Isinglass place of Russian isinglass. The bladders, once removed from the fish, processed, and dried, are formed into various shapes for use. Before the inexpensive production of gelatin and other competing products, isinglass was used in confectionery and desserts such as fruit jelly and "blancmange". Isinglass finings are widely used as a processing aid in the British brewing industry to accelerate the fining, or clarification, of beer. It is used particularly in the production of cask-conditioned beers, although a few cask ales are available which are not fined using isinglass. The finings flocculate the live yeast in the beer into a
Swim bladder and a swim bladder. The cartilaginous fish (e.g., sharks and rays) split from the other fishes about 420 million years ago, and lack both lungs and swim bladders, suggesting that these structures evolved after that split. Correspondingly, these fish also have both heterocercal and stiff, wing-like pectoral fins which provide the necessary lift needed due to the lack of swim bladders. Teleost fish with swim bladders have neutral buoyancy, and have no need for this lift. Sonar operators, using the newly developed sonar technology during World War II, were puzzled by what appeared to be a false sea floor 300–500