''Gymnobela bairdii'', common name Baird's turrid, is a species of

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 ...

Raphitomidae Raphitomidae is a Family (biology), family of small to medium-sized sea snails, marine (ocean), marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families" ...

Description

The length of the shell varies between 10 mm and 55 mm. (Original description) The large, rather stout shell has a fusiform shape. It shows an elevated, acute, turreted

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 ...

and eight or nine obtusely shouldered, angular

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

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 ...

is large and somewhat inflated, with a broad, flattened or a slightly concave, sloping subsutural band, which is covered with distinct, strongly receding lines of growth and with more or less evident, raised, spiral cinguli and grooves. Below the subsutural band the whorls are obtusely angulated, but without a distinct carina. Commencing at the shoulder and extending a short distance below it are numerous oblique, not very elevated, longitudinal ribs, which fade out before reaching the middle of the whorls. The whole surface of the whorls, including the ribs, is covered with conspicuous, raised, spiral cinguli, between which there are two or three smaller ones, separated by deep concave grooves of about the same breadth. The whole surface is covered by distinct, raised lines of growth. 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 oblong-ovate and is rather large. 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 ...

is nearly straight, somewhat prolonged, its inner edge forming a slight sigmoid curve. 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 short, broad, narrowed at the tip and not recurved. 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 sharp and thin. The posterior sinus is broad and rather deep, with regularly rounded margins, corresponding to the lines on the subsutural band. Below the shoulder the lip projects considerably forward and then is somewhat flattened and recedes gradually to the base of the short and broad siphonal canal. The whorls of 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 " ...

are very small and generally eroded so far as to appear smooth. The shell is white or grayish white, without any distinct epidermis. The aperture is clear white. The animal is destitute of operculum and eyes.

Distribution

''G. bairdii'' can be found off the North American coast, ranging from

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

south to

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

, between depths of 1061 m and 4062 m.Tunnell, John W., Jr., Felder, Darryl L., & Earle, Sylvia A., eds. ''Gulf of Mexico Origin, Waters, and Biota, Volume 1: Biodiversity.'' Texas A&M University Press, 2009. 668.

References

* Figueira R.M. Andrade & Absalão R.S. (2012) ''Deep-water Raphitomidae (Mollusca, Gastropoda, Conoidea) from the Campos Basin, southeast Brazil.'' Zootaxa 3527: 1–27

External links

*
Verrill A. E. (1884). ''Second catalogue of mollusca recently added to the fauna of the New England Coast and the adjacent parts of the Atlantic, consisting mostly of deep sea species, with notes on others previously recorded.'' Transactions of the Connecticut Academy of Arts and Sciences, 6(1): 139-294, pl. 28-32

Rosenberg, G.; Moretzsohn, F.; García, E. F. (2009). Gastropoda (Mollusca) of the Gulf of Mexico, Pp. 579–699 in: Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Texas A&M Press, College Station, Texas
{{DEFAULTSORT:Gymnobela Bairdii bairdii Gastropods described in 1884