function of the fish will slow down and they will refuse to eat. When the water temperature is right and oxygen is sufficient, the fish will be more active and will actively forage.

Fish are vertebrates and need to sleep to eliminate the fatigue of the nervous system and limbs, but fish have no eyelids, so do netizens know how fish sleep? Let's find out.

1. The fish can't close its eyes when sleeping, sometimes it sleeps in the dark, sometimes it sleeps in the sand or secreted bubbles, and sometimes it swims while sleeping, in a variety of different postures.

2. Fish are not like humans, they have no eyelids and cannot close their eyes when sleeping, so they sleep with their eyes open.

3. Therefore, it is not easy to master their posture when sleeping. Here are a few types of fish that sleep in, so please pay attention to them.

That's all there is to know about how fish sleep.