''Gibbula capensis'' is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of sea snail, a marine gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.

Description

The size of the shell varies between 10 mm and 14 mm. The narrowly umbilicated shell has a conoid-depressed shape with 5

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane flo ...

s. The first whorl is roseate, eroded, the following convex above, depressed beneath, whitish or rosy, flammulated with brownish-violet radiating maculations, obliquely striate and spirally lirate. The lirae are flat, narrow and not granose. The body whorl is dilated, subangulate above, depresso-carinated at the periphery, convex beneath and ornamented with 9 concentric reddish lirae. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

is oblique and subquadrate. The

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

is simple. The

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...

is arcuate, denticulate at base, slightly calloused above, almost covering the

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy * ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus urbis Romae The ...

.Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution

This marine species occurs off the Western Cape, and Saldanha Bay to Cape Agulhas, Rep. South Africa

References

* Kilburn, R.N. & Rippey, E. (1982) ''Sea Shells of Southern Africa''. Macmillan South Africa, Johannesburg, xi + 249 pp. page(s): 40 {{DEFAULTSORT:Gibbula capensis capensis Gastropods described in 1791