Relevant Synonyms - Misidentification -  drawing: Tuvia Kurz

SHORT DESCRIPTION Shell inequilateral, thin and fragile. Shape cylindrical, elongated. The anterior end short and rounded the posterior elongated, and slightly gaping. There is a well-defined lunule in front. Sculpture of distinct growth lines and strong radiating ribs. Ribs at the posterior end crowded and faint; at anterior end elevated and widely spaced. color : chalky white to dirty cream yellow. common size : 25-80 mm in length. DISTINGUISHING CHARACTERISTICS Cardinal teeth in hinge distinguish it from other species in Pholadidae. It bears a superficial resemblance to the white piddock Barnea candida but has two teeth in the rv and three in the lv whereas B. candida has none. BIOLOGY / ECOLOGY Bores mechanically into hard clay, limestone and chalk, consolidated mud. habitat : sand substrata from the lower intertidal zone down to 8 m.

1st Mediterranean record Ewoikos, Greece, 1994. DISTRIBUTION Worldwide: Western Atlantic, from Gulf of St. Lawrence to Uruguay (Abbott, 1974); introduced to Northern Europe (Wouters, 1993). Mediterranean: first record in Greece, southern Aegean (Delamotte and Vardala-Theodorou, 1994). The record in the western Mediterranean from Spain to Tunisia (Poutiers, 1987) is non documented and therefore disputed. ESTABLISHMENT SUCCESS Extremely rare; two records based each on a single specimen. speculated reasons for success : - MODE OF INTRODUCTION Accidentally imported into southern England with the American oyster Crassostrea virginica. From there it extended its range to Atlantic coasts of Europe. First reported in Denmark in 1905, it became later common in Kattegat from where it has spread to the coasts of Belgium and the Netherlands (ICES, 1972). It occurrence in Greece is related to shipping rather than to marine farming activities. IMPORTANCE TO HUMANS None. No serious harm to the environment in UK. However, in Belgium and the Netherlands it has almost completely replaced the native species Pholas candida.

KEY REFERENCES Abbott R.T., 1974. American Seashells. The marine mollusca of the Atlantic and Pacific coast of North America. 2nd edit., Van Nostrand, New York. 663 p. + 24 pl. Delamotte M. and Vardala-Theodorou E., 1994. Shells from the Greek seas. The Goulandris National History Museum, Athens, 313 p. ICES, 1972. Report of the working group on introduction of non-indigenous marine organisms. Cooperative Research Reports, 32, 59 p.   Wouters D., 1993. 100 jaar na de invasie van de Amerikaanse boormossel: de relatie Petricola pholadiformis Lamarck, 1818 / Barnea candida Linnaeus, 1758. De Strandvlo, 13(1): 3-39. FEEDBACK / COMMENTS TO AUTHORS

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