The so-called "fishbone", known as intermuscular bone in biology, is a small bone distributed in the muscle septa on both sides of fish vertebrae, which mainly grows in lower eubony fish. We are familiar with carp, grass carp and salmon, all of which belong to the CYPRINIDAE in the lower true bone fish. Paleontologists found that with the gradual evolution of fish, intermuscular bone experienced a process from less to more, from more to less, and finally disappeared. For example, in the early order, the intermuscular bone is the most, but in the late order, the intermuscular bone still exists, but the number is less than that in the order. In the late order (such as abalone), the intermuscular bone in the body is close to zero. It can be said that the number of fish bones partly reflects the evolutionary history of fish.