''Tritia recidiva'' 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 ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

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 Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Nassariidae The Nassariidae, Nassa mud snails (USA), or dog whelks (UK), are a taxonomic family of small to medium-sized sea snails, marine gastropod mollusks in the clade Neogastropoda. "Dog whelk" also refers to ''Nucella lapillus''. Shell description T ...

, the nassa mud snails or dog whelks.MolluscaBase eds. (2021). MolluscaBase. Tritia recidiva (von Martens, 1876). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=890058 on 2021-09-08

Description

The shell grows to a length of 12 mm. It has a high, slightly cyrtoconoid (almost with the shape of a cone, but having convex sides)

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. Spires are ...

and a somewhat constricted

body whorl The body whorl is part of the morphology of the 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 gastropods In gastropods, the b ...

. 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 ...

consists of ca. 3 rather large and smooth

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. The first three

teleoconch The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some ...

whorls contain spiral cords and axial folds, which fade out on the next two except for the subsutural spirals. The body whorl resumes 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 very even, flattened cords much that are broader than the interspaces. 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 opt ...

is lanceolate. The outer lip is slightly thickened externally and bears 5–6 strong rounded denticles inside. The parietal callus is appressed and devoid of a parietal denticle. It continues into a

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 ...

r callus which has a rounded edge, slightly raised over 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 is ...

and bearing a few tubercles. The colour of the shell has a brownish hue over a white background. The subsutural and median cords are articulated with darker brown. The aperture is white.

Distribution

This species occurs in the Western Mediterranean Sea and in the Atlantic Ocean off

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References

* Adam W. & Glibert M. (1974). ''Contribution à la connaissance de Nassarius semistriatus (Brocchi, 1814). (Mollusca : Gastropoda).'' Bulletin de l'Institut Royal des Sciences Naturelles de Belgique 50(3): 1–78. * Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification.'' Collection Patrimoines Naturels, 50: pp. 180–213

External links

Watson, R. B. (1897). On the marine Mollusca of Madeira; with descriptions of thirty-five new species, and an index-list of all the known sea-dwelling species of that island. Journal of the Linnean Society of London, Zoology. 26(19): 233-329, pl. 19-20

Pallary, P. (1900). Coquilles marines du littoral du département d'Oran. Journal de Conchyliologie. 48(3): 211-422

Dautzenberg, Ph. (1889). Contribution à la faune malacologique des Iles Açores. Résultats des Campagnes Scientifiques Accomplies sur son Yacht par Albert Ier Prince Souverain de Monaco, I. Imprimerie de Monaco: Monaco. 112, IV plates pp

S.; Luque, Á. A.; Templado, J.; Salas, C. (2017). A national checklist of marine Mollusca in Spanish waters. Scientia Marina. 81(2) : 241-254, and supplementary online materia
* {{DEFAULTSORT:Tritia Recidiva Nassariidae Gastropods described in 1876