''Nepotilla aculeata'' is a species of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk in the family

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". '' Malacologia'' 47(1-2). . 3 ...

Description

The length of the shell attains 3 mm, its diameter 1.8 mm (Original description) The small, yellowish brown shell is broadly fusiform, It contains five

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

s, including a prominent two-whorled

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

, which is finely spirally lirate. The adult whorls are strongly angled about the upper third by a prominent spiral keel, which bears at regular intervals well developed spinose nodules, about 10 on the

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

. Above to the suture the whorl is concavely hollowed, with a finely nodulous keel. Below the carina are two prominent keels, bearing numerous sharp nodules, connected somewhat irregularly above and below, with axial riblets. On the base are about seven keels, the first two slightly nodose, the rest smooth. The three prominent keels give the whorls a square appearance. The aperture is rather expanded. The

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

is short and open. The columella is concave, corrugated by the basal keels, which pass into the shell. The outer lip is armed by four spines, alternating large and small. The sinus is sutural, deep and narrow, bounded on one side by the sutural lirae, and on the other by the finely a nodulous keel. May, W.L. 1915 [1916
''Additions to the Tasmanian Mollusca, with descriptions of new species.'' Papers and Proceedings of the Royal Society of Tasmania 1915: 75-99">916">May, W.L. 1915 [1916
''Additions to the Tasmanian Mollusca, with descriptions of new species.'' Papers and Proceedings of the Royal Society of Tasmania 1915: 75-99/ref>

Distribution

This marine species is endemic to Australia and occurs off Tasmania.

References

* Powell, A.W.B. 1966. ''The molluscan families Speightiidae and Turridae, an evaluation of the valid taxa, both Recent and fossil, with list of characteristic species''. Bulletin of the Auckland Institute and Museum. Auckland, New Zealand 5: 1–184, pls 1–23

External links

Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213-359, pls 42-56

Atlas of Living Australia: ''Nepotilla aculeata''
* {{DEFAULTSORT:Nepotilla Aculeata aculeata Gastropods described in 1916 Gastropods of Australia