The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Habitat & Distribution
This species lives in interstitial, rock and crevice habitats on the upper shore. It has a
south-western distribution in the British Isles and its small size and cryptic habitat results in it being rarely recorded living. At present (2008), living specimens are recorded from north and south Devon, Dorset, Pembrokeshire, the Isle of Wight and Cornwall. Until recently (1998) it was only known in Cornwall from dead shells from Sennen Cove, the Lizard Peninsula and at Porthcurno. In 1998/1999 live specimens were recorded from Poldhu Cove and several other sites on the west coast of the Lizard Peninsula and at Sennen Cove. Fresh shells were also found at Pont Pill in the Fowey estuary. Six sites were also found on the Isles of Scilly (St. Mary' s, St. Agnes, Gugh and Tresco). These finds suggest that the Isles of Scilly may be a stronghold for this species in southern Britain. It is currently (2008) known from at least 40 sites in Britain (Killeen & Light, 2002) and was recently removed from Schedule 5 of the Wildlife & Countryside Act. Living specimens have been found at a total of 31 sites around the Cornish coastline and the Isles of Scilly.
As a member of the crevice fauna, there is probably no threat, but in saltmarsh sites it is much more vulnerable.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.