Clanculus plebejus
A small Australian top snail with a depressed, colorfully ribbed shell.
Clanculus plebejus, called the plebeian clanculus, is a marine gastropod mollusk belonging to the family Trochidae, which includes the top snails. Its shell, measuring 6 to 11 mm, is small, depressed, and has an umbilicus. Coloration ranges from pinkish brown to gray or yellow, with ribs marked by black and white dots that often create radiating lines on the upper surface and zigzag patterns below, where yellow replaces pink in the background. The spire is low and conical, with an acute apex. The roughly five whorls are coarsely lirate, and the sutures are slightly channeled. The body whorl is obtusely angled at the periphery, with four coarse, somewhat beaded spiral ridges on its upper surface: the top two are close together, the third is separated by wide gaps above and below, and the fourth, at the periphery, usually consists of two ridges side by side. The spaces between these ridges contain many fine spiral striae and sharp microscopic growth lines. The convex base has six to nine smooth concentric striae, with numerous microscopic striulae in the intervals. The aperture is rounded and oblique, with thickened outer and basal margins that are very finely crenulated inside. The columella is oblique, not twisted above, and does not enter the umbilicus but attaches to its side; its front edge is nearly straight and toothed at the base. The wide umbilicus is shallow, with a somewhat toothed margin. This species is endemic to Australia, found off New South Wales, South Australia, Tasmania, Victoria, and Western Australia.
Quick Facts
- Taxon
- Clanculus plebejus
Facts from the source article.
Lore & Background
The shell of Clanculus plebejus is small, depressed, and umbilicate, with a low-conic spire and acute apex. Its about 5 whorls are coarsely lirate, with subcanaliculate sutures. The body whorl is obtusely angular at the periphery, its upper surface encircled by 4 coarse, somewhat beaded lirae, the upper two contiguous, the third separated by wide intervals, and the fourth peripheral, often formed of two ridges close together. The interstices bear numerous fine spiral striae and sharp microscopic incremental striae. The convex base is concentrically sculptured with 6 to 9 smooth striae, between which very numerous microscopic striulae revolve. The rounded aperture is oblique, with outer and basal margins thickened and very minutely crenulated within. The columella is oblique and not tortuous above, nor entering the umbilicus, but inserted upon its side; the front edge is nearly straight, denticulate at the base. The wide umbilicus is not very deep, its margin somewhat denticulate.
Reader's Guide
Clanculus plebejus is documented in numerous Australian malacological works from the mid-19th century onward, including contributions by Philippi, Adams, Angas, Tenison-Woods, and others. Its distribution is restricted to Australian waters, specifically off New South Wales, South Australia, Tasmania, Victoria, and Western Australia. The species is referenced in major regional checklists and surveys, such as those by Hedley, May, Cotton, Macpherson & Gabriel, and Wilson. The shell's distinctive coloration—pinkish brown, gray, or yellow with black and white articulated ribs—and its detailed sculptural features, including beaded lirae and microscopic striae, are consistently described across these sources. The species appears in the Biodiversity Heritage Library, the World Register of Marine Species, and Gastropods.com, reflecting its established place in taxonomic and ecological literature. Its significance lies in being a well-documented, endemic Australian trochid with a characteristic shell morphology that has been repeatedly studied and cataloged over more than a century.
Did You Know?
- The shell size of Clanculus plebejus varies between 6 mm and 11 mm.
- Its shell is pinkish brown, gray, or yellow, with ribs articulated with dots of black and white.
- The species is endemic to Australia, occurring off New South Wales, South Australia, Tasmania, Victoria, and Western Australia.
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