Marine Biology

, Volume 159, Issue 10, pp 2209–2227 | Cite as

Population genetic analysis of Ensis directus unveils high genetic variation in the introduced range and reveals a new species from the NW Atlantic

  • Joaquín ViernaEmail author
  • K. Thomas Jensen
  • Ana M. González-Tizón
  • Andrés Martínez-Lage
Original Paper


We report current genetic variation of populations of the razor shell Ensis directus (Conrad 1843) (Mollusca: Bivalvia: Pharidae) in native (North American) and introduced (European) ranges using nuclear and mitochondrial sequence-based markers. We expected less variation within the introduced range, especially considering the frequent mass mortality events observed in Europe since the species was recorded for the first time in 1978. However, we found higher variation in Europe. The possible significance of temporal fluctuations of genetic variation, limited effect of random genetic drift, and multiple introductions are discussed. Interestingly, the multiple-introduction hypothesis contrasts with the gradual colonisation of European coastal waters but is supported by trained clustering analysis and by the intensity of transatlantic shipping. Genetic and morphometric evidence strongly supports that examined individuals from a supposed E. directus population from Newfoundland (Canada) belong to a separate species. This new Ensis is formally described here and named E. terranovensis n.sp.


Adenine Nucleotide Translocase Mass Mortality Event Adductor Scar European Individual Pallial Sinus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Museo Nacional de Ciencias Naturales, Madrid, Spain


Muséum national d’Histoire naturelle, Paris, France


Zoologisk Museum—Københavns Universitet, Copenhagen, Denmark


Canadian Museum of Nature, Ottawa-Gatineau, Canada



We are very grateful to Rudo von Cosel for his support and his drawing of E. terranovensis holotype, and to the following colleagues who helped us in some way or another during the execution of this work: André Martel, Anja Schulze, Barbara Buge, David Palmer, Diego Fonataneto, Ferruccio Maltagliati, Horacio Naveira, Jean-Marc Gagnon, Jean-Marie Dewarumez, Jeroen Goud, Jukka Corander, Manuel Pimentel, Mark Graham, Marta Vila, Neus Marí, Nicolas Puillandre, Ole S. Tendal, Paul Dansey, Philip Sargent, Rafael Araújo, Ray J. Thompson, Robert O’Donnell, Stephen T. Tettelbach, Tim Sheehan, and Tom Schioette. We would also like to thank two anonymous reviewers for critical and helpful comments. JV has been supported by a ‘María Barbeito’ fellowship and a travel grant, both from the Consellería de Economía e Industria, Xunta de Galicia (Spain) and the European Social Fund.

Supplementary material

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Supplementary material 1 (PDF 167 kb)
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Supplementary material 2 (PDF 68 kb)
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Supplementary material 4 (XLS 52 kb)
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Supplementary material 5 (PDF 1526 kb)


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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Joaquín Vierna
    • 1
    • 2
    Email author
  • K. Thomas Jensen
    • 3
  • Ana M. González-Tizón
    • 1
  • Andrés Martínez-Lage
    • 1
  1. 1.Department of Molecular and Cell Biology, Evolutionary Biology Group (GIBE)Universidade da CoruñaA CoruñaSpain
  2. 2.AllGeneticsA CoruñaSpain
  3. 3.Marine Ecology, Department of BioscienceAarhus UniversitetAarhus CDenmark

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