Gaping file shell (Limaria hians)

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



The edge of the fleshy mantle bears numerous conspicuous, red and orange filamentous tentacles. The shell is thin, solid, equivalve and oval in outline, tapering towards the beaks, and usually about 2.5 cm in length but occasionally reaching 4 cm. The beaks bear an 'ear' like projection on each side, the anterior 'ear' being more prominent. The shell gaps on both sides. The shell is white in young specimens becoming whitish-brown with age. The shell bears clear growth steps and ca 50 radiating ribs that extend to a crenulate margin. When disturbed this species can swim actively using jets of water expelled by 'clapping' its shells together and a rowing motion of its tentacles.

Recorded distribution in Britain and Ireland

Patchy records from off Plymouth Sound, Skokholm, southern Isle of Man, western coasts and lochs of Scotland, and Mulroy Bay, Northern Ireland.

Global distribution

Recorded from the Lofoten Isles Norway, Iceland, south to the Iberian Peninsula, the Mediterranean, Canary Isles and Azores.


Found from low water to ca 100 m on coarse sand, gravel, broken shells and stones. It may occupy 'nests' of byssus threads among rubble, under stones or in the holdfasts of laminarians. When abundant, the 'nests' may coalesce to form a carpet or reef over shell-sand, which may provide a substratum for kelps.

Depth range

Lower shore to ca 100m

Identifying features

  • Mantle edge bears numerous, conspicuous red and orange contractile tentacles.
  • Hinge line drawn out into 'ears'.
  • Shell, oval in outline, inequilateral, usually white and bearing ca 50 radiating ribs.
  • Shell gapes prominently on each side.
  • Builds byssus nests.

Additional information

No text entered

Listed by

- none -


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  7. Hall-Spencer, J.M. & Moore, P.G., 2000b. Limaria hians (Mollusca: Limacea): A neglected reef-forming keystone species. Aquatic Conservation: Marine and Freshwater Ecosystems, 10, 267-278.

  8. Hall-Spencer, J.M. & Moore, P.G., 2000c. Scallop dredging has profound, long-term impacts on maerl habitats. ICES Journal of Marine Science, 57, 1407-1415.

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  12. JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line]

  13. MBA (Marine Biological Association), 1957. Plymouth Marine Fauna. Plymouth: Marine Biological Association of the United Kingdom.

  14. Minchin, D., 1995. Recovery of a population of the flame shell, Lima hians, in an Irish bay previously contaminated with TBT. Environmental Pollution, 90, 259-262.

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

  16. Waren, A., 1989. New and little known Mollusca from Iceland. Sarsia, 74, 1-28.


  1. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset accessed via on 2018-09-25.

  2. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) data for Great Britain and Ireland - restricted access. Occurrence dataset: accessed via on 2018-09-25.

  3. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) records for Great Britain and Ireland. Occurrence dataset: accessed via on 2018-09-25.

  4. Fenwick, 2018. Aphotomarine. Occurrence dataset Accessed via on 2018-10-01

  5. NBN (National Biodiversity Network) Atlas. Available from:

  6. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-05-23


This review can be cited as:

Tyler-Walters, H., 2008. Limaria hians Gaping file shell. 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 23-05-2024]. Available from:

Last Updated: 17/04/2008