''Lischkeia imperialis'', common name : the giant imperial 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 ...

Eucyclidae Eucyclidae is a family of gastropods in the superfamily Seguenzioidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This family has no subfamilies. Genera Genera within the family Eucyclidae include: * '' Amberley ...

Description

The shell grows to a length of 60 mm. The extremely thin, white shell has globosely a conical shape with five (?)

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 umbilicus is reduced to a mere chink under the thin callus of the upper part of the columellar lip. 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 opt ...

is rounded rectangular. The columella is somewhat concave. The margins are all thin. The base of the shell is flattened convex, with seven revolving ribs, the outermost of which is just within the periphery. They are crossed by radiating lines of growth, regular and very fine, but raised into low, very sharp lamellae which pass over the periphery onto the upper surface of the whorl. The

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

is provided with two strong revolving ribs, one of which forms the periphery, while the other lies a little less than half wav from the first toward the oblique, round suture. The outer lip is sharp but strong. It is porcelaneous on the edge, brilliantly nacreous within. It descends very slightly. The white, columellar lip is thick and bent nearly to the point of the columella over the umbilicus. It would be reverted but for the great thickness of the spiral pad, which comes twining up behind it out of the umbilicus, and out of which, at the point of the columella, it forms a flat, triangular, tooth-like expansion. The umbilicus consists of a minute spiral hole, which twists in between the overlying columellar lip and the umbilical pad. The edge is corrugated with the old lines of the lip.Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
(described as ''Turcicula imperialis'')

Distribution

This species is distributed in the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

, the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

and the

Lesser Antilles The Lesser Antilles ( es, link=no, Antillas Menores; french: link=no, Petites Antilles; pap, Antias Menor; nl, Kleine Antillen) are a group of islands in the Caribbean Sea. Most of them are part of a long, partially volcanic island arc betwe ...

Offshore West coast Barbados, this species has come to light via freshly-dead 'crabbed' examples found in traps set around 600 ft. depth

References

* Rosenberg, G., F. Moretzsohn, and E. F. García. 2009. ''Gastropoda (Mollusca) of the Gulf of Mexico'', pp. 579–699 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas.

External links

* {{DEFAULTSORT:Lischkeia imperialis imperialis Gastropods described in 1881