Description: This is a small snail up to 12 mm long by 5 mm wide. It has a thin conical shell with 5-6 smooth, swollen whorls. It is usually a pale horn colour with 2-4 red-brown bands on the last whorl and 2 coloured bands on the upper whorls, which become more faint towards the apex of the shell, although banding can be very faint or absent in some individuals. The apex is generally purple in colour. The umbilicus (beside the opening) is very obvious, V-shaped and has a prominent chink or groove. It has two long tentacles at its head and two short, flat tentacles towards the rear of the foot. Can sometimes be found in very large numbers.

Habitat: Usually found on seaweeds or Zostera from low water to around 40 m depth. Can tolerate lower salinity.

Distribution: Recorded all around Britain and Ireland.

Similar Species: There are other small snails which could potentially be confused with these species, including other Lacuna, shell shape as well as the shape of the umbilicus can distinguish it from others.

Key Identification Features:

• Thin conical shell with smooth, swollen whorls.
• Apex usually purple in colour.
• Banding usually present, becoming more faint towards apex.
• Obvious v-shaped umbilicus with a prominent chink or groove.

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

iNaturalist: Lacuna vincta at iNaturalist World Species Observations database.

GBIF data for Lacuna vincta

WoRMS: Lacuna vincta at World Register of Marine Species. Accepted name: Lacuna vincta (Montagu, 1803). AphiaID: 140170.

Classification: Biota; Animalia; Mollusca; Gastropoda; Caenogastropoda; Littorinimorpha; Littorinoidea; Littorinidae; Lacuninae; Lacuna