Taxon profile


Pen Shell
Pinna nobilis Linnaeus, 1758

kingdom Animalia - animals »  phylum Mollusca - mollusks »  class Bivalvia - bivalves »  order Ostreida »  family Pinnidae »  genus Pinna


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Habitat: it lives into the sand near Posidonia oceanica fixed by its long byssus, embedded vertically. Distribution: common all over the Mediterranean.
Notes: it is among the biggest bivalves of the Mediterranean. Shell triangular stretched in form, brittle, valves opened posteriorly. Valves external surface covered by lamellae squamous, foliaceus, tubular, concentric becoming bigger and bigger towards the posterior part. In the anterior part there are about 20 longitudinal striae alternate between strong and weak ones. Inside of valves red-brown in colour with two pearly areas starting from umbones up to the middle of the shell. Externally uniform light brown in colour. It is present a fine periostracum. Ligament takes up about two-thirds of total length. Anteriorly it can be noted one small muscle scar near umbo, while another scar bigger and roundish can be noted in the inferior dorsal side of the pearly part. Byssus made by many long silky filaments al-lowing the shell to embed into the bottom. There are many varieties in form assigned to this species by several authors, particularly by De Gregorio (1885), B.D.D. (1890), Pallary (1906, 1919). In its pallial cavity either some small crabs such as Pinnotherespisum or Pinnotheres pinnotheres or shrimps of the species Pontonia pinnophylax find often a refuge. The small pearls, that sometimes can be found inside this large bivalve, have not any commercial value. The adult specimens average measures are around 40-50 cm but there were found specimens of 80 cm in length too.
Scaperrotta, M. ,Bartolini, S. & Bogi, C., 2009. Accrescimenti, Vol. 2. Stages of growth of marine molluscs of the Mediterranean Sea.
Author: Jan Delsing

Links and literature

EN Galli C.: WMSDB - Wolrdwide Mollusc Species Data Base July 10, 2013 [] [as Pinna nobilis Linnaeus, 1758]
Data retrieved on: 23 November 2013
CZ Pfleger V. (1999): České názvy živočichů III. Měkkýši (Mollusca), Národní muzeum, (zoologické odd.), Praha, 108 pp. [as Pinna nobilis LINNÉ, 1758]
Data retrieved on: 11 November 2013
IT Repetto G., Orlando F. & Arduino G. (2005): Conchiglie del Mediterraneo, Amici del Museo "Federico Eusebio", Alba, Italy [as Pinna nobilis Linné, 1758]
EN Petović S., Gvozdenović S., Ikica Z. (2017): An Annotated Checklist of the Marine Molluscs of the South Adriatic Sea (Montenegro) and a Comparison with Those of Neighbouring Areas, Turkish Journal of Fisheries and Aquatic Sciences 17: 921-934 [as Pinna nobilis (Linnaeus, 1758)]

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