Perrierina insulana
| Perrierina insulana | |
|---|---|
| Holotype from the Auckland War Memorial Museum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Superfamily: | Cyamioidea |
| Family: | Cyamiidae |
| Genus: | Perrierina |
| Species: | P. insulana
|
| Binomial name | |
| Perrierina insulana A. W. B. Powell, 1933
| |
| Synonyms[1] | |
| |
Perrierina insulana is a species of sea snail, a marine gastropod mollusc in the family Cyamiidae.[2] It is endemic to New Zealand, found in the waters surrounding the Chatham Islands and Stewart Island.
Description
In the original description, Powell described the species as follows:
Shell minute, thin and fragile, ovate, equivalve and inequilateral. Beaks fairly prominent, with a moderately large rounded prodissoconch which is marked off from the post-embryonic part of the shell by a slightly raised thin rim. Sculpture of exceedingly fine and closely spaced concentric growth striae. Under a low power lens the surface appears to be smooth and glossy. Hinge plate narrow and long, typical. Right valve with two divergent cardinals, which are situated in front of the narrow oblique resilium. In addition there are four anterior and five posterior lamellae set obliquely on the distal parts of the hinge-plate. Left valve with three anterior cardinals, and the corresponding lamellae. Central cardinal rectangular, outer two narrow and slightly divergent. Valve margins smooth except for a few weak crenulations on the posterior section of the ventral edge. Colour creamy buff tinged with light brown towards the beaks. The hinge plate and provisions are stained reddish-brown, and there is a faint open pattern of a few zigzag lines, in light brown over the whole shell.[3]
The shells of the species measure 1.6 mm (0.063 in) in height, 1.9 mm (0.075 in) in width, and a single valve has a thickness of 0.4 mm (0.016 in).[4][3] It can be distinguished from P. ovata due to its more evenly ovate outline, and because the posterior of P. ovata is more broadly rounded and slightly subangled.[3]
Taxonomy
The species was first described by A. W. B. Powell in 1933.[3] The holotype was collected by Powell himself in February 1933, from shell sand at a depth of 18 m (59 ft) off the coast of Owenga Beach in the Chatham Islands, and is held by the Auckland War Memorial Museum.[5][6] The species is closely aligned with the fossil species P. ovata,[7] and Powell in 1933 believed that P. insulana was a decedent species of P. ovata.[3]
Distribution and habitat
P. insulana is endemic to New Zealand,[1] found in the waters of the Chatham Islands and Stewart Island at depths of between 0–55 m (0–180 ft).[4][8] Previously, the species was thought to be endemic to the Chatham Islands.[9]
Gallery
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Holotype underside
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Holotype
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Holotype underside
References
- ^ a b Spencer, H. G.; Marshall, B. A.; Willan, R. C. (June 2009). "Checklist of New Zealand living Mollusca". New Zealand Inventory of Biodiversity. Volume 1. Kingdom Animalia Radiata, Lopotrochozoa, Deuteromstomia. 1: 196–219. Wikidata Q125720861.
- ^ Perrierina insulana A. W. B. Powell, 1933. Retrieved through: World Register of Marine Species on 25 February 2026.
- ^ a b c d e 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. This article incorporates text from this source, which is under a CC BY 4.0 license.
- ^ a b "Perrierina insulana Powell, 1933". New Zealand Mollusca. Retrieved 25 February 2026.
- ^ 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.
- ^ "Perrierina insulana". Collections Online. Auckland War Memorial Museum. Retrieved 25 February 2026.
- ^ Powell, A.W.B. (1979). New Zealand Mollusca: Marine, Land and Freshwater Shells. Auckland: Collins. p. 401. ISBN 0002169061.
- ^ "bivalve, Perrierina insulana Powell, 1933 (Species)". Collections Online. Te Papa. Retrieved 25 February 2026.
- ^ Dell, R. K.; Edmonds, S. J. (1961). "Biological results of the Chatham Islands 1954 Expedition. Part 4. Marine Mollusca; Sipunculoidea" (PDF). New Zealand Oceanographic Institute Memoir. 7: 1–27. ISSN 0083-7903. Wikidata Q66412133.