''Alycaeus gibbosulus'' 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), ...

of small

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

s with a

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

and an operculum,

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

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 ...

s in the family

Alycaeidae Alycaeidae is a taxonomic family of small to large tropical land snails with an operculum, terrestrial gastropod mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). ...

Description

The length of the shell attains 10 mm., its diameter 7 mm. (Original description in Latin) The shell is turreted with a pronounced gibbosity and is narrowly umbilicated. It has a reddish-violet hue, with 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 ...

becoming paler and yellowish, while the

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

is whitish. The five

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 are highly convex and joined by a deep, simple suture. The first whorl is smooth, while the next three are densely covered with fine transverse ribs and spiral striations. The body whorl is inflated and more distinctly ribbed. Near 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 ...

, it is briefly but strongly constricted, slightly smooth, barely deflected, and fitted with a thin tube about two to three millimeters long, which is sometimes almost fully immersed. The aperture is circular and moderately wide, surrounded by a simple, slightly expanded margin in young specimens, and bilabiate in adults. The inner

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

extends outward, forming a tubiform, thickened structure, while the outer lip is dilated and thin. The operculum is solid, with a slightly convex, horny inner surface, submammillate at the center, and multi-spiral, featuring a transverse oval and eccentric muscular impression. The outer surface is calcareous, slightly concave, and irregularly wrinkled. Characteristics: The

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called " ...

shows oblique striae. The broad central tooth of the

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

contains five cusps with the central cusp blunt. This species is presumably closely related to

Alycaeus conformis ''Alycaeus conformis'' is a species of small land snails with a gill and an operculum, terrestrial gastropod mollusks in the family Alycaeidae. Description The length of the shell attains 10 mm, its diameter 8.5 mm. (Original description) The ...

, due to the similarity in the protoconch sculpture. The ovarium of the living specimen is wide with pointed anterior and blunt posterior end. The

bursa copulatrix Bursa () is a city in northwestern Turkey and the administrative center of Bursa Province. The list of cities in Turkey, fourth-most populous city in Turkey and List of largest cities and towns in Turkey, second-most populous in the Marmara Regio ...

large, extends beyond ovarium posteriorly, opens at middle part of ovarium near its base, bursa has a thickened posterior portion. The

seminal receptacle Female sperm storage is a biological process and often a type of sexual selection in which sperm cells transferred to a female during mating are temporarily retained within a specific part of the reproductive tract before the oocyte, or egg, is fe ...

is small and oval.

Distribution

This species occurs in

Peninsular Malaysia Peninsular Malaysia, historically known as Malaya and also known as West Malaysia or the Malaysian Peninsula, is the western part of Malaysia that comprises the southern part of the Malay Peninsula on Mainland Southeast Asia and the list of isla ...

References

External links

* * {{Taxonbar, from=Q106808300 gibbosulus Gastropods described in 1872