Sharks don’t have swim bladders.

Sharks do not have swim bladders because their fins are structured differently from ordinary fish. Their larvae hatch within the mother's body and are born without breastfeeding, while other fish do not have this function. Sharks do not have a swim bladder, so they cannot float up and down in the water like ordinary fish, but must swim constantly to control their bodies in the water.

The swim bladder is an organ found in most bony fishes. It is filled with oxygen, nitrogen and carbon dioxide. Fish use the contraction and expansion of the swim bladder to adjust the density of the fish's body and control the movement of the fish. Rising and sinking in water. Fish maw can be made by drying the fish maw. Fish maw is a typical high-protein and low-fat food.

Introduction to fish maw

Fish maw is also called fish maw and isinglass. It is rich in high-grade collagen and mucopolysaccharides, vitamins, calcium, zinc, iron, selenium and other nutrients. It is as famous as bird's nest, shark's fin, etc. The swim bladder is preferably clean in texture, free of blood, tendons and blood stasis, translucent, and light yellow in color. The larger the swim bladder of the same type and the thicker the gel body, the better the quality, which can be as high as one per pound.

The drier the fish maw, the better. You can put it under a light to take a photo. If the fish maw is translucent, the quality is better. If the humidity is high, it will look dull and dull when illuminated. Some fish maws may even not be completely dry inside when they are dried in the sun. They are usually transparent around the edges and turbid in the center. Male belly is better than female belly. The male's belly is shaped like a saddle. The middle part of the belly is thicker and the sides are thinner. The body has V-shaped stripes. The texture is firm, thick, dry and light, and golden in color.