Have you ever wondered: Why do fish have scales? Do those slippery scales help the fish?
The body of the fish is very soft, the scales are part of the skin. Without scales, water will constantly seep into the fish’s body, the water from the fish’s body will also escape, they will not be able to live.
When a fish is stripped of its scales, it is like a fish stripped of its skin, the fish will die.
Scales are derivatives of fish skin, which has the function of protecting the body of fish, but there are some species that do not have scales on their bodies because their scales have been degraded. For example, an eel, the whole body of the eel is covered with a very sticky slime. Endocrine glands in their skin secrete large amounts of mucus. This mucus layer is not resistant to the impact of hard objects, but can prevent the invasion of toxic bacteria. Also because the slime is very slippery, it is difficult to catch them. The scales on the eel’s body are degraded into a thin layer of skin, with many small blood vessels to support respiration.
Why do dead fish often lie on their backs?
Although the fish bladder is an important part of the fish’s ability to float or sink or float in the water without much energy, this organ is what causes the fish to not be able to “stand” but often tilt slightly and have can flip upside down at any time.
The reason is because the fish bladder is almost entirely at the center of the body but slightly downwards, close to the stomach.
That makes the fish always in a slightly tilted position and ready to “swim back”. Because of this, we often see fish flapping their fins even when not moving or balancing in the water.
When fish are sick or injured, they may also swim on their sides or back because they lose their ability to maintain balance in the water and tend to want to float to the surface.
When the fish die, they completely lose their balance and the amount of air left in the fish’s bladder causes them to float to the surface.
At the same time, most of the fish’s parts including bones and muscles are usually concentrated in the back, so when floating, the fish often flips over due to the weight of these parts.
However, a dead fish does not have to float on its back. In the event that a fish dies when there is no air left in the bubble, of course the fish will sink and decompose as usual.