Higher Classification: > Kingdom Animalia > Phylum Mollusca > Class Bivalvia > Subclass Heterodonta > Infraclass Euheterodonta > Order [unassigned] Euheterodonta > Superfamily Solenoidea > Family Pharidae > Genus Ensis

Ensis directus (Conrad, 1843)

Rank: Species
Taxon Status: accepted

Relationships towards this taxon

Genus group names

EnsisSchumacher, 1817accepted genus name
Ensatella Swainson, 1840 synonym

Species group names

Ensis americanus (Gould, 1870) synonym
Solen directus Conrad, 1843 synonym
Solen ensis var. americana Gould & Binney, 1870 synonym

Vernaculars (+) (-)

 Danish: Amerikansk knivmusling sources: PESI (A Pan-European Species directories Infrastructure) focal points
 English: American jack knife clam; Atlantic jack knife clam sources: Hayward, P.J.; Nelson-Smith, A.; Shields, C. (1996). Collins pocket guide: sea shore of Britain and Europe. Collins pocket guides. Harper-Collins Publishers: London, UK. ISBN 0-00-219955-6. 352 pp.;Dewarumez, J.-M.; Gévaert, F.; Massé, C.; Foveau, A.; Desroy, N.; Grulois, D. (2011). Les espèces marines animales et végétales introduites dans le bassin Artois-Picardie . UMR CNRS 8187 LOG/Agence de l’Eau Artois-Picardie: Douai. 138 pp.
 French: couteau américain; couteau droit sources: Strandvondsten van Gravelines tot Nieuwpoort. Ecogids Tjiftjaf;Chabot, R. & Rossignol, A. 2003. Algues et faune du littoral du Saint-Laurent maritime: Guide d'identification. Institut des sciences de la mer de Rimouski, Rimouski; Pêches et Océans Canada (Institut Maurice-Lamontagne), Mont-Joli. 113 pages.
 German: Amerikanische Scheidenmuschel; Amerikanische Schwertmuschel


basis of record

Cosel R. von, 2009. The razor shells of the eastern Atlantic, part 2. Pharidae II: the genus Ensis Schumacher, 1817 (Bivalvia, Solenoidea). Basteria, 73: 9-56

additional source

Brunel, P., Bosse, L. & Lamarche, G. (1998). Catalogue of the marine invertebrates of the estuary and Gulf of St. Lawrence. Canadian Special Publication of Fisheries and Aquatic Sciences, 126. 405 p.

additional source

Trott, T.J. 2004. Cobscook Bay inventory: a historical checklist of marine invertebrates spanning 162 years. Northeastern Naturalist (Special Issue 2): 261 - 324.

additional source

Vierna J., Cuperus J., Martínez-Lage A., Jansen J.M., Perina A., Van Pelt H. & González-Tizón, A.M. (2014) Species delimitation and DNA barcoding of Atlantic Ensis (Bivalvia, Pharidae). Zoologica Scripta 43(2): 161–171. [Published online 3 September 2013; Code-compliant paper version published March 2014]

additional source

Meinkoth, N.A. 1981. Field guide to North American seashore creatures. The Audubon Society. Alfred A. Knopf. New York. 799 p.

additional source

Streftaris, N.; Zenetos, A.; Papathanassiou, E. (2005). Globalisation in marine ecosystems: the story of non-indigenous marine species across European seas. Oceanogr. Mar. Biol. Ann. Rev. 43: 419-453

additional source

Turgeon, D. D., W. G. Lyons, P. Mikkelsen, G. Rosenberg, and F. Moretzsohn. 2009. Bivalvia (Mollusca) of the Gulf of Mexico, Pp. 711–744 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, Colleg

additional source

Vierna J., Jensen K.T., González-Tizón A.M. & Martínez-Lage A. (2012) Population genetic analysis of Ensis directus unveils high genetic variation in the introduced range and reveals a new species from the NW Atlantic. Marine Biology 159(10): 2209–2227. [Published online 31 July 2012; Code-compliant version published in October 2012]





External Links

Biodiversity Heritage Library (117 publications)
Barcode of Life (1 barcode)
USNM Invertebrate Zoology Mollusca Collection
Delivering Alien Invasive Species Inventories for Europe (DAISIE)
European Network on Invasive Alien Species (NOBANIS) - Ensis americanus
GenBank (596 nucleotides; 183 proteins)


von Cosel, R.; Gofas, S. (2014). Ensis directus. In: Costello, M.J.; Bouchet, P.; Boxshall, G.; Arvantidis, C.; Appeltans, W. (2014) European Register of Marine Species, accessed through PESI at http://www.eu-nomen.eu/portal/taxon.php?GUID=urn:lsid:marinespecies.org:taxname:140732




 Present  Absent  Doubtful  Native  Introduced  Naturalised  Invasive  Managed  No data


marine, brackish, not fresh, not terrestrial


no data

Provided by

logo erms



Last modified

2009-09-05 by Rudo von Cosel

Your feedback

click here

Creative Commons License This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License

Your e-mail address:

Your message: