Noble pen shells

Rome or elsewhere. Noble pen shells have become so scarce that in Italy and other Mediterranean countries they have the status of a protected species. Possession of a single freshly taken specimen can lead to a stiff fine. 

The Romans made direct use of byssal threads from noble pen shells. This ancient practice of using natural chemicals directly without modification remains the most widespread form of biotechnology. A recent innovation in this area is the expanding market for enzymes that function under extreme conditions. To appreciate the industrial value of these compounds, we must first briefly discuss enzymes and then consider some exotic organisms. 

There ate several other molluscs that can, on occasion, also produce pearls. The most mous are the conch and the baler, which both produce pearls of great value, althoi they are non-nacreous. Others, such as the horse conch and the noble pen shell, are less well known. Some molluscs produce concretions that are called pearls, but which tend to be curiosities rather than beautiful items. The most mous is the clam. 

Byssal thread has been used for many centuries as a very exclusive yam. The threads of the noble pen shell were the most used as they were a beautiful, iridescent, golden-bronxe colour and could reach 60 centimetres long. Hundreds of shells went into the production of, for example, one pair of gloves, as byssal thread is very fine and light. 

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