This is the Great Pond Snail (Lymnaea stagnalis), a large freshwater snail commonly found in still or slow-moving bodies of water. Recognisable by its elongated, conical shell, which can reach up to 7 cm in length, this mollusc inhabits ponds, lakes, and ditches with abundant vegetation. 

Location:
Freshwater habitats across Europe, Asia, and North America. Common in UK ponds, lakes, and slow-flowing rivers.

Average Size:
Up to 7 cm in length.

Family:
Lymnaeidae (Pond Snails)

Species:
Lymnaea stagnalis

Ecological Role:
An important grazer and detritivore, the Great Pond Snail feeds on algae, decaying plant matter, and biofilm. It helps maintain water quality and provides a food source for fish, birds, and amphibians.

Reproduction:
Hermaphroditic; individuals possess both male and female reproductive organs. They lay jelly-like egg masses attached to submerged plants or other surfaces.

Conservation Status:
Not considered threatened. Widespread and abundant in suitable habitats, though local populations may be affected by pollution, habitat loss, or changes in water quality.

Collection Date:
Collected in Harford Bridges on 02/11/1900.