''Pleurotomella 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" ...

.MolluscaBase (2019). Pleurotomella aculeata (Webster, 1906). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=599025 on 2019-02-03

Description

The length of the shell attains 6 mm, its diameter 3.3 mm. (Original description) The shell is buff-coloured, lighter towards the

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

and

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 ...

. 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 reticulated

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 " ...

of 1¼ whorl. The

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

: Longitudinally and slightly diagonally ribbed, the ribs crossed by two strong spiral keels. The ribs and keels are about equal in strength, the intersections forming sharp points. 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 ...

has upon the base four additional keels, the space between the two peripheral keels and the four on the base being greater than that between any other two. A fine thread is visible in this wide space, there is also a duplication of the posterior keel. The body whorl has about twelve ribs. The sutures of the early whorls are sharp, those of the latter are concavely round. 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 ...

descends vertically from the body whorl. The siphonal canal, which is straight, has about eight faint striations. The space between the suture and the first spiral keel contains the anal fasciole. Under magnification one can see faint radial striations between the keels, also the reticulation of the protoconch. The sinus of the type is so little damaged that to draw it perfect can scarcely be called reconstruction.Webster, W.H. (1906) ''Results of dredging on the continental shelf of New Zealand''. Transactions and Proceedings of the New Zealand Institute, 38, 305–316, pl. 38
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Distribution

This marine species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to New Zealand and occurs off Northland

References

* Powell, A.W.B. 1979 ''New Zealand Mollusca: Marine, Land and Freshwater Shells'', Collins, Auckland

External links

Spencer H.G., Willan R.C., Marshall B.A. & Murray T.J. (2011). Checklist of the Recent Mollusca Recorded from the New Zealand Exclusive Economic Zone
*
Beu, A.G. 2011 ''Marine Molluscs of oxygen isotope stages of the last 2 million years in New Zealand. Part 4. Gastropoda (Ptenoglossa, Neogastropoda, Heterobranchia)''. Journal of the Royal Society of New Zealand 41, 1–153
{{DEFAULTSORT:Pleurotomella 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 1906 Gastropods of New Zealand