Eastern Pondmussel

Ligumia nasuta

DIAGNOSTICS 5

SHELL

  • size: mid-sized, maximum 100 mm. most under 70 mm
  • thickness: thin
  • shape: elongate, pointed posterior formed by relatively straight posterior slope edge and posterior third of ventral edge, giving a 'coffin' or 'wingtip shoe' shape to many individuals, especially younger ones. distinct posterior ridge
  • width: compressed to lightly inflated
  • surface: smooth
  • beaks: project slightly from hinge line. sculptures: 6 - 8 fine double loop bars
  • color/markings: olive-green to dark brown, faint narrow rays in young
  • sexual dimorphism: subtle. ventral margin slightly distended in females
  • pseudocardinal teeth: small, flattened
  • lateral teeth: small but well developped
  • nacre: silvery-white, pink or purple

Soft parts: foot white

Similar species/lookalikes: usually easy to identify by the distinct acute-angled posterior silhouette. Can resemble live specimens of black sandshell but posterior third of ventral margin rarely as straight. shells of this last species are also significantly thicker , and teeth are much larger. general shape also resembles eastern floater and paper pondshell, but shells of these species are much thinner and are devoid of any teeth.

Sources and Credits

  1. (c) Philippe Blais, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais
  2. (c) Matthew Ireland, all rights reserved, uploaded by Matthew Ireland
  3. (c) Smithsonian Environmental Research Center, some rights reserved (CC BY), http://commons.wikimedia.org/wiki/File:Ligumia_nasuta_(I1664)_0906_(38568291912).jpg
  4. Daderot, no known copyright restrictions (public domain), http://commons.wikimedia.org/wiki/File:Ligumia_nasuta_-_Springfield_Science_Museum_-_Springfield,_MA_-_DSC03465.JPG
  5. Adapted by Philippe Blais from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Ligumia_nasuta

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