Amastra Lahainana
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''Amastra lahainana'' 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 air-breathing
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 family
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 ...
.


Description

The length of the shell attains 11 mm, its diameter 6 mm. (Original description) The shell is perforate or closed, ovate-conic, thin but relatively robust, with a matte surface. It features coarse growth striae near the suture, which are weaker elsewhere. The coloration is highly variable, ranging from carob brown, russet, apricot buff, and ochraceous buff to nearly white. Occasionally, the shell exhibits a bipartite color pattern, such as a light upper portion with a dark base or a light base with a dark spire; more rarely, it is dark with a light base. In some cases, a thin, fragmentary outer cuticle may be present, ivory-yellow with zigzag or net-like markings in mummy brown. The shell contains 5½
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 embryonic whorls are more convex and finely costulate than in ''
Amastra affinis ''Amastra affinis'' is a species of land snail, a terrestrial pulmonate gastropod mollusc in the family Amastridae. ;Subspecies: * ''Amastra affinis kaupakaluana'' Hyatt & Pilsbry, 1911 (taxon inquirendum) * ''Amastra affinis pupoidea'' (Newcomb ...
'', with the embryonic shell displaying colors such as chestnut brown, pinkish buff, or cream, often marked with oblique corneous streaks on the last half whorl. 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 ...
closely resembles that of ''A. affinis'', with the outer
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 ...
only slightly thickened internally. The columellar fold is strong and prominent.


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 ...
to Hawaii and occurs on
Maui Maui (; Hawaiian language, Hawaiian: ) is the second largest island in the Hawaiian archipelago, at 727.2 square miles (1,883 km2). It is the List of islands of the United States by area, 17th-largest in the United States. Maui is one of ...
Island.


References

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External links


ANSP Malacology Collection : image
{{Taxonbar, from=Q131362304 lahainana Gastropods described in 1914