Amastra turritella

Amastra turritella
Shell of Amastra turritella (specimen at the Natural History Museum, Rotterdam)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Stylommatophora
Family:	Amastridae
Genus:	Amastra
Species:	A. turritella
Binomial name
Amastra turritella (A. Férussac, 1821)
Location of Oʻahu
Synonyms
Achatina oahuensisGreen, 1827 junior subjective synonym Achatinella inornataMighels, 1845 junior subjective synonym Amastra (Paramastra) turritella(A. Férussac, 1821) alternative representation Helix (Cochlogena) turritellaA. Férussac, 1821 superseded combination Helix turritellaA. Férussac, 1821 superseded combination Paramastra turritella(A. Férussac, 1821) superseded combination

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

Subspecies

• Amastra turritella aieaHyatt & Pilsbry, 1911
• Amastra turritella turritella(A. Férussac, 1821)
• Amastra turritella waiawaHyatt & Pilsbry, 1911

Description

The length of the shell can reach 20 mm, its diameter 8.7 mm

The shell is dextral, elongate, and conic with fine striations. It consists of six whorls, ending in an obtuse apex. The suture is distinct and simple, not duplicated.

The aperture is prominently oblong, with the peristome thickened on the interior margin. The columella is nearly straight, perforate, and features a well-defined rib, adding to its structural detail.

The typical form, as illustrated by Ferussac, is characterized by a chestnut-brown coloration. The embryonic shell often appears darker with a purplish hue, although it can also present as whitish-corneous or flesh-colored. The apex is relatively blunt and rounded, with the second embryonic whorl displaying very fine vertical striae, occasionally interrupted by weak spiral lines.

In the adult stage, the shell surface is marked with fine striae overlaying low growth wrinkles. The subsutural region is usually a paler shade, providing a subtle contrast. The aperture is blue-white internally, sometimes exhibiting a faint pink tint. The outer lip is sharp, while the columellar plica is moderately strong, occasionally accompanied by a subtle, oblique fold positioned above it. The axis is generally perforate, completing the distinctive features of the shell.

The animal is compact, measuring only half the length of the shell. It is predominantly dark slate-colored along the sides, with the superior portion and tentacles a deep black. The underside of the foot is light gray, while the mantle is a rich dark brown, adding a subtle contrast to its overall appearance. ^[2]

Distribution

This species is endemic to Hawai, occurring on Oʻahu.

References

1. Amastra turritella (A. Férussac, 1821) . 29 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. 205. Retrieved 3 December 2024. 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. pp. 1–248.

External links

• Férussac, A. E. J. P. F. d'Audebard de (1821–1822). Tableaux systématiques des animaux mollusques classés en familles naturelles, dans lesquels on a établi la concordance de tous les systèmes; suivis d'un Prodrome général pour tous les mollusques ou fluviatiles, vivantes ou fossiles. Paris.
• Mighels, J.W. (1845). "Descriptions of shells from the Sandwich Islands, and other localities". Proceedings of the Boston Society of Natural History. 2: 21.
• Green, J. (1827). "Description of two new species of the genus Achatina, from the Sandwich Islands - with some remarks on the Ti, the plant on which these snails are commonly found". Contributions of the Maclurian Lyceum to the Arts and Sciences. 1 (2): 49.