Amastra nana

Amastra nana
	Shell of Amastra nana
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Stylommatophora
Family:	Amastridae
Genus:	Amastra
Species:	A. nana
Binomial name
	Amastra nana; (Baldwin, 1895)
Synonyms
	Achatinella (Amastra) nana Baldwin, 1895 superseded combination; Amastra (Amastra) nana (Baldwin, 1895) alternative representation;

Amastra nana is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Amastridae.^[1]

Description

The length of the shell attains 11.5 mm, its diameter 6.5 mm.

(Original description) The shell contains 6½ whorls. When fully extended in motion, the animal is as long as its shell. The mantle is light brown, while the foot is brown on both the upper and lower surfaces, with darker spots along the sides. The tentacles and the anterior portion of the head are nearly black, providing a striking contrast.^[2]

(Later supplemental description by Hyatt, A. & Pilsbry, H. A. ) The shell is rimate, ovate-conic, and thin, with an impure whitish or pale brown coloration. The apex is dark brown, and the surface, except near the aperture, is covered with a brown or olivaceous-brown cuticle adorned with light streaks or zigzag stripes.

The shell of the protoconch is distinctly costate and carinate, while the later whorls are sculpted with irregular wrinkle-like striations. The spire has nearly straight outlines, with the whorls being only slightly convex.

The aperture is relatively small, with the lip somewhat thickened on the interior. The columellar fold is sharp and well-defined.^[3]

Distribution

This species is endemic to Hawaii, occurring on Maui Island.

References

^ Amastra nana(Baldwin, 1895)1. 6 December 2024. Retrieved through: World Register of Marine Species.
^ Baldwin D.D. (1895). "Descriptions of new species of Achatinellidae from the Hawaiian Islands". Proceedings of the Academy of Natural Sciences of Philadelphia. 47: 232. This article incorporates text from this source, which is in the public domain.
^ Hyatt, A. & Pilsbry, H. A. (1910–1911). Manual of conchology, structural and systematic, with illustrations of the species. Ser. 2, Pulmonata. Vol. 21: Achatinellidae (Amastrinae). Philadelphia: Conchological Department, Academy of Natural Sciences. p. 301. Retrieved 3 December 2024.{{cite book}}: CS1 maint: multiple names: authors list (link) This article incorporates text from this source, which is in the public domain.

External links

Cowie, R. H., Evenhuis, N. L. & Christensen, C. C. (1995). Catalog of the native land and freshwater molluscs of the Hawaiian Islands. vi. Leiden: Backhuys Publishers. p. 107.{{cite book}}: CS1 maint: multiple names: authors list (link)

[WoRMS-1] Amastra nana(Baldwin, 1895)1. 6 December 2024. Retrieved through: World Register of Marine Species.

[2] Baldwin D.D. (1895). "Descriptions of new species of Achatinellidae from the Hawaiian Islands". Proceedings of the Academy of Natural Sciences of Philadelphia. 47: 232. This article incorporates text from this source, which is in the public domain.

[3] Hyatt, A. & Pilsbry, H. A. (1910–1911). Manual of conchology, structural and systematic, with illustrations of the species. Ser. 2, Pulmonata. Vol. 21: Achatinellidae (Amastrinae). Philadelphia: Conchological Department, Academy of Natural Sciences. p. 301. Retrieved 3 December 2024.{{cite book}}: CS1 maint: multiple names: authors list (link) This article incorporates text from this source, which is in the public domain.

[1]

[2]

[3]