''Otukaia'' 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 ...

mollusc 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 esti ...

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 ...

Calliostomatidae Calliostomatidae is a family of sea snails within the superfamily Trochoidea and the clade Vetigastropoda.Gofas, S. (2013). Calliostomatidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetail ...

, the top shells. ''Otukaia'' has long been considered a subgenus of

Calliostoma ''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 ...

and is still treated as such by many authorities. Snails in this genus are characterized by their relatively large, silky-white, thin shell. They lack an umbilicus. Their spiral

whorls 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 d ...

are flat to slightly convex. The first three spiral cords can show some sculpture that may persist on later whorls. They have a rachidian

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

. They can be found worldwide in deep water. Some authors use ''Otukaia'' Ikebe, 1942 as a subgenus in ''

'' Swainson, 1840. The (sub)generic name ''Otukaia'' is in honor of the Japanese

malacologist Malacology is the branch of invertebrate zoology that deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, ...

Yanosuke Otuka (1903–1950), who described the type species ''Calliostoma kiheiziebisu'' Otuka, 1939. Otuka Y. (1939). "日本産エビスガヒ屬の一新種 A new ''Calliostoma'' from Japan". ''Venus'' 9(1): 27–29
CiNii

Species

The following species are accepted in the genus ''Otukaia'': * '' Otukaia beringensis'' Tuskes & R. Clark, 2018 * '' Otukaia ikukoae'' Sakurai, 1994 * ''

Otukaia kiheiziebisu ''Otukaia kiheiziebisu'' is a species of sea snail, a marine gastropod mollusk in the family Calliostomatidae. The type specimens were collected by amateur conchologist Mr. Kiheizi Oosima in 1938. The specific name ''kiheiziebisu'' is in hon ...

'' (Otuka, 1939) ;Species brought into synonymy: *''Otukaia blacki'' Dell, 1956, accepted as '' Maurea alertae'' (B. A. Marshall, 1995) *''Otukaia chilena'' (Rehder, 1971), accepted as '' Maurea chilena'' (Rehder, 1971) *''Otukaia crustulum'' Vilvens & Sellanes, 2006,Vilvens & Sellanes (2006). '' The Nautilus'' 120(1): 15-20. accepted as '' Calliotropis crustulum'' (Vilvens & Sellanes, 2006) *''Otukaia delli'' McLean & Andrade, 1982, accepted as '' Maurea delli'' (McLean & Andrade, 1982) *''Otukaia eltanini'' Dell, 1990, accepted as '' Maurea eltanini'' (Dell, 1990) *''Otukaia rossica'' (Dall, 1919), accepted as '' Margarites rossicus'' Dall, 1919

References

Calliostomatidae {{Calliostomatidae-stub