''Heterocithara concinna'' is a species of

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 in the family Mangeliidae.WoRMS (2009). Heterocithara concinna Hedley, 1922. In: MolluscaBase (2017). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=434001 on 2017-07-16

Description

The length of the shell attains 5 mm, its diameter 1.5 mm. (Original description) The shell is small, slender and cylindro-fusiform. Its colour is pale buff, with a few broken ferruginous lines on the back of 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 ...

, on the varix, and in the subsutural intercostal spaces. The shell contains 7

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, rounded, constricted at the suture, and subangled at the shoulder. 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 ...

contains 2½ whorls, smooth, symmetrical, andconical. The sculpture shows prominent, narrow ribs, as broad as their interstices, proceeding from suture to base, but discontinuous from whorl to whorl. The spirals are sharp widely spaced threads traversing both ribs and interstices, but more conspicuous in the latter, amounting to four on the penultimate and thirteen on the body whorl, the one on the shoulder being more important than the rest. Besides the major spiral other close and minute threads overrun the fasciole area. The aperture is wide and unarmed. The

varix A varix (pl. varices) is an abnormally dilated vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels. Examples of varices include: * Varicose veins, large tortuous veins usua ...

is narrow but elevated. The sinus is deeply excavate. 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 ...

is short and wide. Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213–359, pls 42-56

Distribution

This marine species is endemic to Australia and occurs off Queensland.

References

External links

Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1–1295
{{DEFAULTSORT:Heterocithara Concinna concinna Gastropods described in 1922 Taxa named by Charles Hedley