''Bathybembix aeola'', common name the changing margarite, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 ...

.Bouchet, P. (2012). ''Bathybembix aeola'' (Watson, 1879). Retrieved through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=512081 on 2013-04-14

Description

The size of the shell varies between 40 mm and 50 mm. (Original description by Watson) The high shell is concavely conical. It is carinated, sculptured on the upper

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). In nature File:Photograph and axial plane floral diagra ...

s, and smooth or wrinkled below. It is thin, with a tumid lirated base. It is narrowly umbilicated, with a smooth epidermis, thin, but especially so on the base. The shell is more or less nacreous all over under a thin porcellanous upper layer. Sculpture: The first three whorls (after the embryonic

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

) are reticulated by three sharp remote spirals, and rather stronger, slightly oblique longitudinals, which rise at their intersection into small sharp pyramidal tubercles. The interstices are a little broader than high. This system gradually dies out and leaves the surface smooth, only the row of infrasutural tubercles survives in an enlarged but depressed form. And springing from these some sinuous oblique and slightly irregular longitudinal puckerings appear on the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

, which is nearly bisected by the sharpish, slightly expressed, finely tubercled carina. This bisection of the body whorl arises from the great prolongation and tumidity of the base On this base, below the carina, are five narrow, equally parted, spiral threads, and two intra-umbilical ones, which are more contiguous. Besides this larger system of sculpture, the whole surface is covered with minute, oblique, irregular, and interrupted puckerings of the epidermis. Colour: Theshell has a brownish yellow colour, but below the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...

there is a thin pure white porcellanous layer, through which and the epidermis the sheen of the nacreous layer gleams. The base is whiter, the epidermis there being very thin. Inside, the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

shows an exquisite roseate nacre. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

is high, with a slightly concave contour, the lines of which are hardly swollen out by the slight tumidity of the body whorl. The apex is eroded, but evidently small. The shell contains 7 or 8 whorls, of regular increase, quite flat, except the last, which is very slightly constricted below the suture, a very little tumid on the upper slope, sharply carinated but not much angulated at the suture, and very tumid on the base. The suture is linear, strongly defined above by the square furrow lying between the lines of tubercles which marginate the suture above and below. On the body whorl it becomes slightly pouting, from the projection of the carina and the slight infrasutural constriction. The nearly square aperture is very little oblique in the line of its advance, but standing out a little obliquely to the axis of the shell. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

is thin, not descending. The columellar lip is thin, spread out broadly at its base over the umbilicus, which it largely conceals, with a deep narrow furrow behind it. It advances thin and pointed, curving over to the right to its angular junction with the basal lip. The umbilicus is defined by a spiral thread and with two other spirals within it. It is not so much small as concealed by the columellar lip. Watson R. B. (1878-1883). Mollusca of H. M. S. Challenger Expedition. Journal of the Linnean Society of London
(described as ''Bembix aeola'')

Distribution

This marine species occurs off

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and East

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

References

External links

Biodiversity Heritage Library (6 publications)

Encyclopedia of Life

World Register of Marine Species
* {{Taxonbar, from=Q13436288 aeola Gastropods described in 1879