Sea Silk

Sea silk is an extremely fine, rare and valuable fabric that is made from the long silky filaments or byssus secreted by a gland in the foot of pen shells (particularly Pinna nobilis). The byssus is used by the clam to attach itself to the sea bed.

Sea silk was produced in the Mediterranean region from the large marine bivalve mollusc, Pinna nobilis until early in the 20th century. The shell, which is sometimes almost a metre long, adheres itself to rocks with a tuft of very strong thin fibres, pointed end down, in the intertidal zone. These byssus or filaments (which can be up to 6 cm long) are then spun and, when treated with lemon juice, turn a golden colour, which never fades.

The cloth produced from these filaments can be woven even finer than silk, and is extremely light and warm; however, it attracts clothes moths, the larvae of which will eat it. It was said that a pair of women's gloves could fit into half a walnut shell and a pair of stockings in a snuffbox. The mollusc is also sought for its flesh and occasionally has pearls of fair quality.