Description

 Rissoa parva is a small snail up to 5 mm high and 3 mm wide. There are 7-8 whorls, which have a convex profile. It occurs in two forms, one with smooth whorls (var. interrupta) and one with vertical ridges (costae) on and after the 5th whorl. The shell is cream coloured to pale brown and has a lilac tint around the aperture. The body of the snail is yellow with black streaks and has long slender tentacles with an eye at the base of each.