Don t the fish in the river breathe? How can they live without breathing?

is to breathe ...

Fish mainly rely on the movement of the mouth and gill cover to complete their breathing action in the water. Bony fishes have two pairs of respiratory valves, one is an oral flap attached to the inner edge of the upper and lower jaws, which prevents the retrograde flow of water from the mouth when the mouth is closed, and the other pair is attached to the posterior edge of the operculum, that is, the gill membrane, which prevents water from pouring back into the gill cavity from the gill foramen, and also plays an important role in the pressure change in the oropharyngeal cavity and gill cavity.

The respiratory movement of fish is a continuous process, mainly using the contraction of the mandibular gill muscles and the coordinated action of the oral cavity to make the oral wall, gill cover and gill membrane move, change the pressure inside the oropharyngeal cavity and gill cavity, causing water to flow in from the mouth and out from the gill hole, and carry out gas exchange while continuously passing through the gill hole. It is thought that the process of fish entering water from their mouths begins with the moment when the gill membranes are tightly closed. The mouth of the fish is opened, the gill bones are sinking, the volume of the oropharyngeal cavity is expanded, the water is sucked into the mouth, and then the mouth of the fish is closed, and the operculum is lifted up, but at this time the gill membrane is still close to the body surface and covers the gill hole, so the space of the gill cavity is increased accordingly, and the internal pressure is reduced, so the water flows from the oropharyngeal cavity into the gill cavity on both sides and through the gill area.

When the water flows through the gill area into the gill cavity, the oral flap has been closed, and the oropharyngeal cavity gradually shrinks under the pressure of muscle contraction, and extends backward to the gill cover, causing the gill cover to be pulled down forcefully, so that the pressure in the gill cavity increases, and the water flowing into and accumulating in the gill cavity will wash away the gill membrane that is close to the body surface and flow out of the body from the gill hole.

Common-sense problem Fish breathe on their gills The water of the river is not distilled water It contains oxygen.

Fish also breathe, but instead of breathing through their mouths, they breathe with their gills.

They breathe! How do you know they don't breathe! Maybe you didn't see it! Maybe it's going to die! Don't breathe!

It is said that they breathe in the water with their gills, and there is oxygen in the water.

Fish market breathes, because oxygen can be dissolved in water, so they can breathe in water, get it? Hope.

The respiratory organ of the fish is the gills. Due to the special structure of evolution, it is necessary to survive in water for a long time. Fish also need oxygen to survive.

It breathes with its gills. Because the body structure of the fish is very special, it can use the gills to absorb oxygen from the water, so that the fish can survive.

For gill respiration. Because the body structure of the fish is adapted to life in the water, it is able to breathe in the water, and the body of the fish is also able to reduce the resistance in the water.

It's possible.

The solubility of oxygen in water is very small, and at 20 a standard atmospheric pressure, a liter of water can only dissolve about 9 milligrams of oxygen, which is about 1 35 of the oxygen content in the air.

The change in the amount of dissolved oxygen in water is closely related to temperature, at standard atmospheric pressure, 0 water can dissolve milligrams of oxygen, and at 35, only milligrams of oxygen can be dissolved. When the temperature of the water environment rises, the solubility of oxygen in the water will drop rapidly, and the amount of dissolved oxygen in the water may not be enough for the fish to breathe normally.

The choking point of most fish is 1 mg l, especially those with a strong metabolism, whose oxygen consumption itself is very large, and once the water temperature is slightly warmer, it may pose a choking risk. This is the reason why in the summer, we often see some fish swimming to the surface of the water and poking their heads out, constantly opening and closing their mouths, which is actually the fish to breathe more oxygen.

The principle of fish respiration

The gills are located in the pharynx of the fish, and the pharyngeal cavity is immediately behind the mouth, which is the anterior part of the digestive tract. The gills are supported by cartilaginous or bony structures, known as gill arches, each with two rows of thin, fleshy protrusions, known as gill filaments. There are abundant capillaries in the gill filaments, and oxygen-rich blood gives the gill filaments a bright red color.

