Biodiversity & Conservation

Blunt gaper - Mya truncata

Mya truncata

Image Tim Siferd - Specimen of Mya truncata. Image width ca 7 cm.
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Distribution map

Mya truncata recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

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Mya truncata is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Mollusca Snails, slugs, mussels, cockles, clams & squid
Class Bivalvia Clams, cockles, mussels, oysters, and scallops
Authority Linnaeus, 1758
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Common around the coast of Britain, and recorded in several locations around the east and south coasts of Ireland.
Habitat information icon Habitat information Mya truncata burrows at considerable depths in mixed sand, sandy mud, or gravel substrata from the lower shore to about 70 m depth.
Text page icon Description The shell of Mya truncata can reach 7.5 cm in length, the anterior end is regularly rounded whilst the posterior end is abruptly blunt (truncated) with a large gape. The right valve is more convex than the left. The outer surface of the bivalve is off-white, and the outer layer of the shell (periostracum) is variable in colour from light olive to dark brown. The hinge of the left valve of the shell has a conspicuous spoon-shaped projection (chondrophore), to which the internal and external ligament is attached. The shell beaks are slightly posterior and directed inwards and touching. The pallial sinus is broad and deep with the lower margin irregularly confluent with the pallial line.
Identifying features
  • Bivalve abruptly blunt at posterior end of shell.
  • Shell length up to 7.5 cm.
  • Large gape at posterior end of shell.
  • Right valve more convex than the left.
  • Conspicuous spoon-shaped projection (chondrophore) on the hinge of the left valve.
  • Pallial sinus is broad and deep.
Additional information icon Additional information Mya truncata is smaller than Mya arenaria, with a blunt posterior end. The posterior of Mya arenaria is rounded.

This review can be cited as follows:

Susie Ballerstedt 2002. Mya truncata. Blunt gaper. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 22/05/2013]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=3840>