''Nepotilla aculeata'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Raphitomidae Raphitomidae is a Family (biology), family of small to medium-sized sea snails, marine (ocean), marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families" ...

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). In nature File:Photograph and axial plane floral diagra ...

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 (biology), morphology of the gastropod shell, 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 ...

. 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 In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

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 i ...

is short and open. The

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

is concave, corrugated by the basal keels, which pass into the shell. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

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 Aculeata is an infraorder of Hymenoptera containing ants, bees, and stinging wasps. The name is a reference to the defining feature of the group, which is the modification of the ovipositor into a stinger. However, many members of the group cann ...

Gastropods described in 1916 Gastropods of Australia