Shell Description
The shell of the Utah valvata snail is 4.5 mm high, and 4.5 mm width. The average size of adult Utah valvata snails is 4.32 mm.
The shell is turbinate in shape, thin, translucent and shining. It is a yellowish horn color at the apex, white or greenish white below the apex. The shell has four whorls which are convex, regularly increasing, minutely striate, the uppermost shouldered, with a single, well-marked carina which becomes obsolete on the body whorl. Turbinate shell form and an incipient carina (keel-shaped ridge) on the dorsal surface of the shell distinguishes Valvata utahensis from the morphologically similar Valvata humeralis.
The spire of the shell is obtusely elevated, and the apex is depressed. The suture is well impressed. The aperture of the shell is circular and slightly angled posteriorly. The lip of the aperture is simple, nearly continuous, and it is appressed to the body whorl.
The umbilicus is small and round; it is defined by a more or less obvious angle around the base of the shell.
The color of the operculum is light horn. The operculum is corneus, spirally multivolute, slightly produced posteriorly to conform to the shape of the aperture.
Read more about this topic: Utah Roundmouth Snail
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