Oospira smithi
Encyclopedia
Oospira smithi is a species
of air-breathing land snail
, a terrestrial
gastropod mollusk in the family Clausiliidae
, the door snails.
This land snail lives in limestone areas in Vietnam
. The original description was published in 2007, and included details of the reproductive system and the radula
. The shell is sinistral in coiling and has 8 or 9 whorls
.
The specific name smithi is in honor of Mr. Jady Smith, the project manager of the field research that resulted in the discovery of this species.
The type locality is Cat Ba Island
, near the entrance of the Trung Trang Cave, 6.iv.2001, 20°47.38'N 106°59.87'E, Haiphong
Province, Vietnam. All other known localities are also on Cat Ba Island
.
is sinistral, not decollate, rather large, fusiform, solid, dark-brown, not translucent. Apical whorls
are relatively broad. With 8-9 whorls, changing from apically moderately convex to somewhat flattened. Apical whorls are very finely, spirally punctated, the remaining ones with very fine, regular striae. The striae are rather faint above the aperture
and not coarser on the neck. Suture is slightly indented. Neck is without a crest. Peristome is continuous, whitish, broadly reflexed and detached; basic margin more or less semicircular.
Peristome is double; inner lip recognizable as a narrow ridge, contacting the body whorl
and closing the umbilicus (visible in not fully grown specimens); outer lip is protruding, forming a small, free tube. Aperture
is pear-shaped, whitish inside, with a sinulus which is not defined at the palatal side. Lamella parietalis (= superior) very prominent, reaching the margin of the peristome, which is conspicuously curved at that site; its inner end merging into the lamella spiralis. Inside the shell, the lamella columellaris reaches somewhat further than ventrally, whereas both the lamella subcolumellaris and the spiralis are slightly shorter; without a lamella inserta. In frontal view, the lamella columellaris is visible as a low, nearly straight lamella, not reaching the margin of the peristome, whereas the lamella subcolumellaris reaches the margin of the peristome in most specimens. With six plicae palatales: plica principalis, shortly visible in frontal view, ventro-laterally accompanied by five short, somewhat curved plicae, increasingly diverging from the principalis and nearly running parallel which each other, so that the lowest one runs most obliquely. Inside the body whorl, the plicae are connected by a lunella-like ridge of callus. Clausilial
blade is simple, ending with a sharp angle.
The width of the shell is 5.0 (8 whorls)-5.7 mm (9 whorls), on average 5.4 mm. The height of the shell is 18.6 mm (8 whorls)-22.3 mm (9 whorls), on average 20.5 mm.
Among the species in the subgenus Atractophaedusa, this species is most similar to the recently described Oospira antibouddah Nordsieck, 2003. The other consubgeneric species, viz. Oospira kebavica (von Moellendorff, 1901), Oospira pyknosoma Gittenberger & Vermeulen, 2001, and Oospira rhopaloides (von Moellendorff, 1901), all have decollated shells when fully grown. Oospira smithi differs from Oospira antibouddah (of which a population was discovered at Vietnam, Quang Ninh Prov., Ha Long Bay area, unnamed island in Dau Moi Temper area, 13.ix.2003, 20°55.69'N 107°09.40'E – so far this species was only known from its type locality “Vietnam, Tonkin, 4 km from Cam Pha”) by the more slender shell, with a clearly visible lamella subcolumellaris, and by the shorter plicae palatales.
Reproductive system
: Vagina is short to very short. Oviduct is measuring about 2/3 of the length of the proximal part of the pedunculus, which is clearly shorter than its much narrower distal segment. Proximal part of the pedunculus about as broad as the proximal half of the oviduct, which is twice as broad as the distal half; the much narrower diverticulum reaches somewhat further than the bursa of the bursa copulatrix, which is separate from the spermoviduct. Male part of the genitalia forming a loop because the vas deferens and a short, most proximal part of the penis are united by a common sheath; with a single retractor muscle, inserting rather close to the beginning of the vas deferens, without a flagellum or caecum. The luminal structure, as far as visible in the transparent genital slides, enables the distinction of three segments: (1) a short broadest part with a relatively simple, longitudinal, luminal structure, (2) a much longer part, with a more complicated luminal surface of many protuberances that very gradually decrease in size towards segment (3), which has a wall structure with very small, irregular protuberances and changes into the epiphallus near the insertion site of the retractor muscle, without an obvious boundary.
Radula
: The large main cusp of the central tooth is accompanied by very small ectocones. The 7-8 adjoining lateral teeth in half a row have equally small ectocones. All these teeth have prominent basal plates with interrow support ridges. In the first marginal tooth, the main cusp is less symmetrical and the basal plate is less prominently developed. The following 12 (at least) marginal teeth are increasingly more asymmetrical initially, with an endocone, which increases in prominence towards the radular margin, whereas the ectones remain unicuspid or bicuspid at most.
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 lives in limestone 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 original description was published in 2007, and included details of the reproductive system and 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...
. The shell is sinistral in coiling and has 8 or 9 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...
.
The specific name smithi is in honor of Mr. Jady Smith, the project manager of the field research that resulted in the discovery of this species.
