Description: Like a small, spireless Ampullaceana balthica but the voluminous mantle covers a good proportion of the shell in the living animal giving a spongy, wet feel when picked up. The mantle is never reflected over the shell in other pond snail species. Shell extremely thin, fragile, light brown. Very rare and declining. 12-15 mm.

World Distribution: A north European species distributed from the Alps to the Arctic Circle. In severe decline throughout its range and globally threatened. Distribution type: European Boreo-temperate (53).

Irish Distribution: Extremely localised in central and western Ireland. Still common in places along the Royal and Grand Canals in but evidently in decline even there. Formerly in the River Bann at Portadown, Co. Armagh (W.A. Greer, 1900), the Toome Canal, Co. Antrim (R. J. Welch, 1900) and the Newry Canal, Co. Armagh, but not seen at these places since the early decades of the twentieth-century and extinct in northern counties.

Ecology:

• Prefers hard bottoms in the slow-moving water of deeper rivers, lakes and canals
• Can be erratic in its appearances
• Probably intolerant of enrichment from agriculture (Kerney, 1999) which would in large part account for its present scarcity
• Conditions in the Grand Canal suggest a fairly low trophic status holds there at present i.e. little enrichment or eutrophication

Key Identification Features:

• A small bubble-shaped shell with very large, globular, body whorl and the spire almost completely recessed into this
• Shell thin, transparent and fragile and with a smooth, glossy surface
• Mantle of the living animal expands to cover the shell almost completely

Red list status:

• Endangered (EN).

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

iNaturalist: Myxas glutinosa at iNaturalist World Species Observations database.

GBIF data for Myxas glutinosa | Classification: Gastropoda, incertae sedis, Lymnaeidae, Myxas

Thumbnails for genus Myxas