Amastra obesa
| Amastra obesa | |
|---|---|
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| Amastra obesa shell | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Stylommatophora |
| Family: | Amastridae |
| Genus: | Amastra |
| Species: | A. obesa
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| Binomial name | |
| Amastra obesa | |
| Synonyms | |
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Amastra obesa is a species of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Amastridae. [2]
- Subspecies
- Amastra obesa aurora Pilsbry & C. M. Cooke, 1914
- Amastra obesa obesa (Newcomb, 1853)
Description
[edit]The length of the shell attains 13 mm, its diameter 9.5 mm.
The shell is dextral, depressed-conical, and inflated, with a solid structure and pronounced striations. It is covered by a dark umber-colored epidermis. It is composed of five rounded whorls. The apex is acute, and the suture is simple yet distinctly defined.
The aperture is ovate and white, with the columella featuring a strong, prominent white plait. The outer lip is simple and slightly thickened on the inner side.
The shell is imperforate or faintly rimate, globose with a short, concavely conic spire, and relatively thin. It is pale brown beneath a dull chestnut or umber cuticle, which remains intact except near the aperture. The whorls of the protoconch, numbering about 2½, are convex and finely striated, with the last one being subtly angular and slightly perforate.
The subsequent whorls exhibit coarse, irregular wrinkles, with the body whorl rounded at the periphery and faintly adorned with shallow, coarse spiral striations. The aperture is small and oblique, white on the interior. The outer lip features a narrow internal rib. The columella is short, white, and adorned with an obtuse lamella.
The entire animal is a sooty black. The upper tentacles are prominently clubbed, while the lower tentacles have light-colored tips. The surface granulations are large and pronounced. The tentacles are longer than the shell. Its movements are notably slow and cautious, exuding a timid demeanor.[3]
Distribution
[edit]This species is endemic to Hawai, occurring on Molokai island.
References
[edit]- ^ "WoRMS - World Register of Marine Species - Amastra elongata (Newcomb, 1853)". www.marinespecies.org. Retrieved 2024-11-19.
- ^ Amastra obesa (Newcomb, 1853). 25 December 2024. Retrieved through: World Register of Marine Species.
- ^ 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. 268. Retrieved 2 December 2024.
{{cite book}}: CS1 maint: multiple names: authors list (link)
This article incorporates text from this source, which is in the public domain.
- 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)
External links
[edit]- Newcomb, W. (1853). "Descriptions of new species of Achatinella from Sandwich Islands". Annals of the Lyceum of Natural History of New York. 6: 26.
