Harvesting and cleaning of the byssus beard

Harvesting of the noble pen shell in a 18th century print, and design of the trap. von Salis-Marschlins 1793
Harvesting of the noble pen shell in a 18th century print, and design of the trap. von Salis-Marschlins 1793
Johann Hieronymus Chemnitz (1730-1800), German naturalist and editor of a large book on shells writes: «An vielen Orten des mittelländischen Meeres wird nur bey stillen und heitern Wetter, wenn man die Steckmuscheln auf dem Sandgrunde kann stehend erblicken, ein Stock von oben in ihre immer offen stehende Oeffnung hineingestossen. Sogleich verschliesset sich vollends die Pinna und hält sich dadurch dergestalt am langen Stocke feste, dass sie damit umgedreht, von ihrem Standorte losgemacht und also herausgezogen werden kann.» In shallow water, divers brought up the shells, sometimes with the aid of a rope that was tied around the shell and then pulled up from the boat.

In the heigths of the sea-silk production in the 18th century, the noble pen shells were fished from a boat with various traps, tongs and forks, as shown in an engraving in the book of the Swiss naturalist Carl Ulysses von Salis-Marschlins in 1793 (English edition 1795). At the end of the 18th century he visited Southern Italy, wrote several reports and described in detail the extraction of the noble pen shell and the processing of sea-silk:


Sea-silk: cleaned and combed fiber beard of the noble pen shell.
Sea-silk: cleaned and combed fiber beard of the noble pen shell.
«This muscle is fished up with an iron, called pernonico, and the operation is thus performed. The instrument consists of two semicircular bars of iron -a -a fastened together at each end, but three inches distant from each other in the centre. From one end to the other, the diameter is nine inches, and the cavity, or half diameter, is from four to five inches. ... As soon as a pinna is discovered, the iron is slowly let down to the ground over the shell, which is then twisted round, and drawn out. When the fishermen has got a sufficient number of them, the shell is opened, and the silk, called at Taranto lana penna, is cut off the animal, and after being twice washed in tepid water, once in soap and water, and twice again in tepid water, is spread upon a table, and suffered to half dry in some cool and shady place. Whilst it is yet moist, it is softly rubbed and separated with the hand, and again spread upon the table to dry; and when thoroughly dry, it is drawn through a wide comb, and afterwards through a narrow one. Both these combs are of bone, and, except in size, are like hair combs. The silk thus combed belongs to the common sort, and is called extra dente; but that which is destined for finer works is again drawn through iron combs, or cards, there called scarde. It is then spun with a distaff and spindle, two or three threads of it being mixed with one of real silk; after which they knit not only gloves, stockings, and waistcoats, but even whole garments of it. When the piece is finished, it is washed in clean water, mixed with lemon juice; after which it is gently beaten between the hands, and finally smoothed with a warm iron. The most beautiful are of a brown cinnamon and glossy gold colour, producing a very rich and pleasing effect.»


Hackle, spindle and yarn wrapping tool to process sea-silk. Sardinia, ca 1930. Museum der Kulturen, Basel.
Hackle, spindle and yarn wrapping tool to process sea-silk. Sardinia, ca 1930. Museum der Kulturen, Basel.