''Crassispira abdera'' 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 ...

Pseudomelatomidae Pseudomelatomidae is a family (biology), family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda (Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), Bouchet & Ro ...

Description

The shell of Crassispira abdera can reach up to 15mm in lengthand the 6mm in diameter. The small shell is acute and thin. It has a dull waxen color with a darker blotch behind 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 ...

and a dark brown

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 " ...

consisting of a smooth and polished

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. The nine subsequent whorls show a spiral

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 ...

of obscure fine threads. 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 ...

, in addition, there is a more prominent duplex thread in front of the suture on the base, where there are four other widely separated threads that are only prominent as nodules at their intersection with the line of the ribs. There are six or more finer threads 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 i ...

. The axial sculpture consists of (on the body whorl 7 or 8) ribs which appear at the periphery as conspicuous nodules and become obsolete on the base, except at the intersections mentioned previously. There are also fine, sharp, and close arcuate incremental lines on the anal fasciole. The peripheral nodules are more riblike and numerous on the earlier part of 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 ...

. The aperture is short and rather wide. The

anal sulcus The anal sulcus, also called the anal sinus or anal canal, in Gastropods is a notch, a shelly tube at the top of the Aperture (mollusc), aperture. It is the first notch close to the Suture (anatomy), suture. It houses the anal siphon through which t ...

is deep, oval, and almost tubular. The outer

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 ...

is moderately thickened, sharp-edged, and smooth inside, with a prominent knob behind it. The inner lip smooth with a rather thick layer of enamel continues down the

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

with a raised edge and a chink behind it. The siphonal canal is short and wide and hardly differentiated, with an inconspicuous siphonal fasciole.Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 (1920)
(described as ''Elaeocyma abdera'')

Distribution

This marine species occurs in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

off

Panama Bay The Panama Bay () is a large body of water off the coast of southern Panama, at . It is a part of the greater Gulf of Panama. Pollution Problems The Panama Bay is considered to be in an eutrophic state by the World Resources Institute. This ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

References

External links

* *
James H. McLean & Roy Poorman, A Revised Classification of the Family Turridae, with the Proposal of New Subfamilies, Genera, and Subgenera from the Eastern Pacific; The Veliger vol. 14, 1971
{{DEFAULTSORT:Crassispira Abdera abdera Gastropods described in 1919