Blunt gaper (Mya truncata)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help

Summary

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.

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.

Global distribution

Widely distributed over the whole of the Arctic and extends south to the Bay of Biscay in Europe, Massachusetts on the West Atlantic coast, and from Vancouver to Sachalin on the Pacific coast. Also reported from the coasts of Japan.

Habitat

Mya truncata burrows at considerable depths in mixed sand, sandy mud, or gravel substrata from the lower shore to about 70 m depth.

Depth range

-

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

Mya truncata is smaller than Mya arenaria, with a blunt posterior end. The posterior of Mya arenaria is rounded.

Listed by

- none -

Further information sources

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Bibliography

  1. Clay, E., 1966. Literature survey of the common fauna of estuaries. 12. Mya arenaria L., Mya truncata L. Imperial Chemical Industries Limited, Brixham Laboratory, BL/A/707.

  2. Fish, J.D. & Fish, S., 1996. A student's guide to the seashore. Cambridge: Cambridge University Press.

  3. Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.

  4. Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.

  5. Tebble, N., 1976. British Bivalve Seashells. A Handbook for Identification, 2nd ed. Edinburgh: British Museum (Natural History), Her Majesty's Stationary Office.

Datasets

  1. Centre for Environmental Data and Recording, 2018. IBIS Project Data. Occurrence dataset: https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  2. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  3. Cofnod – North Wales Environmental Information Service, 2018. Miscellaneous records held on the Cofnod database. Occurrence dataset: https://doi.org/10.15468/hcgqsi accessed via GBIF.org on 2018-09-25.

  4. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) data for Great Britain and Ireland - restricted access. Occurrence dataset: https://doi.org/10.15468/4bsawx accessed via GBIF.org on 2018-09-25.

  5. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) records for Great Britain and Ireland. Occurrence dataset: https://doi.org/10.15468/aurwcz accessed via GBIF.org on 2018-09-25.

  6. Kent Wildlife Trust, 2018. Kent Wildlife Trust Shoresearch Intertidal Survey 2004 onwards. Occurrence dataset: https://www.kentwildlifetrust.org.uk/ accessed via NBNAtlas.org on 2018-10-01.

  7. Merseyside BioBank., 2018. Merseyside BioBank (unverified). Occurrence dataset: https://doi.org/10.15468/iou2ld accessed via GBIF.org on 2018-10-01.

  8. National Trust, 2017. National Trust Species Records. Occurrence dataset: https://doi.org/10.15468/opc6g1 accessed via GBIF.org on 2018-10-01.

  9. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  10. Norfolk Biodiversity Information Service, 2017. NBIS Records to December 2016. Occurrence dataset: https://doi.org/10.15468/jca5lo accessed via GBIF.org on 2018-10-01.

  11. OBIS (Ocean Biodiversity Information System),  2023. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2023-09-27

  12. South East Wales Biodiversity Records Centre, 2018. SEWBReC Molluscs (South East Wales). Occurrence dataset: https://doi.org/10.15468/jos5ga accessed via GBIF.org on 2018-10-02.

Citation

This review can be cited as:

Ballerstedt, S. 2002. Mya truncata Blunt gaper. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 27-09-2023]. Available from: https://www.marlin.ac.uk/species/detail/1626

Last Updated: 15/11/2002