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
Elasmobranchii grooved to constitute a clasper for the transmission of sperm. These fish are widely distributed in tropical and temperate waters. Many fish maintain buoyancy with swim bladders. However elasmobranchs lack swim bladders, and maintain buoyancy instead with large livers that are full of oil. This stored oil may also function as a nutrient when food is scarce. Deep sea sharks are usually targeted for their oil, because the livers of these species can weigh up to 20% of their total weight. Fossilised shark teeth are known from the early Devonian, around 400 million years ago. During the following Carboniferous period,