Rough Pen Shell, Pinna rudis

Pen sshells are large bivalves that attach themselves to the sea bed with strong, iridescent fibers known as byssus. This is the famous “golden fleece” of Greek myth; woven into a fine yarn called “sea silk” it has been used to make fine gloves, stockings and other items. The large animal is an important food item in many places, and is still fished from shallow water by divers wearing traditional suits with metal helmets. The Rough Pen Shell is found in the warmer parts of the northeast Atlantic Ocean and in the Mediterranean Sea.