''Asperdaphne perissa'' 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 ...

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 39 ...

Description

The length of the shell attains 7.4 mm, its diameter 2.9 mm. (Original description) The thin shell is ovate-fusiform and has an acuminate

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 ...

. it contains five

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 two in 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 latter subulate with spiral punctate grooves. The colour of the shell is dead white except a cinnamon protoconch. The sculpture shows spiral threads predominating, amounting 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 ...

to about thirty, not impinging on a broad anal fasciole, beneath this strong and widely spaced, becoming feebler and closer below the periphery, but waxing stronger on the back of 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 ...

. The penultimate carries six such spirals, then three, then two on the earlier whorls. The radials are stronger on the younger whorls, but decrease on the older. In the body whorl they fade away about the periphery, and in the penultimate scarcely reach across the whorl. In every case they are overridden by the spirals. 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 elliptical. The inner lip is overlaid by a substantial callus which, opposite the sulcus and at the base of the siphonal canal, is provided by a small but sharp tubercle. The outer lip is produced externally into a prominent

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 ...

, and beset within by a row of small tubercles. The siphonal canal is short and broad. Ch. Hedley (1909), Mollusca from the Hope Islands, north Queensland; Proceedings of the Linnean Society of New South Wales v. 34 p. 458

Distribution

This marine species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Australia and occurs off

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

References

* Hedley, C. 1909. ''Mollusca from the Hope Islands, north Queensland''. Proceedings of the Linnean Society of New South Wales 34(1): 420–466, pls 36–44 * Li B.-Q. aoquan& Li X.-Z. inzheng(2014) ''Report on the Raphitomidae Bellardi, 1875 (Mollusca: Gastropoda: Conoidea) from the China Seas.'' Journal of Natural History 48(17-18): 999-1025

External links

Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213-359, pls 42-56
* {{DEFAULTSORT:Asperdaphne Perissa perissa Gastropods described in 1909 Gastropods of Australia