{{Short description|Genus of sea snails}} {{Use dmy dates|date=July 2020}} {{Use British English|date=June 2022}} {{Automatic taxobox |image=Calliostoma ligatum 2.jpg |image_caption=A live individual of ''Calliostoma ligatum'' with the operculum showing at the back (on the left) |display_parents=3 |taxon=Calliostoma |authority= Swainson, 1840 |type_species=''Trochus conulus'' |type_species_authority=Linnaeus, 1758 |synonyms_ref=<ref name="WoRMS">{{WRMS species|138584|''Calliostoma'' Swainson, 1840||30 October 2010}}</ref> |synonyms={{Collapsible list|{{Species list |Ampullotrochus|Monterosato, 1890 |Calliostoma (''Ampullotrochus'')|Monterosato, 1890 |Calliostoma (''Calliostoma'')|Swainson, 1840 |Calliostoma (''Elmerlinia'')|Clench & R. D. Turner, 1960 |Calliostoma (''Eucasta'')|Dall, 1889 |Calliostoma (''Kombologion'')|Clench & R. D. Turner, 1960 |Calliostoma (''Leiotrochus'')|Conrad, 1862 |Callistoma|Herrmannsen, 1846 |Callistomus|Herrmannsen, 1846 |Conulus|Nardo, 1841 |Elmerlinia|Clench & Turner, 1960 |Eucasta|Dall, 1889 |Fluxina |Dall, 1889 |Jacinthius|Monterosato, 1889 |Kombologion|Clench & Turner, 1960 |Leiotrochus|Conrad, 1862 |Trochus (Calliostoma)|Swainson, 1840 |Trochus (Ziziphinus)|Gray, 1842 |Trochus (Zizyphinus)|Gray, 1847 |Ziziphinus|Gray, 1842}} * ''Zizyphinus'' [sic]}} }}
[[File:C. trotini.jpg|thumb|Apertural view of a shell of ''Calliostoma trotini'']] '''''Calliostoma''''' is a genus of small to medium-sized sea snails with gills and an operculum, marine gastropod molluscs within the family Calliostomatidae, the '''Calliostoma top snails'''. Previously this genus was placed within the family Trochidae. ''Calliostoma'' is the type genus of the family Calliostomatidae.
== Description == The name of this genus is derived from the Greek words ''kallos'' (beautiful) and ''stoma'' (mouth), referring to the pearly aperture of the shell. The genus ''Calliostoma'' is known in fossil records from the Upper Cretaceous onwards.<ref>Shimer & Shrock (1944). ''Index fossils of North America''.</ref>
The thin, acute, coeloconoid (approaching conical shape but with concave sides) shell is imperforate or rarely umbilicate. The whorls are smooth, often polished and spirally ridged or granular. The body whorl is angulated at the periphery. The aperture is quadrangular, sinuated at the base and slightly oblique. The columella is simple, usually ending anteriorly in a slight tooth.<ref>Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia</ref> The nucleus appears to be either dextral or sinistral indifferently.<ref>Dall W. H. 1889. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877–78) and in the Caribbean Sea (1879–80), by the U.S. Coast Survey Steamer "Blake", Lieut.-Commander C.D. Sigsbee, U.S.N., and Commander J.R. Bartlett, U.S.N., commanding. XXIX. Report on the Mollusca. Part 2, Gastropoda and Scaphopoda. Bulletin of the Museum of Comparative Zoölogy at Harvard College 18: 1–492, pls. 10–40</ref><ref>Swainson, W. 1840. ''A treatise on malacology, or shells and shell-fish''; London</ref>
== Species == {{Main|List of Calliostoma species}} As of 2022, ''Calliostoma'' is treated as a very broad genus of about 300 accepted species.<ref>{{Cite web |title=WoRMS - World Register of Marine Species - Calliostoma Swainson, 1840 |url=https://www.marinespecies.org/aphia.php?p=taxdetails&id=138584 |access-date=2022-12-03 |website=www.marinespecies.org |language=en}}</ref> While current information is too fragmentary to assign all species in a revised genus, it is expected to be broken up and (some) subgenera will be elevated to the status of genus.{{Cn|date=August 2023}}
== Distribution and habitat == The distribution of this genus is worldwide, found mainly on hard substrates, although Japanese species have been found on sandy bottoms. These snails occur from shallow waters to bathyal depths.
