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 (in particular Pinna nobilis).[1] The byssus is used by the mussel to attach itself to the sea bed.[2]
Sea silk was produced in the Mediterranean region from the large marine bivalve mollusc Pinna nobilis until early in the 20th century. The animal, whose shell is sometimes almost a metre long, adheres itself pointed end down to rocks in the intertidal zone using a tuft of very strong thin fibres. These byssi or filaments (which can be six centimetres long) are spun and, when treated with lemon juice, turn a golden colour, which never fades.[3]
The cloth produced from these filaments can be woven even more finely than silk, and is extremely light and warm; it was said that a pair of women's gloves made from the fabric could fit into half a walnut shell and a pair of stockings in a snuffbox.[4][5] The cloth attracts clothes moths, the larvae of which will eat it.
Pinna nobilis is also sometimes gathered for its edible flesh and occasional pearls of fair quality.