Most fish use gills for breathing, when a fish breathes, it will regularly inhale water from its mouth and force water to flow out through its gills, at which time the gill filaments will absorb oxygen by contacting the water flow, and the flow of water can also ensure that the gills and gills will not be stuck with each other and make the fish lose the ability to breathe.

Fish are lifelong respirators with gills (gills have distinctive characteristics: large gas exchange area; Thin walls, which shortens the distance for oxygen to enter the blood; There is an abundant capillary distribution in the gills; There is a countercurrent exchange mechanism in the gills; The incoming gill blood is hypoxic blood, and the outgoing gill blood is polyoxygen). In addition to gill respiration, some species also have auxiliary respiratory organs (such as some types of ** respiration, intestinal respiration, oropharyngeal cavity epidermal respiration, fold gill respiration, and bladder respiration, etc.).

As far as the whole fish is concerned, the main role of the swim bladder is not to breathe, but to regulate the gas volume in the way of the swim bladder to control the sinking and floating of the fish body in the water. This means that the gills are like our human lungs, except that the gills filter oxygen from the water, while we humans get it directly from the air.

Fish breathe in the water by their gills, which actually filter the water by the gills and absorb the oxygen from the water.

Why are you walking on land.

Fish, like us humans, inhale oxygen, exhale carbon dioxide, and cannot survive without oxygen. Humans breathe with their lungs, while fish breathe with gills.

Fish live in the water, and we see them swimming leisurely in the water, opening their mouths to take a few sips of water from time to time, and not running to the surface to breathe the air, so how do they absorb oxygen? It turns out that there are many dense capillaries in the gills of the fish, and the fish is not drinking water when it opens its mouth wide in the water, but breathing. It turns out that not only is there oxygen in the air, but also oxygen is dissolved in the water.

The water does not enter the stomach after entering the mouth of the fish, but flows out through the gills. When water flows through the gills, the oxygen in the water enters the capillaries and flows down the blood vessels to all parts of the body. Carbon dioxide in the body is also excreted from the body along the blood vessels. This is how fish survive by breathing incessantly in the water with their gills.

The gills of a fish can only absorb oxygen dissolved in the water and cannot breathe oxygen directly in the air. As a result, most fish suffocate due to lack of oxygen when they leave the water. Of course, there are also fish with "special functions", in addition to gills, they also have organs that can breathe air directly, and they later evolved into amphibians.

Because the gills are closed, the water that enters the mouth can be expelled from the body, leaving oxygen for gas exchange in the body, so the fish can breathe in the water.

Fish breathe with gills.

In fact, fish, like people, must breathe oxygen to survive, there is oxygen in the air and water, and the human lungs can separate the oxygen in the air but cannot absorb the oxygen in the water, so people can only live on land.

And can't breathe in the water, most fish don't have lungs.

But there are gills that separate oxygen from the water.

So, the fish can breathe oxygen in the water.

There are also some fish, in addition to gills and lungs.

So those fish can live on land for a while.

Some of them can only live for a few hours, while others can live for a few days.

Others can even live on land for a few years.

When the fish is in the water, each gill plate, gill filament, and gill segment are fully opened, so that the contact area between the gills and the water is expanded, increasing the chance of ingestion of dissolved oxygen in the water. There are microvessels in the gill patches, where the epidermis is very thin, and when the blood flows through it, the gas exchange is completed: the carbon dioxide brought by passes through the thin walls of the gill patches and is sent to the water; At the same time, it absorbs oxygen from the water, and the oxygen is transported to all parts of the body with the blood circulation.

Due to the alternating opening and closing of the mouth and gill cover, water can continuously enter the oral cavity from the mouth, through the pharynx to the gill cavity, contact with the gill filament, and then discharge from the gill hole to the outside.

Fish have gills and breathe with gills in the water; Fish have fins, and they float up and down by the swing of the fins.

Because fish have gills, they can help him breathe in the water.

Because fish have gills, right, right, absolutely right.

Fish can breathe in water because they have gills, a special organ that allows the dense capillaries in the gill filaments to exchange gases with the water to obtain oxygen when the water passes through. Once out of the water, the gill filaments stick together, causing it to be unable to take in oxygen, and it dies. However, some fish have auxiliary respiratory organs and can survive out of water.

