''Diloma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of medium-sized

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 ...

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 ...

s 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. (2010). Diloma Philippi, 1845. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=391149 on 2011-07-02 There is also a genus ''Diloma'', F.H.Wind & P.Cepek, 1979 a genus of

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

in the class

Prymnesiophyceae Prymnesiophyceae is a haptophyte class. Although it was originally described by Casper in 1972, it did not receive a Latin diagnosis (a requirement for valid publication under the International Code of Botanical Nomenclature The ''Internatio ...

Description

The solid shell is imperforate and depressed globose. It is slate-colored or black, sometimes (especially if worn) reddish or brownish. The conic

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 short. The apex is acute, usually reddish. The sutures are linear. 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 slightly convex, rapidly increasing and spirally obsoletely striate. 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 usually depressed or subconcave below the suture. The base of the shell is rounded, eroded and iridescent in front of 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 ...

. The aperture is huge, oblique iridescent. The outer lip is rather thin, not black-margined within; but bordered by a brilliantly iridescent band; The columella is concave, obsoletely subdentate below, very broad and flattened or excavated on the face. It is composed principally of an opaque white layer which also lines the base but does not extend to the edge of the lip. The length of the shell varies between 15 mm and 26 mm. Its diameter varies between 17 mm and 24 mm.

Distribution

This genus occurs in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, including

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

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 ...

, and other areas.

Species

Phylogram A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

of the species in the genus ''Diloma'': Other species in the genus not included in the phylogram include: * '' Diloma durvillaea'' Spencer, Marshall & Waters, 2009Spencer H. G., Marshall B. A. & Waters J. M. (2009). "Systematics and phylogeny of a new cryptic species of ''Diloma'' Philippi (Mollusca: Gastropoda: Trochidae) from a novel habitat, the bull kelp holdfast communities of southern New Zealand". '' Invertebrate Systematics'' 23: 19-25.
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* '' Diloma nanum'' Gould, 1861 Species brought into synonymy: * ''Diloma constellatum'' Souverbie, 1863: synonym of '' Austrocochlea constellata'' (Souverbie, 1863) * ''Diloma coracina'' Suter, H., 1909: synonym of '' Diloma arida'' (Finlay, 1927) * ''Diloma gaimardi'' Hutton: synonym of ''

Diloma aethiops ''Diloma aethiops'', whose common names include scorched monodont, spotted black topshell, and in the Māori language pūpū, pūpū-mai, or māihi is a species of small sea snail, a marine gastropod mollusc in the family Trochidae, subfamily Mo ...

Gmelin Gmelin may refer to: * Gmelin's test, a chemical test * Gmelin database, a German handbook/encyclopedia of inorganic compounds initiated by Leopold Gmelin People * Carl Christian Gmelin (1762–1837), German botanist, author of ''Flora Badensis ...

, 1791 * ''Diloma impervia'' (Menke, 1843): synonym of '' Oxystele impervia'' (Menke, 1843) * ''Diloma piperinum'' (

Philippi Philippi (; grc-gre, Φίλιπποι, ''Philippoi'') was a major Greek city northwest of the nearby island, Thasos. Its original name was Crenides ( grc-gre, Κρηνῖδες, ''Krenides'' "Fountains") after its establishment by Thasian colon ...

, 1849): synonym of '' Austrocochlea piperina'' (Philippi, 1849) * ''Diloma sinensis'' (Gmelin, 1791) :synonym of ''

Oxystele sinensis ''Oxystele sinensis'', common name the pink-lipped topshell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails. Description The size of the shell varies between 18 mm and 51 mm. Distribut ...

'' (Gmelin, 1791) * ''Diloma suavis'' (Philippi, 1849): synonym of '' Pictodiloma suavis'' (Philippi, 1849) * ''Diloma tabularis'' (Krauss, 1848): synonym of '' Oxystele tabularis'' (Krauss, 1848) * ''Diloma tigrina'' (Anton, 1838): synonym of '' Oxystele tigrina'' (Anton, 1838) * ''Diloma variegata'' (Anton, 1838): synonym of '' Oxystele variegata'' (Anton, 1838) * ''Diloma novaezelandiae'' Anton, 1839: synonym of '' Diloma subrostrata'' (Gray in Yate, 1835) * ''Diloma (Chlorodiloma) millelineata'' (Bonnett, 1864): synonym of '' Chlorodiloma millelineata'' (Bonnett, 1864) * ''Diloma (Fractarmilla) lenior'' Finlay, H.J., 1927: synonym of ''

Diloma bicanaliculata ''Diloma bicanaliculatum'', common name the knobbed top shell, is a species of small sea snail, a marine (ocean), marine gastropod mollusk, in the family (biology), family Trochidae, the top snails. The size of the shell varies between 10 mm ...

'' (Dunker, 1844)

References

* Williams S.T., Karube S. & Ozawa T. (2008) ''Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined''. Zoologica Scripta 37: 483–506

External links

* {{Taxonbar, from=Q3512321 Trochidae Taxa named by Rodolfo Amando Philippi Gastropod genera