For the question of fish grow fish scales, some people will be curious. Why do fish grow fish scales? Then what is the function of fish scales?

So fish scales are skin derivatives on the body surface of most fish, and are transparent, slightly fishy-smelling flakes. The body surface of most fish is clothed in solid scales, which are derivatives of the skin and are usually arranged in an imbricate pattern. Some fish) have degenerated scales, and there are also fish with a few scales remaining. The body surface of fish, whether scaled or not, secretes a large amount of mucus, which undoubtedly serves to lubricate and protect the body.

I , lateral line scales

Fish body on both sides of the majority of one or more from a separate small nest evolved into a tube-like line, called lateral line scales , each piece of lateral line scales have lateral line holes, can feel the low-frequency vibration of the water. The scales of bony fish are usually identified according to their number, size, and arrangement, and the arrangement of the number of scales is often expressed as a fractional formula called scale formula: for example, the scale formula of crucian carp is 28-30, which means that crucian carp has 28 to 30 lateral line scales, 5 to 6 lateral line scales, and 5 to 7 lower lateral line scales. The lateral line is a unique sensory organ of fish.

It is a tubular system of structures deep under the skin- and is closely connected to the nervous system. There are many small tubules that pass through the scales to communicate with the outside world. These small pores are arranged in lines on the lateral surface of the body. In common freshwater fishes, there is only one lateral line, which runs from the back of the head roughly along the midline of the body to the base of the caudal fin. However, the lateral line of Nilotic carp is interrupted and divided into upper and lower segments. The lateral line has auditory and tactile functions, and can feel the vibration wave of water, the direction of water flow and the change of water pressure.

Two, the role of fish scales on the fish:

①In the fish belly scales, can reflect and refract bright light, as if a mirror, thus making the bottom of the ferocious aquatic animals dazzle, produce the water of heaven and earth, do not distinguish objects, become a natural camouflage.

②As a layer of external skeleton, the scales can both make the fish body to maintain a certain appearance, but also reduce the friction with the water. In addition, biologists know the age of the fish according to the annual rings on the scales (each ring indicates a winter); they can also more correctly grasp its growth, mortality and health.

③Provides a protective barrier for the fish, isolating it from the countless microorganisms around it, effectively avoiding infection and resisting disease.

So for the fish scales he will secrete some mucus, which has the effect of protecting the fish body.