''Gemmula vagata'' 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

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 ...

Turridae Turridae is a taxonomic family name for a number of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). Accessed through: World Register of Marine Specie ...

, the turrids.

Description

The length of the shell varies between 60 mm and 65 mm. The tall and narrow fusiform shell is white with the infrasutural keel somewhat reddish. The

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 elongate and acuminate with almost vertical sides. It contains 12

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, showing a moderately strong subsutural square-cut fold. The concave shoulder shows 5 to 9 spiral threads. It is strongly gemmate with about 24 gemmules on the penultimate whorl. 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 ...

with the

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

measures almost half the total length. The interior of the aperture is white. The outer lip is narrow and slightly incised. The columella stands upright and is slightly askew. The siphonal canal is elongate, narrow and slightly recurved. Smith, E.A., 1895. Natural History Notes from H.M. Indian Marine Survey Steamer 'Investigator' , Commander C.F. Oldham, R.N.- Series 2. No. 19. Report upon some Mollusca dredged in the Bay of Bengal and the Arabian Sea during the season 1893-94.. Annals and Magazine of Natural History 6 16:1-19, plates 1, 2

Distribution

This species occurs in deep water in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

from

Aden Aden ( ar, عدن ' Yemeni: ) is a city, and since 2015, the temporary capital of Yemen, near the eastern approach to the Red Sea (the Gulf of Aden), some east of the strait Bab-el-Mandeb. Its population is approximately 800,000 people. ...

Andaman Islands The Andaman Islands () are an archipelago in the northeastern Indian Ocean about southwest off the coasts of Myanmar's Ayeyarwady Region. Together with the Nicobar Islands to their south, the Andamans serve as a maritime boundary between th ...

and off

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

References

External links

Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1-1295

Gastropods.com: ''Gemmula (Gemmula) vagata''
{{DEFAULTSORT:Gemmula Vagata vagata Gastropods described in 1895