Alcithoe wilsonae
| Alcithoe wilsonae | |
|---|---|
| Holotype from the Auckland War Memorial Museum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Neogastropoda |
| Family: | Volutidae |
| Genus: | Alcithoe |
| Species: | A. wilsonae
|
| Binomial name | |
| Alcithoe wilsonae (A. W. B. Powell, 1933)
| |
| Synonyms[1] | |
| |
Alcithoe wilsonae is a species of sea snail, a marine gastropod mollusc in the family Volutidae, the volutes.[1] A highly morphologically varied species, it endemic to New Zealand, found on the Chatham Rise, off the coast of the eastern South Island, and on a section of the Campbell Plateau between the South Island and the Auckland Islands.
Description
In the original description, Powell described the species as follows:
Shell large, solid, fusiform. Spire half height of aperture. Nucleus damaged. Post-embryonic whorls 5, spire whorls sub-angled at the middle, body-whorl moderately inflated, contracting gradually to a feeble fasciole. Sculpture consisting of narrow axial ribs, extending from suture to suture on the spire whorls, and to just below the periphery on the body-whorl. These axials are thickened slightly in the middle, where they cross the subangle. On the last half-whorl they become sub-obsolete. There are 14 axials on the penultimate whorl and 12 on the ante-penultimate. Aperture elongate, with a moderately wide but very shallow basal notch. Columella straight, with four strong oblique plaits, upper-most strongest, lower three becoming weaker in descending order. Inner-lip spread as a thin glaze in one wide sweep over the body-whorl. Colour pinkish-buff, maculated with three zones of irregular zigzag markings of dark reddish-brown. Upper band below suture, middle band at periphery, and lower one bordering the fasciole.[2]
The holotype of the species measures 109 mm (4.3 in) in height (112 mm (4.4 in) estimated undamaged height) and 47 mm (1.9 in) in diameter.[2] The species has four strong pillar plaits.[3] It is a highly morphologically variable species.[4]
Taxonomy
A. wilsonae was first described by A.W.B. Powell in 1933, using the name Pachymelon (Palomelon) wilsonae.[2] The holotype was collected from Owenga Beach in the Chatham Islands by Miss B. M. Wilson in 1933.[5][6] In 1978, Richard Dell synonymised Pachymelon with the genus Alcithoe, recombining the species as Alcithoe wilsonae. In the same paper, Dell synonymised Pachymelon (Palomelon) grahami and Pachymelon (Palomelon) smithi with Alcithoe wilsonae.[7] In 2011, A. knoxi was synonymised with A. wilsonae.[8]
The species likely diverged from other members of Alcithoe between 4.6 and 13.1 million years ago.[8]
Distribution and habitat
The species is endemic to New Zealand, found in the waters of the Chatham Rise, the eastern South Island and a section of the Campbell Plateau between the South Island and the Auckland Islands.[9] The fossil record extends back to the Tongaporutuan stage of the Cenozoic Era (between 10,920,000 and 6,500,000 years ago).[4]
Gallery
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Reverse view of holotype
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Type specimen (holotype of Alcithoe wilsonae acuminata)
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Type specimen (holotype of Pachymelon (Palomelon) grahami)
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Type specimen (holotype of Pachymelon (Palomelon) smithi)
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Shell found near the Auckland Islands
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Shell found off the coast of eastern Otago
References
- ^ a b Alcithoe wilsonae (A. W. B. Powell, 1933). 4 December 2025. Retrieved through: World Register of Marine Species.
- ^ a b c Powell, A. W. B. (1933). "The Marine Mollusca of the Chatham Islands". Records of the Auckland Institute and Museum. 1: 181–208. ISSN 0067-0464. JSTOR 42905950. Wikidata Q58676558.
- ^ Powell, A.W.B. (1979). New Zealand Mollusca: Marine, Land and Freshwater Shells. Auckland: Collins. pp. 209–210. ISBN 0002169061.
- ^ a b Hills, Simon Francis Kahu (2010), Evolution in a marine gastropod : rocks, clocks, DNA and diversity, Massey Research Online, hdl:10179/1628, Wikidata Q112158836
- ^ Blom, Wilma M. (2025). "Annotated Catalogue of Fossil and Extant Molluscan Types in the Auckland War Memorial Museum". Bulletin of the Auckland Museum. 22. doi:10.32912/BULLETIN/22. ISSN 1176-3213. OCLC 1550165130. Wikidata Q135397912.
- ^ "Alcithoe wilsonae". Collections Online. Auckland War Memorial Museum. Retrieved 4 December 2025.
- ^ Dell, R.K. (1978). "Additions to the New Zealand Recent molluscan fauna with notes on Pachymelon (Palomelon)". National Museum of New Zealand Records. 1 (11).
- ^ a b Hills, Simon F. K.; Trewick, Steven A.; Morgan-Richards, Mary (6 October 2011). "Phylogenetic information of genes, illustrated with mitochondrial data from a genus of gastropod molluscs". Biological Journal of the Linnean Society. 104 (4): 770–785. doi:10.1111/J.1095-8312.2011.01756.X. ISSN 0024-4066. Wikidata Q60902816.
- ^ "Alcithoe wilsonae (Powell, 1933)". New Zealand Mollusca. Retrieved 4 December 2025.
Further reading
- Bail, P.; Limpus, A. (2005). "The Recent Volutes of New Zealand, with a revision of the genus Alcithoe H. & A. Adams, 1853". A Conchological Iconography 11. Hackenheim, Germany: ConchBooks.