MolluscIreland - land and freshwater
  • Vertigo (Vertigo) pusilla O. F. Müller, 1774 Wall Whorl Snail
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Vertigo (Vertigo) pusilla
© Dr Roy Anderson
Vertigo (Vertigo) pusilla
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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Sinistral. Larger than the only other sinistral species of Vertigo, V. angustior. Shell yellowish-brown to mid brown, nearly smooth but with fine growth lines i.e. paler and smoother than angustior. Aperture filled with 6-9 denticles.

Key characteristics

  • Sinistral but larger than V. angustior
  • Shell nearly smooth, yellowish-brown
  • Apertural denticles 6-9: 2 parietal; 2 columellar; 3 palatal, two of which are very long
  • Very rare, mainly on old, undisturbed limestone scrub or rough pasture

Size

1.7 - 2.0 mm.

World Distribution

Distribution European boreo-temperate (53).

Irish Distribution

Very localised and rare. Widespread as a subfossil in sand dune deposits on the north coasts of Antrim and Londonderry (Welch, 1898). Most of the surviving Irish sites are in Co. Clare on Carboniferous limestone. In the northern half of Ireland seen recently only at Sheskinmore Lough, West Donegal. Historically recorded from Whitepark Bay, Co. Antrim (Standen, 1897), Grogan's Glen, Belfast (specimens in UM, G. C. Hyndman, 1833; MN2048) and at Colin Glen, Belfast (W. Thompson, 1837) but appears gone from these localities now.

Ecology

  • Found in sheltered and warm, rather open sites in woods, scrub or undisturbed rough pasture
  • South-facing chalk or limestone slopes and sand dunes are also favoured
  • Certainly in decline but possibly under-recorded

Red List status

  • Endangered (EN)

Wikipedia link

Wikipedia page for Vertigo pusilla

 Anderson, R., (2016). Vertigo (Vertigo) pusilla O. F. Müller, 1774. [In] MolluscIreland.
http://www.habitas.org.uk/molluscireland/species.asp?ID=199 Accessed on 2017-10-20.