Isinglass advantageous in situations where minimal use of water is desired for the parchment as the isinglass can be reactivated with an ethanol-water mixture. It also has a greater adhesive strength than many other adhesives used for parchment repair. Isinglass Isinglass () is a substance obtained from the dried swim bladders of fish. It is a form of collagen used mainly for the clarification or fining of some beer and wine. It can also be cooked into a paste for specialised gluing purposes. Its origin is from the obsolete Dutch "huizenblaas" – "huizen" is a kind of sturgeon, and "blaas" is
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,