CATDOLL : CATDOLL: How does the mucus on the surface of fish come about? What is its use?

Mucus plays a very important protective role for fish. When fish are alive, there is a kind of goblet cell on the skin that can secrete mucus, which constantly secretes mucus. The mucus covering the fish's body can reduce the friction of the fish in the water, making it easier for the fish to swim. At the same time, it can protect the fish from being eroded by parasites, mold, bacteria and other small organisms, and can also make the skin have a normal permeability to prevent foreign substances from entering the body at will and affecting the fish's ability to live normally. In addition, mucus has the power to condense and precipitate floating mud in the water, making the water in the living environment clear. For fish that live in often turbid water, it is more or less useful to prolong the life. For fish that live in clear water, when the water becomes turbid after floods or heavy rains, mucus also has the same effect, allowing the fish to breathe smoothly and maintain life.

After a fish dies, there is a layer of mucus on its skin that delays the decomposition of the fish surface by bacteria, so that the fish does not go bad too quickly. However, after a certain period of time, the bacteria use up the nitrogen in the attached mucus, causing the fish to begin to decompose and the fish meat to go bad.