''Otukaia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of medium-sized

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s, which are

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 current power * Marine debris * Marine energy * Marine habitats * Mari ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 Trochid ...

and is still treated as such by many taxonomists. Snails in this genus are characterized by their relatively large, silky-white, thin shell, lacking an

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy *Umbilicus (plant), ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *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). In nature File:Photograph and axial plane floral diagram ...

are flat to slightly convex, with the first three whorls sometimes displaying sculpture that may persist on later whorls. They possess a rachidian

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks 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 enters ...

. These snails can be found worldwide in deep water. Some authors consider ''Otukaia'' Ikebe, 1942, a subgenus of ''

'' Swainson, 1840. The (sub)generic name ''Otukaia'' honors Japanese

malacologist Malacology, from Ancient Greek μαλακός (''malakós''), meaning "soft", and λόγος (''lógos''), meaning "study", is the branch of invertebrate zoology that deals with the study of the Mollusca (molluscs or mollusks), the second-largest ...

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 hono ...

'' (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 ''Nautilus'' is the fictional submarine belonging to Captain Nemo featured in Jules Verne's novels ''Twenty Thousand Leagues Under the Seas'' (1870) and '' The Mysterious Island'' (1875). Description ''Nautilus'' is described by Verne as ...

'' 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