Term used in ancient times for a fiber (and by extension, fabric) highly prized for its fineness, which was once the basis of a small textile manufacturing industry centered around the Italian Mediterranean. 'Byssus' was used to describe a variety of substances, leading to confusion and controversy over its proper denotation. Some scholars view byssus as simply a generic term covering a host of fiber proteins and products manufactured from them; others insist that the term specifically describes shellfish derived 'sea-silk'. Usage extends to both. (en)