''Clavosurcula sibogae'' 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 ...

Cochlespiridae Cochlespiridae is a Taxonomy (biology), taxonomic family (biology), family of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. This family is not well differentiated morphologically, and there is poor congruence betwe ...

Description

The length of the shell attains 38 mm, its diameter 20 mm. (Original description) The thin, clavate shell has a convex

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 ...

, attenuated towards the

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics), a teenaged super villainess in the Marvel Universe * Ape-X, a super-intelligent ape in the Squadron Supreme universe *Apex ...

, with along, slender

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 ...

. It is pellucid and white. 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, of which about 1½ form a smooth, swollen nucleus. The whorls of the

teleoconch The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some ...

are keeled, the keel running in the 2 uppermost whorls a trifle above the linear suture, in the following whorls it is coalescing with the suture. On the

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

it has the appearance of a blunt, rounded rib, with a slight groove above it. The upper whorls are nearly straight, the last two slightly convex, the body whorl rapidly contracted below the keel. The

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

consists of numerous raised spiral striae, rather fine in upper part of whorls, very fine on a narrow zone just above the keel, coarser on the keel, much coarser on the basal part of body whorl and on the siphonal canal, which is long and slender. 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 ...

is rhomboid, with a moderately sharp angle above and an obtuse angle at the keel. The

peristome Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, ...

is thin, broken, according to the growth lines with a wide, deep sinus above, then strongly protracted. The columellar margin is nearly straight above, along the body whorl, then concave, the upper part at the siphonal canal straight, then strongly contorted to the left, with a thin layer of enamel, stronger at upper part of the siphonal canal. The interior of the aperture is smooth, but apparently striated by the transparency of the shell.Schepman, 1913. The prosobranchia of the Siboga expedition. Part IV -V - VI: Toxoglossa
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Distribution

This deep-sea species occurs in the

Flores Sea The Flores Sea covers of water in Indonesia. The sea is bounded on the north by the island of Celebes and on the south by Sunda Islands of Flores and Sumbawa. Geography The seas that border the Flores Sea are the Bali Sea (to the west), Java ...

, Indonesia.

References

External links

* {{DEFAULTSORT:Clavosurcula Sibogae sibogae