''Clanculus thomasi'' 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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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.Bouchet, P. (2012). ''Clanculus thomasi'' (Crosse, 1862). 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 list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=547248 on 2012-11-23

Description

The size of the shell varies between 5 mm and 15 mm. The umbilicate shell has a conic-globose shape. It is maculate with white on a ground of reddish carmine. The five

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 convex. They are spirally traversed by five very finely granulose lirae, the first two small, third larger, fourth small, fifth larger than the others. The suture is profoundly impressed and canaliculate. 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 ...

contains 8 lirae on the base encircling the umbilicus. The columella is unequally bidentate. The basal tooth is larger and compressed. The lip at the base is obsoletely denticulate, elsewhere edentulous. The oblique

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 less ringent than most species of ''Clanculus''. The fauces (i.e. the part of the interior of a spiral shell that can be viewed by looking into the aperture) is sulcate and nacreous. The umbilicus is white, in young shells smooth, in adults obsoletely crenulated. A variety is olivaceous green, maculate with white, the apex rosy. It is a small species, with very prominent, compressed basal tooth, and slight crenulations at the margin of the umbilicus, the right lip not dentate.H. Pilsbry, Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
(described as ''Trochus thomasi'')

Distribution

This marine species occurs off

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

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland P ...

References

* Crosse, H. 1862. ''Descriptions d'espèces nouvelles de l'Archipel Calédonie''. Journal de Conchyliologie 10: 405-408 * Salisbury, A.E. 1936. ''Two new species of marine gastropods''. Proceedings of the Malacological Society of London 22(3): 124–125, pl. 13a * Iredale, T. 1938. ''Clanculus howinsulae'' Salisbury. Journal de Conchyliologie 21: 65 * Fischer-Piette, E., 1950. Listes des types décrits dans le Journal de Conchyliologie et conservés dans la collection de ce journal. Journal de Conchyliologie 90: 8-23

External links

Biodiversity Heritage Library (2 publications)

Encyclopedia of Life

World Register of Marine Species
* {{Taxonbar, from=Q5125725 thomasi Gastropods of Australia Gastropods described in 1862