Description: A broad, operculate shell with loose coiling and an open umbilicus, forming a squat cone. Surface yellow-brown, matt, with fine radial striae. Lives on the bottom in large lakes and rivers. 4.5-6 mm.

World Distribution: Found across the whole of mainland Europe and Siberia to Pacific coastsof Asia. Distribution type: Eurasian Wide Temperate (65).

Irish Distribution: Widespread and an important constituent of the diet of wintering wildfowl on larger lakes such as Lough Neagh (Winfield & Winfield, 1994). Rare or absent in the extreme west, south-west and north.

Ecology:

• Usually on the bottom, in slow-flowing, weed-free water and to considerable depths in lakes
• Tolerates soft water in large lake systems but rare in small habitats and not in acid or dystrophic conditions

Key Identification Features:

• A broader than tall, medium-sized operculate shell with a narrow, deep umbilicus
• Yellow-brown in colour but often darker from deposits
• Surface with fine radial striae which are more pronounced in var. alpestris Küster found in Loughs Neagh and Erne
• Live animal possesses a feathery external gill

Red list status:

• Least concern (lc).

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

iNaturalist: Valvata piscinalis at iNaturalist World Species Observations database.

GBIF data for Valvata piscinalis | Classification: Gastropoda, incertae sedis, Valvatidae, Valvata

Thumbnails for genus Valvata