Clanculus guineensis
A marine gastropod with a solid, striped shell from West African waters.
Clanculus guineensis is a marine snail belonging to the Trochidae family, commonly known as top snails. Its shell is very solid, conical in shape, and somewhat flattened, with a noticeable angle at the periphery and a deep umbilicus. The shell is whitish, decorated on top with broad, radiating purplish brown stripes, while the base features narrower radiating stripes or a checkered pattern in the same color. The shell has about six whorls that are flat or slightly concave above; the whitish apex is eroded, and the later whorls are spirally beaded. The body whorl dips slightly forward and has about seven beaded spiral ridges on its upper surface, with fine oblique striations in between. The base is nearly flat, with seven or eight concentric beaded ridges. The rounded aperture is rhomboidal, with thick outer and basal lips that are evenly and finely pleated inside. The columella is oblique, deeply set, and noticeably grooved near its insertion, with a toothed edge near the base that curves smoothly into the basal margin. The parietal wall has a white, wrinkled callus, and its umbilical edge is toothed. The wide umbilicus is deep and barely narrows as it goes inward, bordered by a strong, sharply toothed rib. Unlike typical members of the genus *Clanculus*, this species lacks a strong tooth at the base of the columella. The shell size ranges from 15 mm to 25 mm. This species is found in the Atlantic Ocean off the coasts of Angola, the Ivory Coast, and Gabon.
Quick Facts
- Taxon
- Clanculus guineensis
Facts from the source article.
Lore & Background
The shell of Clanculus guineensis is very solid and conical, rather depressed, angulate at the periphery, and deeply umbilicate. Its color is whitish, painted with broad radiating purplish brown stripes above, while the base shows narrow radiating stripes or tessellations of the same shade. The shell has about six whorls that are planulate or slightly concave above, with a whitish eroded apex. The succeeding whorls are spirally beaded, and the body whorl slightly descends anteriorly, bearing on its upper surface about seven spiral beaded lirae with obliquely finely striate interstices. The base is subplanulate, concentrically sculptured with about seven or eight beaded lirae. The rounded aperture is rhomboidal, with thick outer and basal lips that are evenly and finely plicate within. The columella is oblique, deeply entering, conspicuously fielded near its insertion, with a denticulate edge near the base that passes into the basal margin with a regular curve. The parietal wall bears a white wrinkled callus, the umbilical margin of which is dentate. The wide umbilicus is deep, scarcely narrowed as it penetrates, bordered by a strong acutely dentate rib. This species differs from the typical forms of Clanculus in lacking the strong tooth at the base of the columella.
Reader's Guide
Clanculus guineensis is a species of sea snail in the family Trochidae, documented from the Atlantic Ocean off Angola, the Ivory Coast, and Gabon. Its shell size ranges from 15 mm to 25 mm, and its distinctive coloration—broad purplish brown stripes on a whitish background—along with its deeply umbilicate base and beaded spiral sculpture, make it recognizable among top snails. The species is notable for its departure from typical Clanculus morphology: it lacks the strong tooth at the base of the columella that characterizes many other members of the genus. This anatomical difference is a key diagnostic feature. The shell's solid construction, conical shape, and detailed sculptural elements—such as the about seven spiral beaded lirae on the body whorl and the about seven or eight concentric beaded lirae on the base—are described in the source article. The umbilicus is wide and deep, bordered by a strong acutely dentate rib, and the aperture is rhomboidal with thick, plicate lips. The species is known only from the cited distribution and the reference work by Gofas, Afonso, and Brandão on the shells and molluscs of Angola.
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