The fish bladder is also known as fish maw, and the bladder is commonly called the fish bubble.Most bony marine fishes living in upper and middle layers of seawater have bladders.The volume of a fish bladder typically accounts for about 5% of its body.Its shape can be oval, conical, heart-shaped, or horseshoe-shaped.The gases primarily filling the bladder are oxygen, ammonia, and carbon dioxide, with oxygen being the most abundant.Therefore, in environments lacking oxygen, the fish bladder can serve as an auxiliary respiratory organ to provide oxygen for the fish.Fresh high-quality fish maw (commonly known as fish bubble) dried products are a traditional seafood delicacy, renowned for its sticky substance, and are also called fish gelatin or flower gelatin.
