Pinna nobilis, known by the common name noble pen shell and fan mussel, is a large species of Mediterranean clam, a marine bivalve mollusc in the family Pinnidae, the pen shells.[* Pinna gigas Chemnitz]
It reaches up to of shell length.[Zavodnik, D., Hrs-Brenko, M., & Legac, M. (1991). Synopsis of the fan shell P. nobilis L. in the eastern Adriatic sea. In the C. F. Boudouresque, M. Avon, & V. Gravez (Eds.), Les Especes Marines a Proteger en Mediterranee (pp. 169–178). Marseille, France: GIS Posidonie publ.] It produces a rare manganese-containing porphyrin protein known as pinnaglobin.
Description
The
bivalve shell is usually long,
[Acquario di Genova (2006). Pinna nobilis. Retrieved 15 September 2014.] but can reach .
[ Its shape differs depending on the region it inhabits. Like all pen shells, it is relatively fragile to pollution and shell damage. It attaches itself to rocks using a strong byssus composed of many silk-like threads which used to be made into cloth. The animal secretes these fibres from its byssus gland; they consist of keratin and other proteins and may be as long as . The inside of the shell is lined with nacre.][Tyndale (1849): The Island of Sardinia, including Pictures of the Manners and Customs of the Sardinians, . . . Three Volumes. John Warre Tyndale. London: Richard Bentley. pp. 77–79.]
As with other members of its genus, Pinna nobilis hosts symbiotic which live inquiline; in this case it is the Palaemonidae Pontonia and the Pinnotheridae Nepinnotheres pinnotheres.
Right and left valve of the same specimen:
Pinna nobilis 001.jpg|Right valve
Pinna nobilis 002.jpg|Left valve
Distribution
This species is Endemism to the Mediterranean Sea, where it lives offshore at depths ranging between .[Butler, A., Vicente, N., De Gaulejac, B. (1993). Ecology of the pteroid bivalves P. nobilis bicolor Gmelin and P. nobilis L. Marine Life, 3(1–2), 37–45.] It could be found buried beneath soft-sediment areas (fine sand, mud, often Anoxic waters).
Human relevance
This species is the origin of sea silk, which was made from the byssus of the animal.[Hill, John E. (2009) Through the Jade Gate to Rome: A Study of the Silk Routes during the Later Han Dynasty, 1st to 2nd centuries CE. John E. Hill. BookSurge, Charleston, South Carolina. . See Section 12 plus "Appendix B – Sea Silk". pp. 468–476.]
Threats
In 2016, an outbreak of one disease caused the mortality of 99% of its population in Spain. The cause of the disease was a newly discovered pathogen, Haplosporidium pinnae, which still poses a serious threat to the survival of the species. By 2019, mortality spots had been detected in Greece, Croatia, Turkey, Tunisia, France and Morocco. In the Trieste area, considerable efforts have also been made to conserve the deposits since 2020.[Chiara D'Incà "Nel Golfo di Trieste l'epidemia sterminante della Pinna nobilis" In: Trieste All News 25.1.2020.][ Il Piccolo: Almost disappeared in Miramare for years, the Pinna nobilis reappears in Istria] In the past, Pinna nobilis faced extinction, due in part to fishing, incidental killing by trawling and anchoring, and the decline in seagrass fields; pollution kills eggs, larvae, and adult mussels.
The noble pen shell has been listed as an endangered species in the Mediterranean Sea. The European Council Habitats Directive 92/43/EEC, on conservation of natural habitats and the wild fauna and flora, proclaims that P. nobilis is strictly protected (by the Annex IV of EEC, 1992) – all forms of deliberate capture or killing of fan mussel specimens are prohibited by law.[Centoducati, G., Tarsitano, E., Bottalico, A., Marvulli, M., Lai, O., Crescenzo, G. (2006). Monitoring of the Endangered Pinna nobilis Linee, 1758 in the Mar Grande of Taranto (Ionian Sea, Italy). In the Environ Monit Assess (2007) 131:339–347.]
As part of the Costa Concordia disaster recovery effort in Italy in 2012, a group of about 200 Pinna nobilis was relocated to a nearby area due to the threat posed by subsequent engineering work.[ Reuters video about the Pinna nobilis relocation]
The byssus of Atrina pectinata, a shell of the same family, has been used in Sardinia as a substitute for Pinna nobilis, to weave sea silk.
Protection
Pinna nobilis is sensitive to exceptional pollution. Many die due to anchoring; additionally, illegal extraction, which has been prohibited in Croatia since 1977, is still present. It has been placed on the list of strictly protected species in Croatia. Any extraction of P. nobilis out of the sea is heavily fined.
==Gallery==
See also
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List of animals that produce silk
Further reading
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Hill, John E. 2004. The Peoples of the West. A draft annotated translation of the 3rd century Weilüe – see Section 12 of the text and Appendix D.
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Laufer, Berthold. 1915. "The Story of the Pinna and the Syrian Lamb", The Journal of American Folk-lore 28.108:103–128.
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McKinley, Daniel L. 1988. "Pinna and Her Silken Beard: A Foray Into Historical Misappropriations". Ars Textrina: A Journal of Textiles and Costumes, Vol. Twenty-nine, June 1998, Winnipeg, Canada. pp. 9–223.
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Maeder, Felicitas 2002. "The project Sea-silk – Rediscovering an Ancient Textile Material." Archaeological Textiles Newsletter, Number 35, Autumn 2002, pp. 8–11.
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Maeder, Felicitas, Hänggi, Ambros and Wunderlin, Dominik, Eds. 2004. Bisso marino : Fili d'oro dal fondo del mare – Muschelseide : Goldene Fäden vom Meeresgrund. Naturhistoriches Museum and Museum der Kulturen, Basel, Switzerland. (In Italian and German).
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Schafer, Edward H. 1967. The Vermillion Bird: T'ang Images of the South. University of California Press.
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Turner, Ruth D. and Rosewater, Joseph 1958. "The Family Pinnidae in the Western Atlantic" Johnsonia, Vol. 3 No. 38, 28 June 1958, pp. 285–326.
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R. Tucker Abbott & S. Peter Dance, 1982, "Compendium of seashells: a color guide to more than 4,200 of the world's marine shells", E.P. Dutton Inc., New York. .
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