''Microdrillia niponica'' is a species of

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 ...

Borsoniidae Borsoniidae is a monophyletic family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet, P. (2011). Borsoniidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/ ...

.WoRMS (2015). Microdrillia niponica (E. A. Smith, 1879). In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://marinespecies.org/aphia.php/aphia.php?p=taxdetails&id=434404 on 2016-03-16

Description

The length of the shell attains 7 mm; its width 2 mm.. (Original description) The shell has a shortly fusiform shape and is light brown. It contains 6 ½

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. The nucleus consists of 1½ rather large, globose, glassy shining whorls. The four whorls following are strongly keeled around the middle, concave above, with two or three fine spiral lirae, and also concave below the carina, margined at the upper and lower boundaries by a fine thread-like lira arcuately or flexuously elevately striated above the carina, and obliquely but in an opposite direction, beneath it. 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 ...

is encircled beneath the principal keel by about ten lirae, whereof the uppermost is the stoutest, the rest gradually becoming finer towards the base. The interstices between them crossed by elevated striae or lines of increment. 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 ...

is small, brownish, occupying about three-sevenths of the entire length of the shell. Its slit is situated in the concavity above the principal carination. The

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 a little convex or prominent in the middle, and oblique below it. The

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water i ...

is short and scarcely recurved.Smith, Edgar A. "11. On a Collection of Mollusca from Japan." Proceedings of the Zoological Society of London. Vol. 47. No. 1. Blackwell Publishing Ltd, 1879.
(described as ''Pleurotoma difficilis'')

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 ...

References

External links

Bouchet P., Kantor Yu.I., Sysoev A. & Puillandre N. (2011) A new operational classification of the Conoidea. Journal of Molluscan Studies 77: 273–308
* {{DEFAULTSORT:Microdrillia Niponica niponica Gastropods described in 1879