''Euchelus mysticus'', common name the mysticus 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 ...

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

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 ...

Chilodontaidae Chilodontaidae is a taxonomic family of mostly small deepwater sea snails, marine gastropod molluscs in the clade Vetigastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Taxonomy The family was previously in ...

.Bouchet, P. (2014). Euchelus mysticus Pilsbry, 1889. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=559705 on 2015-02-19

Description

The height of the globose-depressed shell attains 7 mm. Its color is yellowish-white, with purple-brown dots on the spiral ribs. The conic

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 very short and imperforate. The 4½ or 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). In nature File:Photograph and axial plane floral diagra ...

s increase very rapidly in size. The nuclear whorl is smooth, the remainder clathrate with strong spiral ribs crossed by elevated, close, vertical striae, which crenulate the ribs and cut the interstices into pits. There are 3 stronger spirals on the penultimate whorl, with a riblet in each interval. On the earlier whorls there are only 3 spirals. 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 ...

at its termination has about 27 spirals. The base if the shell has about 8, alternating in size. There is a strong spiral bordering the closed

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

. The large, quite oblique

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 ...

is expanded, slightly sulcate inside. The simple

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

is concave flattened, and above reflexed. It is connected with the upper margin of the peristome by a short shining parietal callus.Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
(described as ''Euchelus mysticus'')

Distribution

This species occurs in the Southwest Pacific.

References

External links

Encyclopedia of Life

World Register of Marine Species
{{Taxonbar, from=Q13614353 mysticus Gastropods described in 1889