Shell Description
The shell is thin, roundly ovate and very inflated, such that the last whorl comprises 90% of its volume.
The shell has a rounded and broad spire that pinches in steeply at the apex. The spire short, conic, very small compared with the body whorl.
There are 4–5 whorls with deep sutures between them. The whorls are convex, inflated, smooth and rapidly increasing. The body whorl is large and spreading. The surface is shining, lines of growth are fine, wavy, crowded, with occasionally a heavy ridge representing a rest period. Sutures are deeply impressed, channeled in some specimens.
The color of the shell is yellow, beige or tan.
The ear-shaped aperture, which contains no operculum, is around 5 times higher than the spire. The aperture is very large, ovate, occupying four-fifths of the length of the entire shell. It is rounded above and flaring in old specimens below. The peristome is thin and sharp. The columella is sigmoid with a plait across the middle, which is reflected over the umbilicus.
The umbilicus is either wide or covered. Usually the umbilicus is narrow, deep, nearly closed. The epidermis is sometimes marked by light and dark lines of color, alternating.
The shell of the species can grow to ~30 mm in height and 25 mm in width as a full grown adult. However, most individuals in a population only grow to approximately half the maximum size. The width of the shell is from 12–18 mm, and the height of the shell is 14–24 mm. The shell of Radix auricularia has a width to length ratio greater than 0.75.
Read more about this topic: Radix Auricularia
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