''Margarella violacea'' is a

species In biology, a species is the basic unit of 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 the appropriate s ...

of small

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

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 e ...

in the

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

Calliostomatidae Calliostomatidae is a family of sea snails within the superfamily Trochoidea and the clade Vetigastropoda.Gofas, S. (2013). Calliostomatidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetail ...

, the top snails.Bouchet, P. (2010). ''Margarella whiteana'' Linse, 2002. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=197259 on 2022-10-24

Description

The animal is pale beige in color and has a pair of cephalic tentacles. The eyes are large and black. The shell is small and wider than it is high.Bouchet, P. (2010). ''Margarella whiteana'' Linse, 2002. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=197259 on 2022-10-24 The size of an adult shell varies between 7 mm and 13.5 mm, but can be up to 8.4 mm in height and 9.9 mm in diameter. The purplish-pink shell is imperforate, orbicular-conical, thin and smooth, and is covered in fine pink or dark pink spiral lines. There are four swollen

whorls 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 floral d ...

. The suture is scarcely impressed. The rounded-quadrangular

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 opt ...

is angular above, and subangular at the base of slightly thickened and arcuate columella. The umbilico-columellar tract is excavated.

Distribution

This species occurs in the Atlantic Ocean on the coast of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...

, i.e. in the Magellanic Region.

References

* Hombron, J. B. and H. Jacquinot. 1848. ''Voyage au Pôle Sud et dans l'Océanie''. Zoologie, Mollusques pls. 9, 11–12, 14, 16–17, 19, 21–25. Gide et J. Baudry: Paris. * Gould, A. A. 1852. ''Mollusca & Shells''. United States Exploring Expedition 12: xv + 510 pp. Gould & Lincoln: Boston. * Rochebrune, A.-T. and J. Mabille. 1885. ''Diagnoses de mollusques nouveaux, recueillis par les membres de la mission du Cap Horn et M. Lebrun'', Préparateur au Muséum, chargé d'une mission à Santa-Cruz de Patagonie. Bulletin de la Société Philomathique de Paris (7)9: 100-111 * Cooper, J. E. and H. B. Preston. 1910. ''Diagnoses of new species of marine and freshwater shells from the Falkland Islands, including descriptions of two new genera of marine Pelecypoda''. Annals and Magazine of Natural History (8)5: 110–114, pl. 4. * Preston, H. B. 1913. ''Descriptions of fifteen new species and varieties of marine shells from the Falkland Islands''. Annals and Magazine of Natural History (8)11: 218–223, pl. 4.

External links

King, P. P. and W. J. Broderip. 1832. ''Description of the Cirrhipeda, Conchifera and Mollusca, in a collection formed by the officers of H.M.S. Adventure and Beagle employed between the years 1826 and 1830 in surveying the southern coasts of South America''. Zoological Journal 5: 332–349

Zelaya D.G. (2004) The genus Margarella Thiele, 1893 (Gastropoda: Trochidae) in the southwestern Atlantic Ocean. The Nautilus 118(3): 112-120.
* {{DEFAULTSORT:Margarella Violacea violacea Gastropods described in 1832