Why do fish drown after leaving the water?

Because the gills of the fish need to be in a humid environment to work properly, if they are placed in the air, the cells of the gills will die due to excessive water loss, and the fish will suffocate to death.

First of all, I will correct one thing, there is oxygen, not oxygen, that is different, and then, the fish is not like us, it can breathe, it swims in the water, when the water passes through the gills, the gills will filter out the oxygen inside, and when the air is in the air, the air will not flow by itself, and the fish will not get enough oxygen, and it will die.

The gills of the fish are equivalent to the lungs of the human body, but the structure is relatively simple, and it cannot breathe after leaving the water (due to its special structure, it cannot obtain oxygen from the air), as for the reason, it is the result of evolution, the gills are more suitable for breathing in water, but there is a species of Brazilian fish that is amphibious and can breathe in the air.

There are abundant hair wash blood vessels, which is conducive to the exchange of gases. Fish are filtered from the water through their gills to combine oxygen molecules with their blood to achieve respiration! It can only absorb oxygen dissolved in water, and the most obvious role of the gills is gas exchange. Absorbs oxygen and removes toxic carbon dioxide.

The gills are protected by a gill cap. Underneath the gills, there are arches made of cartilage. Inside the arch is a comb-like gills raker that prevents food debris from entering the gills. On the outside of the arch are two rows of soft gills.

Fish gills are also free of waste. Most aquarists are aware of the excretion of ammonia into the water by fish, but only a few recognize that large amounts of ammonia (more than 75% in some fish) are actually excreted by gills and not only by urine and solid waste, as is imagined.

Heck, fish also need oxygen for respiration, not oxygen, and water conservancy also has oxygen.

When the fish leaves the water, they die due to lack of oxygen. Fish can't breathe oxygen directly, they breathe oxygen through the gills this organ, the water flows in from the mouth, flows out of the gill holes, and then constantly exchanges gas through the gills, but after the fish leaves the water, the gills will stick together, reducing the breathing area, and the fish will die of lack of oxygen.

Fish

The fish is an etothermic aquatic vertebrate that swims by virtue of the swing of the tail and torso, as well as the coordination of the fins, for gas exchange through the gills.

Fish are the oldest vertebrates and can survive wherever there is water, including freshwater lakes, freshwater rivers, saltwater seas, and saltwater oceans.

According to the shape of the fish, it can be divided into spindle-shaped, side-flattened, club-shaped, and flat-flat. Among them, the spindle shape is the body type of the vast majority of fish, so it is also called the basic type.

Fish need oxygen from the water to breathe, and capillaries in the gill filaments help with gas exchange. Once out of the water, the fish will suffocate due to lack of oxygen.

Fish mainly breathe through the gills, and the water flows in from the mouth and out of the gill holes, and the gas exchange occurs when the skin passes through the gills. Therefore, the gills have a special structure. Fish generally have 5 pairs of gill arches, the inner edge is a gill raker, and the outer side is 2 gill segments, and the gill is composed of countless gill filaments.

Each gill filament gives birth to many protruding gill patches, which are composed of two cells and have abundant microvessels, which are the site of gas exchange. The adjacent gills are staggered and the water is convected in them, guaranteeing maximum gas exchange between the blood and the water.

When the fish leaves the water, the gill filaments and gill pieces are adhered to each other, the breathing area is greatly reduced, and sufficient oxygen can not be supplemented, and the gill filaments are exposed to the air, and the gill filaments are dried out due to water evaporation, which destroys the structure of the gills and makes them lose their respiratory function and die. Although there are fish **, air sacs, and intestinal tubes that can assist breathing, those are far from enough.

Morphological characteristics

The appendages of fish are fins, which are locomotor organs for swimming and maintaining body balance. The fin is composed of a branched fin basal bone and a fin bar, and the fin bar is divided into two types, one is the angular fin bar, which is not segmented or branched, and occurs from the epidermis and is found in cartilaginous fishes; The other is the scaly fins or bony fins, which are derived from the scaly spike family, with segmented, branched or unbranched, and are found in bony fishes, and the fins are connected by thin fins.

There are two types of bony fin spines, which are formed by the deformation of a kind of fin spine, which is a hard spine that is neither branched nor segmented, and is possessed by higher fish. The soft strip is soft and knotty, and its distal branches (called branched fins) or unbranched (called unbranched fins) are formed by the merger of the left and right halves.

Many people think that fish leave the water because of lack of water and die, but this is actually a misconception. The vast majority of the reason why fish die after leaving the water is due to lack of oxygen, and there are two factors that cause fish to lack oxygen.

One is the gills, when the fish is in the water, the gill filaments are all open when it breathes, so that the area of contact with the water will be larger, and thus absorb more oxygen. However, when the fish leaves the water, the gill filaments of the gill part of the fish will stick together due to lack of water, and there is no way to open normally, which is very unfavorable to the breathing of the fish.

Life is inseparable from water, but fish choose to evolve in water.