''Aesopus australis'' 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 ...

Columbellidae The Columbellidae, the dove snails or dove shells, are a family of minute to small sea snails, marine gastropod mollusks in the order Neogastropoda.Bouchet, P.; Gofas, S. (2010). Columbellidae. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) Wo ...

, the dove snails.

Description

(Original description) The shell is elongate and fusiform, moderately solid, and pale brown with a shining surface. It consists of 7½

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, with the two apical whorls being thin and papillose. The remaining whorls feature somewhat distant, flat longitudinal plications on the upper portion, crossed by fine impressed lines. The middle of 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 ...

is smooth, with a few impressed lines near the base. The sutures are grooved. 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 narrowly ovate and dilated below. The outer lip is arcuate and slightly thickened within. The columella is somewhat flattened, covered with a smooth, white callus, and is abruptly truncate at the base.G.F. Angas (1877), Description of one genus and twenty-five species of marine shells from New South Wales; Proceedings of the Zoological Society of London 1877

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 ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and occurs off New South Wales, South Australia and Victoria.

References

* Verco, J.C. 1910. Notes on South Australian marine Mollusca with descriptions of new species. Part XIII. Transactions of the Royal Society of South Australia 34: 115–145 * Hedley, C. 1913. Studies of Australian Mollusca. Part XI. Proceedings of the Linnean Society of New South Wales 38: 258–339 * Iredale, T. & McMichael, D.F. 1962. A reference list of the marine Mollusca of New South Wales. Memoirs of the Australian Museum 11: 1–109 * Wilson, B. 1994. Australian marine shells. Prosobranch gastropods. Kallaroo, WA : Odyssey Publishing Vol. 2 370 pp. {{Taxonbar, from=Q13231395 australis Gastropods described in 1877 Gastropods of Australia