What are the characteristics of mussels?

In calm water, mussels often slightly open their shells and stick out their white feet. Its feet are very special and shaped like axes, so it is called axe feet, and mussels move slowly under water by it. When disturbed, the mussel immediately withdraws its feet, and the two shells are tightly closed like two doors to protect its soft body.

The back of the two shells are connected by a "ligament", which can make the two shells open. There are columnar obturator internus at the front and back ends of the mussel. When mussels are slightly disturbed, the shells will close tightly, which is the result of obturator internus contraction.

When we open the mussel shell, we will see that the mussel shell is between the two shells, and there is a thin and soft protective coat outside the internal organs, called the mantle. The innermost layer of the shell, the most beautiful scenery, is full of luster and shines like a pearl. This is called "nacre", which is composed of nacre secreted by the mantle, and pearls are also composed of nacre.

Pearl is not only a high-grade ornament, but also a precious medicinal material. At present, there are many pearl farms in China, which cultivate shellfish and pearls artificially.