''Steiraxis aulaca'' is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

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 es ...

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 ...

Cochlespiridae Cochlespiridae is a taxonomic family of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. This family is not well differentiated morphologically, and there is poor congruence between the molecular and shell characters. ...

.MolluscaBase eds. (2023). MolluscaBase. Steiraxis aulaca (Dall, 1896). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=434982 on 2023-11-09}

Description

The length of the shell attains 60 mm, its diameter 26 mm. (Original description) The large, solid shell is white and has a fusiform shape. It contains about 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 flo ...

s (nucleus eroded) covered with a pale straw-colored epidermis. The whorls are rounded, with rather distinct lines of growth crossed by numerous very sharp, narrow, prominent subequal spiral ridges with about equal or narrower interspaces. The periphery is formed by a sort of rib, on which stand two to four similar keels, but smaller than the others and more crowded. In front of the rib there is a faint constriction of the whorl. The keels are less prominent on 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 ...

, which is moderately long and recurved. On the penultimate whorl there are about 14 keels between the sutures. 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 elongate, reflecting 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 ...

, but without lirae. The outer

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

is very flexuous, with a broad, rather shallow anal sulcus behind, and is arched forward in front of the peripheral rib. The body is white, not callous. 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 ...

is thin, attenuated, and obliquely truncate in front, concave, twisted, exhibiting a pervious axis. The siphonal canal is shallow, not producing a fasciole. The initiatory part of the operculum is spiral.Dall, William Healey. ''Diagnoses of new species of mollusks from the west coast of America''; Proceedings of the United States National Museum v.18 (1895)
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Distribution

This species occurs in the Pacific Ocean off

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

and in the

Gulf of Panama The Gulf of Panama ( es, Golfo de Panamá) is a gulf of the Pacific Ocean off the southern coast of Panama, where most of eastern Panama's southern shores adjoin it. The Gulf has a maximum width of , a maximum depth of and the size of . The Pan ...

References

Kantor Y.I., Harasewych M.G. & Puillandre N. (2016). ''A critical review of Antarctic Conoidea (Neogastropoda).'' Molluscan Research. DOI: 10.1080/13235818.2015.1128523

External links

* {{DEFAULTSORT:Steiraxis Aulaca Taxa named by William Healey Dall Gastropods described in 1896