''Astralium haematragum'', common name the Pacific star shell, 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
sea snail, a marine
gastropod 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 group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Turbinidae
Turbinidae, the turban snails, are a family of small to large marine gastropod molluscs in the superfamily Trochoidea.Bouchet, P. (2014). Turbinidae Rafinesque, 1815. Accessed through: World Register of Marine Species at http://www.marinespecies ...
, the turban snails.
Description
The size of the shell varies between 15 mm and 25 mm. The imperforate shell is pale ashen. It has an elevated-conic shape with an acute
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, ...
. The seven
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 are planulate above, with radiating oblique folds, which are produced into short spines at the periphery. The
body whorl is carinated, with ten to twelve spines in a single series. The base of the shell is plano-concave, concentrically squamose-lirate. 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 ...
is transverse, channelled at the carina. The
columella
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire.
His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...
is arcuate, purple or blue margined, dentate at its base.
G.W. Tryon (1888), Manual of Conchology X; Academy of Natural Sciences, Philadelphia
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Distribution
This marine species occurs in the Southwest Pacific and off Japan.
References
* Williams, S.T. (2007). ''Origins and diversification of Indo-West Pacific marine fauna: evolutionary history and biogeography of turban shells (Gastropoda, Turbinidae).'' Biological Journal of the Linnean Society, 2007, 92, 573–592.
* Alf A. & Kreipl K. (2011) ''The family Turbinidae. Subfamilies Turbininae Rafinesque, 1815 and Prisogasterinae Hickman & McLean, 1990''. In: G.T. Poppe & K. Groh (eds), A Conchological Iconography. Hackenheim: Conchbooks. pp. 1–82, pls 104–245.
External links
Gastropods.com: ''Astralium haematragum''
{{DEFAULTSORT:Astralium Haematragum
haematragum
Gastropods described in 1829