Mollusca : Gastropoda : Ellobiida : OtinidaeSnails and slugs

Otina ovata (T. Brown, 1827)

Ear-shaped snail

Otina ovata

Description: A tiny ear-shaped snail with a very large body whorl and minute spire. Shell surface purplish-brown and often with a chalky deposit. Animal pale and with short, stubby tentacles. Rock crevices on the upper shore. Local. 2.5-3 mm.

World Distribution: Has a very restricted distribution centred on the coasts of the British Isles and parts of western France. Distribution type: Oceanic Temperate (71).

Irish Distribution: An interesting member of the upper tidal crevice fauna, very localised in Ireland due to its dependence upon fissuring rock types. Recorded mainly from Co. Down, from Galway Bay and from Cos. Clare and West Donegal according to Stelfox (1911a).

Ecology:

  • Prefers foreshores or gullies in contact with the open sea, usually with a fine, silty-gravel substratum
  • Here it occupies silted crevices, usually within north or east-facing overhangs, 0.5m or so below the Pelvetia zone
  • Found more rarely under stones on silty gravel
  • The very restricted distribution is unusual in a supra-littoral organism and it can be regarded as near-endemic in Britain and Ireland

Key Identification Features:

  • A tiny ear-shaped shell with very large body whorl and minute spire
  • Shell covered with a purple-brown to brown periostracum, sometimes covered with a chalky deposit
  • Animal pale grey with short, stubby tentacles

Red list status:

  • Least concern (lc).

Distribution Map from NBN: Otina ovata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Otina ovata at iNaturalist World Species Observations database.

GBIF data for Otina ovata | Classification: Gastropoda, Ellobiida, Otinidae, Otina

Thumbnails for genus Otina

 Anderson, R., 2024. Otina ovata. (T. Brown, 1827). [In] MolluscIreland.
https://www2.habitas.org.uk/molluscireland/species.php?item=20. Accessed on 2024-12-26.