== Behaviour and ecology == The species in this genus are mainly herbivorous or feed on detritus,<ref>Clench W. & Turner R. (1960). "The genus ''Calliostoma'' in the western Atlantic". ''Johnsonia'' '''4'''(40) :1-80.</ref> although a few have been observed to be omnivorous (Keen, 1975) or even carnivorous, feeding on a wide range of algae and on animals belonging to various other invertebrate phyla.<ref>{{cite journal |last1=Perron |first1=F. E. |year=1975 |title=Carnivorous ''Calliostoma'' (Prosobranchia: Trochidae) from the northeastern Pacific |journal=Veliger |volume=18 |pages=52–54}}</ref> The North Atlantic topshell ''Calliostoma occidentale'' has been reported to feed on coelenterates.<ref name="Perron">{{cite journal |last=Perron |first=Frank E. |author2=Turner R. D. |year=1978 |title=The feeding behaviour and diet of ''Calliostoma occidentale'', a coelenterate-associated prosobranch gastropod |url=http://mollus.oxfordjournals.org/cgi/pdf_extract/44/1/100 |url-status=dead |journal=Journal of Molluscan Studies |volume=44 |issue=1 |pages=100–103 |archive-url=https://archive.today/20130415183640/http://mollus.oxfordjournals.org/cgi/pdf_extract/44/1/100 |archive-date=15 April 2013 |access-date=20 May 2010}}</ref>
Contrary to what is the case in most other top shells, species of the genus ''Calliostoma'' deposits their eggs in gelatinous ribbons that are only fertilized ''after'' being deposited. The young emerge as small snails (Lebour, 1936) without passing through a free-living planktonic stage as a veliger larva.
==Gallery== <gallery> File:Calliostoma bairdii drawing.jpg|Drawing of a dorsal view of a living animal of ''Calliostoma bairdii'' dredged in the Atlantic Ocean at a depth of from 100m to 1170m. File:Calliostoma supragranosum.jpg|Rare purple beaded specimen of Calliostoma supragranosum found subtidally in Southern California. File:Calliostoma formosense 01.JPG|These shells are from the species Calliostoma formosense, originating from the island of Taiwan. </gallery>
==References== {{Reflist}} * Vilvens C. (2012) ''New species and new records of Seguenzioidea and Trochoidea (Gastropoda) from French Polynesia''. Novapex 13(1): 1–23. [10 March 2012] page(s): 18
==Further reading== *{{cite journal |author=Marshall, B.A.|title=A revision of the recent ''Calliostoma'' species of New Zealand|journal=The Nautilus|year=1995|volume=108|pages=83–127|url=https://www.biodiversitylibrary.org/page/8273356#page/111/mode/1up}} * {{cite journal |author=Quinn, J.F. Jr.|title=New species of ''Calliostoma'' and notes on some poorly known species from the Western Atlantic|journal=The Nautilus|year=1992|volume=106|pages=77–114}} *{{Cite web|url=http://www.malacolog.org/|title=Malacolog 4.1.0: : A database of Western Atlantic Marine Mollusca|access-date=18 March 2009|year=2005|author=Rosenberg G.|archive-url=https://web.archive.org/web/20150924211501/http://www.malacolog.org/|archive-date=24 September 2015|url-status=dead}} * {{cite journal|last=Williams|first=S.T. |author2=K.M. Donald |author3=H.G. Spencer |author4=T. Nakano|title=Molecular systematics of the marine gastropod families Trochidae and Calliostomatidae (Mollusca: Superfamily Trochoidea) |journal=Molecular Phylogenetics and Evolution|date=March 2010|volume=54|series=3|pages=783–809|doi=10.1016/j.ympev.2009.11.008|pmid=19919851|issue=3}} * Vilvens C. (2009). ''New species and new records of Calliostomatidae (Gastropoda: Trochoidea) from New Caledonia and Solomon Islands''. Novapex 10(4): 125-163
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Category:Calliostoma Category:Gastropod genera Category:Taxa named by William Swainson