Smell why the fish turned over when they died?

When the fish dies, the body loses control and cannot maintain a state of balance.

The swim bladder is on the abdomen and naturally rolls up.

There is an organ in the body of the fish that regulates the specific gravity of the body called the swim bladder. It can deflate or inhale at different depths to adjust the specific gravity of the body, so that the specific gravity of the surrounding water is the same, so that the fish can stay in the water effortlessly, after the fish dies, it loses its ability to adjust, and the swim bladder is full of gas, and the specific gravity of the body is reduced. The back of the fish is mostly a place with more vertebrae and muscles, and the specific gravity is larger, while the abdomen is mostly internal organs, with a large cavity and a small specific gravity, so after the fish dies, the abdomen with a small specific gravity will face upward.

When the fish are healthy, they use the swim bladder to regulate the density and the nervous system to control the motor system to adjust the posture.

If at this time, the fish is in a semi-comatose state, and the nervous system loses the ability to control the locomotor system; Or the muscles have been paralyzed, at this time, the swim bladder of the fish is filled with more air, the buoyancy is relatively large, and the swim bladder is located in the abdomen, so it will float, and the abdomen is facing upward.

The same is true when the fish die.

But some fish, such as the snakehead, are so dense and resistant to hypoxia that even after they die, they sink underwater.

In fact, this is just a kind of neural reflex activity that vertebrates haveFor example, if we humans are gently hit on the knee with a hammer, our legs will also bounce. After the fish dies, only the brain stops moving, but the body is not completely dead for the time being, so the fish will still move after death.

The body does not die for a short period of time after the fish dies, so the muscles will spasm and twitch, but this reaction is not controlled by the brain. We know that vertebrates have nerve reflex arcs, and the nerves in the vertebrate body are divided into central nerves and migratory nerves, of which the migratory nerves are lower nerves, which are controlled by the spinal cord, that is, they play a role in nerve reflexes.

Behavior after the death of the fish

1. Loss of balance.

Fish live in water, so to maintain balance at all times, it is not only the fins that depend on the fins, but also the swim bladders to regulate. When the fish dies, the swim bladder's regulatory function fails, and as a result, the original abdominal density decreases, causing it to float on the surface of the water with its belly facing up.

2. Stiff body.

Fish become stiff for a period of time after death, usually for a few minutes or hours. The reason why the time is not necessarily depends on the type, nutritional status and storage method. In addition, the stiffness of the fish is also a sign of freshness.

3. Autolysis corruption.

As mentioned above, the stiffness of the fish will last for a while, after which it will move on to the next stage, and its muscles and internal organs will begin to dissolve, which also means that it will decay. Microorganisms slowly break it down, and in the process, its color and smell change significantly.