''Calthalotia arruensis'' 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 ...

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 ...

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 ...

.Marshall, B. (2013). Calthalotia arruensis (Watson, 1880). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=719239 on 2014-01-08

Description

The strong, opaque shell has a conical shape. It is carinated and flat on the base. It is covered with tubercles, and colored with gray and pink. Its

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 ...

shows eight spiral rows of small round tubercles on each

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 ...

. The tubercles on the first two rows, are larger than the others; these, as well as the next three rows, are parted by distinct depressions. The lowest three rows are much closer together, but project a little, especially the center and largest row of the three. On the base there are about nine less strongly tuberculated spiral threads with feebler threads between. These intermediate threads become feebler towards the center. The tubercles are smooth and polished, but the whole intervening surface is sharply fretted with fine oblique puckerings. The color of the shell is white, beautifully flecked above with grayish-purple patches, and closely spotted with purplish-pink on the base. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

is high and sharp pointed. Its concavely conical slope is slightly broken at the sutures by the projection of the two superior rows of tubercles. It contains about ten flat whorls that increase very regularly in size. The suture is slight, but distinct, being defined by the slight carinal spiral above, and the double row of large tubercles below. 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 rather small, square, and very oblique. The outer lip is sharp but strong. The inner lip is strengthened internally by a buttress of porcelaneous nacre, which ends abruptly towards the point of the columella, forming a tooth. The columella, beveled off to a sharp edge, is pressed back on the umbilicus, which it completely closes, leaving only a central depression and a post-columellar furrow. The operculum is thin, yellow, and normal.Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
(described as ''Calliostoma arruense'')

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

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

References

* Watson, R.B. 1880. ''Mollusca of "H.M.S. Challenger" expedition. Part V. Families Solenoconchia, Trochidae, Heterophrosynidae, Litorinidae, Cerithiidae''. Journal of the Linnean Society of London, Zoology 15: 87-126 * Trochus (Thalotia) torresi Smith, E.A. 1884. ''Report on the zoological collections made in the Indo–Pacific Ocean during the voyage of the 'Alert', 1881–1882. Part 1.'' The collections from Melanesia. Mollusca: 34–508, 657–659, pls IV–XLIV. British Museum * Hedley, C. 1908. ''Studies on Australian Mollusca. Part 10.'' Proceedings of the Linnean Society of New South Wales 33: 456-489 * Ludbrook, N.H. 1941. ''Gastropoda from the Abattoirs Bore, Adelaide, South Australia, together with a list of some miscellaneous fossils from the bore''. Transactions of the Royal Society of South Australia 65: 79-102 * Wilson B. (1993) ''Australian marine shells. Prosobranch gastropods. Vol. 1''. Odyssey Publishing, Kallaroo, Western Australia, 408 pp.

External links

To World Register of Marine Species
{{Taxonbar, from=Q13450853 arruensis Gastropods of Australia Gastropods described in 1880