Fish have the characteristics of being suitable for living in water: the color of the body of the fish is the protective color of the fish. The body is streamlined, large in the middle and small at the end.

The surface of the body is covered with scales, which protect the body; There is a layer of mucus on the surface of the scales, which reduces the resistance of the water when swimming. There is a lateral line on both sides of the body, which is connected to the nerve, which is mainly used to determine the direction and sense the flow of water. The body of a fish has pectoral fins, dorsal fins, pelvic fins, and caudal fins, which are the locomotor organs of the fish in the water.

Fish breathe with gills. There is a swim bladder in the body, the main role is to regulate the specific gravity of the body, the swim bladder in the coordination of the fins, can make the fish stay in different water layers.

Fish belong to the lower animals of vertebrates because they cannot live without water all their lives, breathe with gills, heart-atrium-ventricles, a circulatory route, and arterial and venous blood are mixed; In particular, the reproduction of fish is naturally hatched by in vitro fertilization, and the body temperature is not constant.

The role of the fin: The dorsal and anal fins mainly play a stabilizing and balancing role when moving. The tail fin works with the muscles on the side of the body to propel the fish and control the direction.

The main function of pectoral and pelvic fins is to maintain the balance of the fish, cooperate with the body of the fish, and adjust the lifting of the fish. However, pectoral fins are more versatile than pelvic fins, and they can be used like oars to move the fish forward slowly.

Because the gills of a fish are only adapted to absorb oxygen from the water and not to the air, it can't.

Because fish have gills, they can breathe in the water.

Because the gills can absorb oxygen from the water.

When there is a lack of oxygen in the water, the fish will go to the surface to breathe, and there are generally two situations.

One is the weather, the air pressure before the rain is reduced, the oxygen content in the water is insufficient, the fish will float to the surface, this situation does not need to worry too much, you can use an aerator (fish pond) or an aerator (fish tank) to increase oxygen, because the fish will not come to the surface of the water unless it is uncomfortable.

The second is that the breeding density is too large, or the deterioration of water quality is caused, when the production of fertilizer and feeding too much may cause water eutrophication, resulting in water quality decline, lack of oxygen in the water, there are also old mud ponds under low pressure Chen Tang flooding caused by lack of oxygen in the water, then it is more dangerous, must be changed immediately, otherwise the pond fish will die in large numbers.

Fish are able to metabolize through respiration in the water, mainly because it has a vital organ - the gills. Gill are structures that are specially adapted to breathe in water. The throat of the fish has 4 gills on each side, and each gill is composed of gill pieces and gill filaments.

When breathing, the gill and gill filaments open completely, increasing the contact area of the gills with the water, increasing the chance of binding to dissolved oxygen in the water.

Fish breathe in the water with their mouths open and closed; When it opens its mouth, it sucks in water and closes the operculum, and when it closes, it opens to allow water to flow out. In the process of water flowing through the gills, the dissolved oxygen in the water is absorbed by the microvessels on the gills, and at the same time the carbon dioxide is discharged into the water.

Dolphins can rent oranges to swim while sleeping. It has two cerebral hemispheres, and every ten minutes, the two cerebral hemispheres work alternately, one asleep and one awake. I have plenty of time to sleep, and I constantly change my swimming position.

Although they continue to swim in the cheating group, the left and right sides of the brain take turns resting.

There is also a special type of fish, the barramundi. It is a freshwater fish similar to coelacanths. In ancient times, it was bred in large numbers on the earth, and there are still a few of its species that have been preserved, which can be said to be a kind of "living fossil".

The jaw is self-grafting, usually breathes with gills, and can be used as a lung to breathe when it dries up, the swim bladder has an opening in the esophagus, which can be called the inner nostrils, the dorsal fin, anal fin and caudal fin are healed together, there is no hard bone on the jaw, and there are special tooth plates. For example, the larramundi has two lungs that meet the glottis and esophagus, the gills and gills are more degenerate, and the heart has two ventricles, one of which receives blood from the lungs, and the arterial cone has valves that separate the blood from the gill from the gill area. Not long ago, some scholars suggested that lungfish are also closest to living amphibians in terms of epiglottis cartilage, pituitary structure and genamine components, lens protein, bile salts, and gill arch muscles.