? Scales are a structure of fish. Many fish have scales, but some fish do not have scales. According to the presence or absence of scales and the size of scales, all fish can be preliminarily divided into scaly fish and scaleless fish. Loach is one of the common fish, which is distributed in many parts of our country. Loach is scaly. Their scales are round in shape and relatively numerous. But their scales are only on the body, and there are no scales on the head.
Some people believe that loaches have no scales because their scales are very difficult to observe. In terms of area, the scales of loach are relatively small and not obvious. From the position, their scales are buried under their skin, which is not easy to observe. Moreover, there is a lot of mucus on the surface of loach's body, which makes their body feel smooth, and it is not easy to find their scales when touching. Although the scales of loach are not obvious, they play an important role in isolating some harmful bacteria and other substances from the body of loach and protecting their health.
? As mentioned above, loach is a kind of fish with scales. However, in terms of classification, they belong to scaleless fish. This is because the concept of scaleless fish does not only refer to fish without scales. Fish without scales are typical scaleless fish, but in addition, there is a kind of fish with smaller scales, which also belongs to scaleless fish. Loach belongs to this situation. Their scales are smaller and not easy to observe, which belongs to the category of scaleless fish. According to the specific classification, it belongs to freshwater scaleless fish.
