''Vasum truncatum'' 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 ...

of large

predatory Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

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 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 ...

within the family Turbinellidae.MolluscaBase eds. (2023). MolluscaBase. Vasum truncatum (G. B. Sowerby III, 1892). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=582334 on 2023-01-28 ;Subspecies: * ''Vasum truncatum triangulare'' (E. A. Smith, 1902) * ''Vasum truncatum truncatum'' (G. B. Sowerby III, 1892)

Description

The length of the shell attains 71 mm. (Originally described as ''Turbinella truncata'') The solid, white shell has a subcylindical-turbinate shape. It is truncated and obtusely angulated. The shell contains eight

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, including two flat, papillate whorls of the

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

. The anterior portion answering to the rostrum in the typical form as in ''

Turbinella pyrum ''Turbinella pyrum'', common names the chank shell, sacred chank or chank, also known as the divine conch, sometimes referred to simply as a conch, is a species of very large sea snail with a gill and an operculum, a marine gastropod mollusk ...

'' (Linnaeus, 1767) is quite half as broad as the widest part of the shell, and the anterior part of the elongated, white

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 ...

is so little narrower than the posterior, that it can scarcely be called a

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 ...

. The four small, slightly oblique plaits are situated about (or a little below) the middle of the columella. Sowerby, G. B. III. (1892). Marine shells of South Africa. A catalogue of all the known species with references to figures in various works, descriptions of new species, and figures of such as are new, little known, or hitherto unfigured, London: G. B. Sowerby. 89 pp., 5 pls
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Distribution

This marine species occurs off

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

References

* Marais J.P. & Kilburn R.N. (2010) Turbinellidae. Pp. 300-310, in: Marais A.P. & Seccombe A.D. (eds), Identification guide to the seashells of South Africa. Volume 1. Groenkloof: Centre for Molluscan Studies. 376 pp. * Steyn, D. G.; Lussi, M. (2005). Offshore Shells of Southern Africa: A pictorial guide to more than 750 Gastropods. Published by the authors. pp. i–vi, 1–289.

External links

Abbott, R. T. (1959). The family Vasidae in the Indo-Pacific. Indo-Pacific Mollusca. 1 (1): 15-32
{{Commons category truncatum Gastropods described in 1892