Biology:Amastra sinistrorsa

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Short description: Species of mollusc


Amastra sinistrorsa
Shell of Amastra sinistrorsa
Scientific classification edit
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Order: Stylommatophora
Family: Amastridae
Genus: Amastra
Species:
A. sinistrorsa
Binomial name
Amastra sinistrorsa
Baldwin, 1906
Synonyms

Amastra (Heteramastra) sinistrorsa Baldwin, 1896 alternative representation

Amastra sinistrorsa 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 14.7 mm, its diameter 6.2 mm

The shell contains 6½ whorls. It is imperforate, sinistral, and lanceolate and has a relatively thin structure. The spire is elongated, featuring straight outlines. The first half-whorl is smooth and convex, forming an obtuse apex. The following whorl is flattened and subacutely carinate near the base, adorned with fine, curved riblets. On subsequent whorls, the carina diminishes and eventually disappears, while the riblets become finer and more closely spaced. The later whorls are moderately convex, displaying rather coarse growth wrinkles and lacking angularity above the impressed suture.

The aperture is strongly oblique, with a thin outer lip. The columella is straight, its edge narrowly reflexed and adnate above, bearing a small, very oblique fold. [2]

Distribution

This species is endemic to Hawaii, occurring on the main island at Hamakua.

References

  1. Amastra sinistrorsaBaldwin, 1906. 7 December 2024. Retrieved through: World Register of Marine Species.
  2. 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. 240. https://www.biodiversitylibrary.org/page/23701752. Retrieved 3 December 2024.  This article incorporates text from a publication now in the public domain:


Wikidata ☰ Q131429689 entry