''Pleurotomella aculeola'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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). . 39 ...

Description

The length of the shell attains 8.5 mm, its diameter 4 mm. (Original description) The small shell is lanceolate-fusiform. Its colour is buff, stained with ferruginous at the extremities. The shell contains eight

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, the first three minute, smooth, forming the

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 ...

, the rest sculptured, gradate and rapidly increasing in size.

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 ...

: broad peripheral undulations compose radial ribs spaced at ten to a whorl, fine spiral cords continue across both ribs and interstices and extend over the base. Of these, 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 ...

carries sixteen and the penultimate six, those on the periphery increase in size and sharpen the projection of the ribs. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is ovate,. The outer lip is thin, simple, with a slight smear of callus on the columella. 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, straight and open. Hedley, C. 1915. ''Studies on Australian Mollusca. Part XII.'' Proceedings of the Linnean Society of New South Wales 39: 695–755, pls 77–85

Distribution

This marine species is

endemic Endemism is the state of a species being found 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 found elsew ...

to Australia and occurs off

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

References

* Laseron, C. 1954. ''Revision of the New South Wales Turridae (Mollusca).'' Australian Zoological Handbook. Sydney : Royal Zoological Society of New South Wales pp. 56, pls 1–12. * 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 * 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

External links

* {{DEFAULTSORT:Pleurotomella Aculeola

aculeola The hooktooth dogfish, ''Aculeola nigra'', is a small, little-known dogfish, the only member of the genus ''Aculeola''. The type specimen is held at the National Natural History Museum, Santiago, Chile. Description The hooktooth dogfish has a ...

Gastropods described in 1915 Gastropods of Australia