''Lucerapex casearia'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Turridae Turridae is a Taxonomy (biology), taxonomic family (biology), family name for a number of predatory sea snails, Marine (ocean), marine gastropod mollusks in the superfamily Conoidea.MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). ...

, the turrids. The subspecies ''Lucerapex casearia regilla'' Iredale, 1936 is a synonym of '' Pagodaturris regilla'' (Iredale, 1936) (basionym)

Description

The length of the shell attains 21 mm. (Original description) The thin, slender shell has a fusiform shape. The

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. Spire ...

is keeled and turreted. The base is contracted. The shell consists of 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). In nature File:Photograph and axial plane floral diagra ...

s, including a 1½ whorls 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 " ...

, parted by linear rather oblique impressed sutures. The colour varies from pearl grey to pale orange, usually cheese colour.

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 ...

: the paucispiral protoconch is glassy with rounded whorls, the adult smooth and somewhat glossy though duller than the protoconch. The periphery is sharply produced into a projecting keel. The fasciole is set with pointed radiating tubercles, of which the penultimate whorl bears eighteen. These tubercles continue upwards, diminishing proportionately to the protoconch. But downwards they degenerate on the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

to imbricating scales. The unarmed keel slightly rises at its termination, bringing the shelf above it nearer to the horizontal. The fasciole ends in a deep and narrow slit. The anal sinus is spout-like. 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 i ...

is open, produced, bent a little to the right. Under the lens, delicate growth lines appear which diverge acutely above and below the keel, crossing the base they are flexed. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is narrowly pyriform, a callus spread on the inner

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

. Hedley, C.; Petterd, W. F. (1906). Mollusca from three hundred fathoms off Sydney. Records of the Australian Museum. 6(211): pls.
/ref>

Distribution

This marine species is

endemic Endemism is the state of a species being found only 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 foun ...

to Australia and occurs off Sidney,

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

References

* Laseron, C. 1954. Revision of the New South Wales Turridae (Mollusca). Australian Zoological Handbook. Sydney : Royal Zoological Society of New South Wales pp. 56, pls 1–12. * Wilson, B. 1994. Australian marine shells. Prosobranch gastropods. Kallaroo, WA : Odyssey Publishing Vol. 2 370 pp.

External links

Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213-359, pls 42-56
{{DEFAULTSORT:Lucerapex Casearia casearia Gastropods described in 1906 Gastropods of Australia