''Austrocochlea diminuta'' 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 ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.Bouchet, P. (2012). ''Austrocochlea diminuta'' (Hedley, 1912). Accessed through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=546940 on 2012-11-23

Description

(Original description by

Charles Hedley Charles Hedley (27 February 1862 – 14 September 1926) was a naturalist, specifically a malacologist. He was born in Britain, but he spent most of his life in Australia. He was the winner of the 1925 Clarke Medal. Early life Hedley was born ...

) The height of the shell attains 7 mm, its diameter also 7 mm. The small, solid shell has an ovate-turbinate shape. It is dull and rough. The 5½

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 are separated by impressed sutures. The colour of the shell is very variable: entire maroon or entire slate or either with broad radiating stripes of buff, or the spiials articulated with buff on a maroon or slate ground, or combinations of these. The nacre of the interior of 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 bordered with emerald.

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 ...

: the shell contains elevated spiral ridges, four or five on the upper whorls, about sixteen on the last, andsmaller and closer on the base. Both ridges and interstices are obliquely crossed by fine growth striae. The aperture is subquadrate, brilliantly nacreous with a narrow border. The base of 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 externally expanded, internally bearing three small tubercles. The throat contains about seven entering ridges which commence at the bevel within the

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 ...

. 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 a slight smear of callus. Hedley, C. 1912. Descriptions of some new or noteworthy shells in the Australian Museum. Records of the Australian Museum 8: 131-160
(described as ''Monodonta diminuta'')

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 Australia and occurs off

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

and

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

References

* Adams, A. 1853. ''Contributions towards a monograph of the Trochidae, a family of gastropodous Mollusca''. Proceedings of the Zoological Society of London 1851(19): 150-192 * Hedley, C. 1913. ''Studies of Australian Mollusca. Part XI''. Proceedings of the Linnean Society of New South Wales 38: 258-339 * Hedley, C. 1918. ''Narrative of an expedition of exploration in North Western Australia by Herbert Basedow. Special Report. Mollusca.'' Transactions of the Royal Geographical Society of Australasia, South Australian Branch 18: 263-283

External links

Barcode of Life (1 barcode)

Encyclopedia of Life

GenBank (5 nucleotides; 2 proteins)

World Register of Marine Species
{{Taxonbar, from=Q4825614 diminuta Gastropods of Australia Gastropods described in 1912