Amalda novaezelandiae

Amalda novaezelandiae
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Family:	Ancillariidae
Genus:	Amalda
Species:	A. novaezelandiae
Binomial name
Amalda novaezelandiae (Sowerby, 1859)
Synonyms
† Amalda (Gracilispira) firthiOlson, 1956 junior subjective synonym Amalda (Gracilispira) novaezelandiaeG. B. Sowerby II, 1859 superseded combination Ancilla (Anaulax) nanaR. B. Watson, 1886 junior subjective synonym Ancilla crystallinaBrookes, 1926 junior subjective synonym Ancilla nanaR.B. Watson, 1886 junior subjective synonym Ancillaria bicolor [sic] (misspelling and misapplication of tricolor Gray, 1847 by Suter, 1913) Ancillaria novaezelandiaeSowerby, 1859 † Baryspira (Gracilispira) firthiOlson, 1956 junior subjective synonym) Baryspira novaezelandiaeOlson, 1956 Baryspira novaezelandiae benthicola Dell, 1956

Amalda novaezelandiae is a species of small sea snail, a gastropod mollusc of the family Ancillariidae. ^[1]

Description

(Original description in Latin) The shell is small and white, resembling Amalda marginata but is more slender, with a smooth, pyramidal spire and a short aperture. Like Amalda lineata and Amalda oblonga , it differs from Amalda marginata in having no ridges on the spire; from Amalda lineata, which it otherwise most nearly resembles, in the shortness of the aperture. ^[2]

(Described as Ancilla (Anaulax) nana) Shell: Narrowly ovate and brown, adorned with whitish and darker bands. The spire is high and small, sharply pointed, with a concealed suture, a narrow aperture, and a prominent labial pad.

Sculpture: Longitudinals — faint growth lines are present. Spirals — the columella and the front of the shell are twisted, scored, and white, with a sharply defined upper edge. Above this, a brown band is bordered by a fine furrow, with another similar, sharper furrow slightly above, which extends into a small prickle on the outer lip. The upper portion of the body whorl is encased in enamel, banded with alternating white, brown, and pale tones. These bands continue up the spire, making it possible to count the whorls.

Color: Fawn, with white and brown bands. The spire is high and delicate, while the apex is small, bluntly rounded, and free from enamel.

Whorls: Six, with the last being slightly elongated and faintly swollen. The suture is concealed.

Aperture: Narrowly oval, pointed at the top, truncated, and notched at the front. The outer lip is gently curved, thin, and ends in a projecting point at the front edge. The inner lip is slightly convex along the body, concave below, with a thick labial pad that reinforces the twisted columella, fills the upper aperture, extends over the body, and covers the spire.

Operculum: Triangular-lanceolate, sharply pointed at the top with a terminal nucleus toward the outer edge. It is faintly lined, thin, yellow, and slightly glossy, and completely fills the shell’s aperture. ^[3]

Distribution

This marine species is endemic to New Zealand and occurs off North Island and northern part of South Island, and Chatham Rise. It also appears in the fossil record ^[4]

References

1. Amalda novaezelandiae (G.B. Sowerby II, 1859) . 10 November 2024. Retrieved through: World Register of Marine Species .
2. Sowerby, G.B. II (1859). Monograph of the genus Ancillaria. In: G. B. Sowerby II (ed.), Thesaurus Conchyliorum, or monographs of Genera of Shells, vol. 3 (19). privately published. pp. 57–67. This article incorporates text from this source, which is in the public domain .
3. Watson, R.B. (1886). "Report on the Scaphopoda and Gasteropoda collected by H.M.S. Challenger during the years 1873-76. Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873–76". Zoology. 15 (42): 230. This article incorporates text from this source, which is in the public domain .
4. Michaux, B. (1989). "Morphological variation of species through time". Biological Journal of the Linnean Society. 38 (3): 239–255. doi:10.1111/j.1095-8312.1989.tb01577.x. ISSN   0024-4066.

• Powell A W B, New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN   0-00-216906-1
• Olson, O.P. (1956). "The genus Baryspira (Mollusca) in New Zealand". New Zealand Geological Survey Paleontological Bulletin. 24: 1–32.
• Brookes, A.E. (1926). "New species of recent Mollusca". Transactions of the New Zealand Institute. 56: 589.
• Spencer, H.G., Marshall, B.A. & Willan, R.C. ( (2009). Checklist of New Zealand living Mollusca. Pp 196-219. in: Gordon, D.P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Christchurch: Canterbury University Press.