Macrochlamys indica
Encyclopedia
Macrochlamys indica 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...

 pulmonate gastropod mollusk in the family Ariophantidae
Ariophantidae
Ariophantidae is a taxonomic family of air-breathing land snails and semi-slugs, terrestrial pulmonate gastropod mollusks in the superfamily Helicarionoidea .- Distribution :...

.

Distribution

This species occurs in countries including:

This species has not yet become established in the USA, but it is considered to represent a potentially serious threat as a pest, an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

 which could negatively effect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine
Quarantine
Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. The word comes from the Italian quarantena, meaning forty-day period....

 significance in the USA.

Shell 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 perforate, depressed, smooth, polished throughout, translucent, pale brownish tawny, not distinctly striated, but with microscopic longitudinal impressed lines, slightly flexuous and not close together. 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...

 is low, conoid. The suture is slightly impressed. The shell has 5.5 whorls, that are slightly convex above. The last whorl
Body whorl
Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...

 is not descending. The last whorl is rounded at the periphery and moderately convex beneath.

The 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 slightly oblique and broadly lunate. The peristome is thin in one plane, with columellar margin is curved, oblique, never quite vertical, carried forward and briefly reflected above.

The width of the shell is 16-18.5 mm. The height of the shell is 8.5 mm.

Anatomy

The animal is purplish grey not black, elongate. The right shell-lobe is small, the left is narrowly reflected over the edge of the peristome, and at the basal side gives off a short tongue-like process. The right dorsal lobe is narrow and elongate, the left in two distinct portions.

In the genitalia is a moderately long cylindrical blunt kalc-sac is given off at the junction of the vas deferens, and the caecum of the penis, to which the retractor muscle is attached, is sharply coiled. The dart-sac is long, the spermatheca short and elongately pearshaped.

The radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...

contains about 88 rows of teeth, with the arrangement: 34.2.9.1.9.2.34 (45.1.45).

Further reading

  • El-Alfy N. Z., Al-Ali K. A. & Abdel-Rahim A. H. 1994. Karotype, meiosis and sperm formation in the land snail Macrochlamys indica. Qatar University Science Journal 14(1), 122–128.
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