''Trochus stellatus'', common name the stellate trochus, 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 ...

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 ''Trochus stellatus'', common name the stellate trochus, is a species of sea snail, a marine gastropod mollusk in the family (biology), family Trochidae, the top snails.

'' Lamarck, 1822 is considered a synonym of this species by the

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

Description

The size of this large, heavy, top-shaped shell varies between 18 mm and 40 mm. The shell has wrinkled plaits and concatenated 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). Whorls in nature File:Photograph and axial plane floral ...

s are spinous and radiated. The shell 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. Spires are ...

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, 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 strongly lirate within upon the parietal and outer wall. The basal margin contains four or five teeth. The columella 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

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Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

, the

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Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

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New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

, and Australia (the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

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_ ...

and

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

); also in the Indian Ocean off

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

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 {{Trochidae-stub