''Achatinella byronii'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 gastropod mollusks that have shells (those without shells are known as ...

, a terrestrial

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 includ ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family Achatinellidae. This species is

endemic Endemism is the state of a species being found 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 found elsew ...

Oahu Oahu () (Hawaiian language, Hawaiian: ''Oʻahu'' ()), also known as "The Gathering place#Island of Oʻahu as The Gathering Place, Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over t ...

, in the

Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...

. ''Achatinella byronii'' is the type species of the subgenus ''Bulimella''.

Shell description

The dextral or sinistral shell is imperforate and pyramidal-conic; solid and glossy with an obtuse apex. The shell has 6.5

whorls 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). Whorls in nature File:Photograph and axial plane floral d ...

. Shell color varies, but is typically green and light greenish-yellow in oblique streaks on the last two whorls, with a faint green peripheral band and a dark chestnut band bordering the suture below. The preceding whorl is yellow with a chestnut band and the three embryonic whorls are pinkish gray. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is white and the lip is bordered with dark brown. Faint spiral striae

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

the embryonic whorls, and later whorls are convex and irregularly wrinkled in the direction of growth-lines. The whorls are convex and the last is often very obtusely angular at the periphery. The aperture is strongly oblique and the lip thickened within by a strong rib near the margin. The columellar fold is moderate, and white or tinted. The height of the shell is 20.0 mm. The width of the shell is 11.0 mm.

References

This article incorporates public domain text (a

public domain The public domain (PD) consists of all the creative work A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...

work of the United States Government A work of the United States government, is defined by the United States copyright law, as "a work prepared by an officer or employee of the United States Government as part of that person's official duties." "A 'work of the United States Governmen ...

) from reference. U.S. Fish and Wildlife Service. (1992) Recovery Plan for the O’ahu Tree Snails of the Genus ''Achatinella''. U.S. Fish and Wildlife Service, Portland, Oregon, 64 pp. + 64 pp. of appendices + 5 figures
PDF
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External links

* https://web.archive.org/web/20090918160853/http://hbmp.hawaii.edu/hbmp/printpage.asp?spp=IMGASN7060 {{Taxonbar, from=Q3319348 byronii Molluscs of Hawaii Endemic fauna of Hawaii Critically endangered fauna of the United States Gastropods described in 1828 Taxa named by William Wood (zoologist) Taxonomy articles created by Polbot