Fish scales for fish, is a skin derivative, itself is calcium, and usually covers the whole body, some only cover part. It acts like an exoskeleton and can provide some protection. When they encounter some aggressive fish, even if they are attacked, they are not easily injured, but for larger aquatic animals, the protective significance of fish scales is much smaller.
Fish scales are not only attached to the surface of the fish, their own structure is also very special, and people think that the smooth different, its surface has some concave holes, although it will produce additional pressure resistance, but at the same time will reduce friction resistance, and ultimately can play a drag reduction effect, can let the fish swim faster. Thereby being beneficial to predation or escaping from the pursuit of natural enemies.
The scales on the belly of the fish can reflect and refract bright light, just like a mirror. The fierce aquatic animals living on the bottom of the water will feel dazzled when they see it, and thus cannot accurately find the location of the target. This is also a natural camouflage for the fish, which can avoid some dangers.
For freshwater fish, due to osmotic pressure, water will infiltrate into the fish body, and fish scales can play a certain role in hindering the water from entering too fast and swelling the fish to death. Similarly, fish in the sea, the water in the body will continue to flow out, fish scales can play a role in hindering, for fish is also a kind of protection.