Distribution
This species occurs in:The type locality is Cat Ba Island
Cat Ba Island
Cat Ba is the largest of the 366 islands spanning 260km2 that comprise the Cat Ba Archipelago, which makes up the southeastern edge of Ha Long Bay in Northern Vietnam. Cat Ba island has a surface area of 285 km2 and maintains the dramatic and rugged features of Ha Long Bay...
, near the entrance of the Trung Trang Cave, 6.iv.2001, 20°47.38'N 106°59.87'E, Haiphong
Haiphong
, also Haiphong, is the third most populous city in Vietnam. The name means, "coastal defence".-History:Hai Phong was originally founded by Lê Chân, the female general of a Vietnamese revolution against the Chinese led by the Trưng Sisters in the year 43 C.E.The area which is now known as Duong...
Province, Vietnam. All other known localities are also on Cat Ba Island
Cat Ba Island
Cat Ba is the largest of the 366 islands spanning 260km2 that comprise the Cat Ba Archipelago, which makes up the southeastern edge of Ha Long Bay in Northern Vietnam. Cat Ba island has a surface area of 285 km2 and maintains the dramatic and rugged features of Ha Long Bay...
.
Description
The shellGastropod 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 sinistral, not decollate, rather large, fusiform, solid, dark-brown, not translucent. Apical 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...
are relatively broad. With 8-9 whorls, changing from apically moderately convex to somewhat flattened. Apical whorls are very finely, spirally punctated, the remaining ones with very fine, regular striae. The striae are rather faint above 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....
and not coarser on the neck. Suture is slightly indented. Neck is without a crest. Peristome is continuous, whitish, broadly reflexed and detached; basic margin more or less semicircular.
Peristome is double; inner lip recognizable as a narrow ridge, contacting the body 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...
and closing the umbilicus (visible in not fully grown specimens); outer lip is protruding, forming a small, free tube. 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 pear-shaped, whitish inside, with a sinulus which is not defined at the palatal side. Lamella parietalis (= superior) very prominent, reaching the margin of the peristome, which is conspicuously curved at that site; its inner end merging into the lamella spiralis. Inside the shell, the lamella columellaris reaches somewhat further than ventrally, whereas both the lamella subcolumellaris and the spiralis are slightly shorter; without a lamella inserta. In frontal view, the lamella columellaris is visible as a low, nearly straight lamella, not reaching the margin of the peristome, whereas the lamella subcolumellaris reaches the margin of the peristome in most specimens. With six plicae palatales: plica principalis, shortly visible in frontal view, ventro-laterally accompanied by five short, somewhat curved plicae, increasingly diverging from the principalis and nearly running parallel which each other, so that the lowest one runs most obliquely. Inside the body whorl, the plicae are connected by a lunella-like ridge of callus. Clausilial
Clausilium
The clausilium is a calcareous anatomical structure which is found in one group of air-breathing land snails: terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails...
blade is simple, ending with a sharp angle.
The width of the shell is 5.0 (8 whorls)-5.7 mm (9 whorls), on average 5.4 mm. The height of the shell is 18.6 mm (8 whorls)-22.3 mm (9 whorls), on average 20.5 mm.
Among the species in the subgenus Atractophaedusa, this species is most similar to the recently described Oospira antibouddah Nordsieck, 2003. The other consubgeneric species, viz. Oospira kebavica (von Moellendorff, 1901), Oospira pyknosoma Gittenberger & Vermeulen, 2001, and Oospira rhopaloides (von Moellendorff, 1901), all have decollated shells when fully grown. Oospira smithi differs from Oospira antibouddah (of which a population was discovered at Vietnam, Quang Ninh Prov., Ha Long Bay area, unnamed island in Dau Moi Temper area, 13.ix.2003, 20°55.69'N 107°09.40'E – so far this species was only known from its type locality “Vietnam, Tonkin, 4 km from Cam Pha”) by the more slender shell, with a clearly visible lamella subcolumellaris, and by the shorter plicae palatales.
Reproductive system
Reproductive system of gastropods
The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals...
: Vagina is short to very short. Oviduct is measuring about 2/3 of the length of the proximal part of the pedunculus, which is clearly shorter than its much narrower distal segment. Proximal part of the pedunculus about as broad as the proximal half of the oviduct, which is twice as broad as the distal half; the much narrower diverticulum reaches somewhat further than the bursa of the bursa copulatrix, which is separate from the spermoviduct. Male part of the genitalia forming a loop because the vas deferens and a short, most proximal part of the penis are united by a common sheath; with a single retractor muscle, inserting rather close to the beginning of the vas deferens, without a flagellum or caecum. The luminal structure, as far as visible in the transparent genital slides, enables the distinction of three segments: (1) a short broadest part with a relatively simple, longitudinal, luminal structure, (2) a much longer part, with a more complicated luminal surface of many protuberances that very gradually decrease in size towards segment (3), which has a wall structure with very small, irregular protuberances and changes into the epiphallus near the insertion site of the retractor muscle, without an obvious boundary.
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...
: The large main cusp of the central tooth is accompanied by very small ectocones. The 7-8 adjoining lateral teeth in half a row have equally small ectocones. All these teeth have prominent basal plates with interrow support ridges. In the first marginal tooth, the main cusp is less symmetrical and the basal plate is less prominently developed. The following 12 (at least) marginal teeth are increasingly more asymmetrical initially, with an endocone, which increases in prominence towards the radular margin, whereas the ectones remain unicuspid or bicuspid at most.