''Gibbula fanulum'' 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 ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.

Description

The size of the shell varies between 9 mm and 19 mm. The solid, umbilicate or perforate shell has a conical shape. It is whitish, radiately maculated above and dotted beneath with red or rich brown. There are several color mutations. The conical, 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. Spires are ...

is acuminate and somewhat scalariform. The about 7

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 are very convex, spirally lirate, and radiately costate above. They are bicarinated at the periphery, and encircled by a deep canal. The convex base of the shell bears about 5 spiral lirae. The oblique

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 rounded. 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 wo ...

is sinuous in the middle (not concave, nor dentate at the base as in '' Rubritrochus declivis'' (Forskål, 1775)) and arcuate above. The broad umbilicus is funnel-shaped, or narrow and almost closed,Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution

This marine species occurs off Southern

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

and in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

References

* Gmelin, J. F. 791 ''Caroli a Linné, systema naturae. Tom. I. Pars VI''. – pp. 3021–3910. Lipsiae * Lamarck ( .-B. M.de), 1815–1822: ''Histoire naturelle des animaux sans vertèbres''; Paris ol. 5: Paris, Deterville/Verdière ol. 6 published by the Author7 vol. molluschi sono compresi nei vol. 5–7. Vol. 5 (Les Conchiferes): 612 pp. [25 luglio 1818 Vol. 6 (1) (Suite): 343 pp. [1819]. Vol. 6 (2) (Suite): 232 pp. [1822]. Vol. 7: (Suite): 711 pp. (1822) * Risso A., 1826–1827: ''Histoire naturelle des principales productions de l'Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes''; Paris, Levrault Vol. 1: XII + 448 + 1 carta 826 Vol. 2: VII + 482 + 8 pl. (fiori) ovembre 1827 Vol. 3: XVI + 480 + 14 pl. (pesci) ettembre 1827 Vol. 4: IV + 439 + 12 pl. (molluschi) ovembre 1826 Vol. 5: VIII + 400 + 10 pl. (altri invertebrati) * Bucquoy E., Dautzenberg P. & Dollfus G., 1882–1886: ''Les mollusques marins du Roussillon. Tome Ier. Gastropodes.''; Paris, J.B. Baillière & fils 570 p., 66 pl. [pp. 1–40, pl. 1–5, February 1882; pp. 41–84, pl. 6-10, August 1882; pp. 85–135, pl. 11–15, February 1883; pp. 136–196, pl. 16–20, August 1883; pp. 197–222, pl. 21–25, January 1884; pp. 223–258, pl. 26–30, February 1884; pp. 259–298, pl. 31–35, August 1884; pp. 299–342, pl. 36–40, September 1884; p. 343–386, pl. 41–45, February 1885; p. 387–418, pl. 46–50, August 1885; pp. 419–454, pl. pl. 51–60, January 1886; p. 455–486, pl. 56–60, April 1886; p. 487–570, pl. 61–66, October 1886] * Beck L., 1995: ''Rubritrochus, a new genus name for Gibbula pulcherrima A. Adams 1855 and Gibbula declivis (Forskal 1775)''; Archiv für Molluskenkunde 124(1–2): 65–85 * 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

* {{Taxonbar, from=Q5559014 fanulum Gastropods described in 1791