The difference between the male and female turtles is that the female turtle has a rounder body, and the male turtle has a longer body. The flat bottom is the female turtle, and the concave bottom is the male turtle. The one with the short tail is the female turtle, and the one with the long tail is the male turtle. There is also a difference in meat quality.

The fish species, whose scientific name is Taoyu, is also known as rice fish, sensitive fish, and sensitive fish. It is a rare and valuable edible fish. In the Chaoshan area, it is customary to call the isinglass of the mullet fish "turtle fish". "Soil" is called local. When the anchovy swim bladder is taken out of the fish body, the surface usually has a lot of blood tendons and a thick layer of fat. It is much more difficult to clean than other swim bladders. Local fishermen have to use spoons and other tools to slowly peel off the fat layer on the surface. Despite this, it is inevitable that there will be grease in the glue, especially at the head of the glue. Moreover, many dolphin swim bladders are usually already congested with blood in the body of the fish when they are caught and landed. Even if they are soaked in ice water immediately after being taken out, the blood color will only become lighter and cannot be completely removed. Also known as "blood fish". It is rich in collagen, contains a variety of minerals and vitamins, and is a high-protein, low-fat healthy aquatic food. It can enhance gastrointestinal digestion and absorption function, strengthen brain and nerve function, prevent mental retardation, slow reaction, forgetfulness in old age, regulate immune function, etc.