Oospira duci
Encyclopedia
Oospira duci is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of air-breathing land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...

, a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 gastropod mollusk in the family Clausiliidae
Clausiliidae
Clausiliidae, common name door snails, are a taxonomic family of small, very elongate, mostly left-handed, air-breathing land snails, sinistral terrestrial pulmonate gastropod mollusks....

, the door snails.

This land snail, which was described in 2007, lives in limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 areas in Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

. The species was described from just one shell, and thus no details of the anatomy of the soft parts or the radula could be provided. The shell is decollate (which means that the several of the earlier whorls have been shed and the shell sealed off anew, making the spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

 blunt-ended.

The specific name duci is in honor of the biologist Le Thien Duc.

Distribution

This species occurs in:

The type locality is Pu Luong Nature Reserve
Pu Luong Nature Reserve
Pù Luông Nature Reserve is a nature reserve in northern Vietnam. This nature reserve is situated in Quan Hoa and Ba Thuoc districts of Thanh Hoa Province, North Central Coast region of Vietnam. Pu Luong Nature Reserve is bordered by Mai Chau, Tan Lac and Lac Son districts of Hoa Binh Province...

, on a limestone hill near the small native village Am, 20°27.39'N 105°13.65'E, Thanh Hoa Province, Vietnam.

Description

The shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is dextral, decollate, rather large, more or less fusiform, solid, dark brown, not translucent. Apical whorls are not known. The decollated shell consists of five somewhat flattened whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

, separated by a slightly indented suture and increasing gradually in width. It is sculptured
Sculpture (mollusc)
The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...

 with distinct, regularly arranged ribs (5-8 per mm on the whorl above the aperture), somewhat fading above the aperture and hardly coarser in the cervical region. Neck is without a crest. Aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is detached, obliquely pear-shaped, whitish inside. Peristome is continuous, whitish, thickened and broadly reflexed; basal side more or less semicircular.

Lamella parietalis (= superior) is connected with the spiralis, rather prominent, reaching the margin of the peristome, which forms an obtuse angle at that site. In frontal view, the lamella columellaris (= inferior) is visible over a relatively long distance as a low, straight lamella ascending into the shell. Lamella subcolumellaris equally well visible in frontal view. Left laterally with six plicae palatales: plica principalis rather short, not visible in frontal view, at the end with five short, slightly curved plicae, somewhat diverging from the principalis and running parallel which each other. Since the single shell that was available has not been opened, details on the inside endings of the lamellae cannot be given.

The width of the shell is 7.0 mm. The height of the shell is 21.5 mm.

Oospira miranda Loosjes & Loosjes-van Bemmel, 1973, is the conchologically most similar species. However, the shell of Oospira miranda is light corneous, more or less smooth, i.e. with only some faint, irregular striae. Its topwhorls increase more rapidly in width, which gives the shell a more fusiform shape, and the lamella subcolumellaris is not visible in a frontal view.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK