''Amastra rubens'' 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), ...

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 ...

, a

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 ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

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 ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the

Amastridae Amastridae is a Taxonomy (biology), taxonomic family (biology), family of small, air-breathing, land snails, Terrestrial animal, terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea.MolluscaBase eds. (2021). MolluscaBase. Amast ...

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 ...

;Subspecies: * ''Amastra rubens castanea'' Hyatt & Pilsbry, 1911 * ''Amastra rubens corneiformis'' Hyatt & Pilsbry, 1911 * ''Amastra rubens infelix'' Hyatt & Pilsbry, 1911 * ''Amastra rubens kahana'' Hyatt & Pilsbry, 1911 * ''Amastra rubens rubens'' (A. Gould, 1845) * ''Amastra rubens rubinia'' Hyatt & Pilsbry, 1911

Description

The length of the shell attains 19 mm, its diameter 9.1 mm. The shell is elongate-ovate and robust, with a thick, straw-colored exterior. It is composed of 6⅓ whorls. 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 chestnut-toned, transitioning to a reddish hue at the anterior end. Comprising six convex

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 shell features an impressed suture and is sporadically covered with patches of brown epidermis. The ovate

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 bordered by a simple

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 ...

, thickened internally and tinged with a roseate hue, while the throat is white. The columellar fold is thin, and the shell is imperforate. Although plain in form, the shell is notably distinguished by its coloration, particularly the vibrant tones of the aperture. The first half-whorl of the shell is smooth, transitioning into extremely fine, sharp, closely spaced, and slightly arcuate longitudinal striae, which persist for the next two whorls. Following this, relatively coarse but low growth wrinkles begin to develop. The embryonic shell comprises nearly three whorls, characterized by a dark brown color, which appears purplish-brown when worn. Subsequent spire whorls exhibit coarse wrinkles beneath the suture, leaving the remainder of the whorls and the entirety of the body whorl nearly smooth. The upper four or five whorls are reddish-brown, while the final one or two whorls are pale red-brown or whitish. These are covered by a thin, glossy, yellowish or flesh-tinted inner cuticle, which in turn is often overlain by a brown outer layer (ranging from blackish-brown to olivaceous-brown). This outer layer is typically worn off ventrally and may remain well-preserved, exist in shreds, or be almost entirely absent. The interior of the basal and outer lips is typically rose-colored, though in some instances, it exhibits a bluish-white hue, adding a striking variation to the shell’s appearance. The animal is dark slate in color and approximately the same length as the shell. Its tentacles are black, while the underside of the foot and the mantle are brown. Highly timid by nature, it resides buried beneath leaves and other decaying vegetation, making it well-adapted to its concealed lifestyle.

Distribution

This species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, occurring on

Oahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

Island.

References

External links

*
Conchology.be: image
{{Taxonbar, from=Q306875 Molluscs of Hawaii

rubens Sir Peter Paul Rubens ( ; ; 28 June 1577 – 30 May 1640) was a Flemish artist and diplomat. He is considered the most influential artist of the Flemish Baroque tradition. Rubens' highly charged compositions reference erudite aspects of clas ...

Gastropods described in 1845