''Margarites costalis'',

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

the boreal rosy margarite or the northern ridged margarite, 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 ...

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 ...

Margaritidae Margaritidae is a family of small sea snails, marine gastropod mollusks in the superfamily Trochoidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Bouchet, P. (2012). Margaritidae. Accessed through: World Register ...

. ;Subspecies: * ''Margarites costalis baxteri'' J. H. McLean, 1995 * ''Margarites costalis costalis'' (Gould, 1841)

Description

The size of the shell varies between 5 mm and 25 mm. It is a conical, grayish (sometimes with rose or creamy tint), deeply umbilicate shell with five evenly rounded

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 floral ...

s. The sculpture shows strong, distant, spiral ridges, crossed by 10 to 12 fine, raised axial threads. The thin, finely crenulate outer

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 sharp. The pearly rose

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 round. (Original description by W.H. Dall of the synonym ''Margarites (Pupillaria) rudis'') The shell is of moderate size. It is white with a pale olivaceous periostracum. The smooth nucleus consists of about one

and five subsequent whorls. The spiral

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

consists of two strong cords with wider interspaces and a thud on which the suture is laid and which forms the margin of the base. There is also a small thread between the suture and the posterior cord and on the body whorl a similar thread in the interspaces. On the base there are six or seven smaller closer cords separated by obscurely channeled interspaces between the verge of a narrow umbilicus and the basal margin. The axial sculpture consists of (on the penultimate whorl about 20) retractive riblets extending from suture to periphery, with wider interspaces, slightly nodulous at the intersections with the spiral cords. There are also close obvious incremental regular lines over the whole surface. The simple, rounded aperture is quadrate. There is a glaze on the body. The inner

is slightly thickened. The operculum is multispiral.Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 (1920)
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Distribution

This marine species occurs in circum-arctic waters; from

Labrador , nickname = "The Big Land" , etymology = , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 ...

, Canada and

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

Cape Cod Cape Cod is a peninsula extending into the Atlantic Ocean from the southeastern corner of mainland Massachusetts, in the northeastern United States. Its historic, maritime character and ample beaches attract heavy tourism during the summer mont ...

, USA; from the Bering Strait to Southern

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

References

* Broderip, W. J. and G. B. Sowerby. 1829. ''Observations on new or interesting Mollusca contained, for the most part, in the museum of the Zoological Society.'' Zoological Journal 4: 359–379, pl. 9 * Couthouy, J. P. 1838. ''Descriptions of new species of Mollusca and shells, and remarks on several polypi found in Massachusetts Bay''. Boston Journal of Natural History 2: 53–111, pls. 1–3. * Möller, H. P. C. 1842. ''Index molluscorum Groenlandiae''. Naturhistorisk Tidsskrift 4: 76–97. * Kiener, L. C. 1848. ''Genre Turbo. (Turbo, Lin.). Spécies Général et Iconographie des Coquilles Vivantes'' 10: pls. 1–16, 16 is36 * Middendorff, A. T. von. 1849. ''Beiträge zu einer Malacozoologia Rossica. II. Aufzählung und Beschreibung der zur Meeresfauna Russlands gehörigen einschaler.'' Mémoires de l'Académie Impériale des Sciences de Saint-Pétersbourg, Sciences Naturelles (6)6: 329–516, pls. 1–11. * Mörch, O. A. L. 1857. ''Fortegnelse over Gro/nlands Blo/ddyr. Gro/nland Geographisk og Statistisk Beskrevet 2: 75–100'' Commission hos Universitetsboghandler: Kjo/benhavn. *Dautzenberg, P. and H. Fischer. 1912. ''Mollusques provenant des campagnes de l'Hirondelle et de la Princess-Alice dans les Mers du Nord''. Résultats des Campagnes Scientifiques du Prince de Monaco 37: 631 pp., 2 maps, 11 plates * Abbott, R.T. (1974). ''American Seashells''. 2nd ed. Van Nostrand Reinhold: New York, NY (USA). 663 pp * Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification''. Collection Patrimoines Naturels, 50: pp. 180–213 * Kantor Yu.I. & Sysoev A.V. (2006) ''Marine and brackish water Gastropoda of Russia and adjacent countries: an illustrated catalogue''. Moscow: KMK Scientific Press. 372 pp. + 140 pls. page(s): 32 * Gulbin V.V. & Chaban E.M. (2012) ''Annotated list of shell-bearing gastropods of Commander Islands. Part I.'' The Bulletin of the Russian Far East Malacological Society 15–16: 5–30.

External links

* {{DEFAULTSORT:Margarites Costalis costalis Gastropods described in 1841