MolluscIreland - land and freshwater
  • Sphaerium corneum (Linnaeus 1758) Horny orb mussel
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Sphaerium corneum
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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A small, broadly oval, tumid bivalve coloured yellowish, grey or shades of brown. Umbos rounded, more or less central. Shell pores are few and irregularly dispersed. Widespread and often abundant.

Key characteristics

  • A small, broadly oval, tumid bivalve
  • Surface silky with very fine, irregular concentric growth ridges
  • Coloured yellowish, grey or shades of brown
  • Umbos rounded, more or less central
  • Pores present on the shell but these are few in number and irregularly dispersed

Size

9-11 mm.

World Distribution

Very widespread in Europe and across Asia to North America. Distribution type: Circumpolar Wide-temperate (66).

Irish Distribution

Widespread and usually abundant throughout but more thinly distributed to the west and north.

Ecology

  • Abundant in a variety of freshwaters but especially lakes and rivers of moderate hardness
  • Commonest in bottom sediments but it will readily climb macrophytes
  • Rarely found in swiftly flowing water although abundant in hill streams in one or two of the Antrim Glens

Red List status

  • Least concern (lc).

Wikipedia link

Wikipedia page for Sphaerium corneum

 Anderson, R., (2016). Sphaerium corneum (Linnaeus 1758). [In] MolluscIreland.
http://www.habitas.org.uk/molluscireland/species.asp?ID=157 Accessed on 2017-10-19.