''Trochus stellatus'', common name the stellate trochus, 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.Australian Faunal Directory: Trochus stellatus
The species is now extinct. '' Trochus incrassatus'' Lamarck, 1822 is considered a synonym of this species by the

Australian Faunal Directory The Australian Faunal Directory is an online catalogue of taxonomic and biological information on all animal species known to occur within Australia. It is a database produced by the Department of Climate Change, Energy, the Environment and Water ...

Description

The size of this large, heavy, top-shaped shell varies between 18 mm and 40 mm. The shell has wrinkled plaits and

concatenated In formal language theory and computer programming, string concatenation is the operation of joining character strings end-to-end. For example, the concatenation of "snow" and "ball" is "snowball". In certain formalizations of concatenatio ...

dots. The sutures of the upper

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 spinous and radiated. The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

has a yellow tint to it and has brown stripes. The inside of the shell is a glossy white. (Description as ''Trochus incrassatus'') The height of the shell attains 30 mm, its diameter also 30 mm. The, thick, heavy, solid shell has a conical shape. It is, whitish, radiately striped above and below with purplish red. The outlines of 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. Spire ...

are convex. The 7 to 8 whorls are coarsely granulose in about 5 or 6 spiral series, of which the upper series is most prominent. The periphery is rounded. The base of the shell is a little concave, with about 7 concentric granulose or subgranulose lirae. 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 strongly lirate within upon the parietal and outer wall. The basal margin contains four or five teeth. 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 dentate. The umbilical tract is nearly smooth or obsoletely spirally plicate.H. Pilsbry, Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution

This marine species occurs off

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

, the

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Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

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, and Australia (the

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 ...

); also in the Indian Ocean off

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References

* Gmelin, J.F. & Linnaeus, C. 1791. ''Caroli a Linné Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentis, synonymis, locis.'' Editio decima tertia aucta, reformata. Lipsiae : G.E. Beer. * Röding, P.F. 1798. ''Museum Boltenianum sive Catalogus cimeliorum e tribus regnis naturae quae olim collegerat Joa''. Hamburg : Trappii 199 pp. * Lamarck, J.B. 1822. ''Histoire naturelle des Animaux sans Vertèbres''. Paris : J.B. Lamarck Vol. 7 711 pp. * Hedley, C. 1899. ''The Mollusca of Funafuti. Part 1. Gastropoda''. Memoirs of the Australian Museum 3(7): 395–488, 49 text figs * Schepman, M.M. 1908. ''Prosobranchia (excluding Heteropoda and parasitic Prosobranchia). Rhipidoglossa and Docoglossa. With an appendix by Prof. R. Bergh ectinobranchiata'' Siboga-Expéditie Report 49(1): 1–108, 9 pls * Dautzenberg, Ph. (1929). ''Contribution à l'étude de la faune de Madagascar: Mollusca marina testacea''. Faune des colonies françaises, III (fasc. 4). Société d'Editions géographiques, maritimes et coloniales: Paris. 321–636, plates IV-VII pp * Winckworth, R. 1936. ''Marine mollusca from South India and Ceylon IV - X.'' Proceedings of the Malacological Society of London 22(1): 16-22 * Satyamurti, S.T. 1952. ''Mollusca of Krusadai Is. I. Amphineura and Gastropoda''. Bulletin of the Madras Government Museum, Natural History ns 1(no. 2, pt 6): 267 pp., 34 pls * Ladd, H.S. 1966. ''Chitons and gastropods (Haliotidae through Adeorbidae) from the western Pacific Islands''. United States Geological Survey Professional Papers 531: 1-98 16 pls * Hinton, A. 1972. ''Shells of New Guinea and the Central Indo-Pacific''. Milton : Jacaranda Press xviii 94 pp * Rajagopal, A.S. & Mookherjee, H.P. 1978. ''Contributions to the molluscan fauna of India. Pt. I. Marine molluscs of the Coromandel Coast, Palk Strait and Gulf of Mannar - Gastropoda: Archaeogastropoda''. Records of the Zoological Survey of India 12: 1-48 * Short, J.W. & Potter, D.G. 1987. ''Shells of Queensland and The Great Barrier Reef.'' Drummoyne, NSW : Golden press Pty Ltd 135 pp., 60 pl. * Wilson, B. 1993. ''Australian Marine Shells. Prosobranch Gastropods''. Kallaroo, Western Australia : Odyssey Publishing Vol. 1 408 pp. * Sasaki, T. (2000) ''Family Trochidae''. In: Okutani, T. (ed.), Marine Mollusks in Japan. Tokai University Press, Tokyo, 55-83 (in Japanese)

External links

*
Great Barrier Reef Invertebrates: ''Trochus stellatus''

Atlas of Living Australia: ''Trochus stellaris''
stellatus Gastropods described in 1791 Taxa named by Johann Friedrich Gmelin {{Trochidae-stub