Steromphala divaricata

Steromphala divaricata, common name the divaricate gibbula, is a species of small sea snail, known as top snails or top shells, marine gastropod molluscs in the family Trochidae, the top snails.[1]

Steromphala divaricata
Shell of Steromphala divaricata
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Vetigastropoda
Order:	Trochida
Superfamily:	Trochoidea
Family:	Trochidae
Genus:	Steromphala
Species:	S. divaricata
Binomial name
Steromphala divaricata (Linnaeus, 1758)
Synonyms
Gibbula divaricata (Linnaeus, 1758) Gibbula divaricata var. diversa Monterosato 1888 Gibbula divaricata var. regularis Monterosato 1889 Gibbula divaricata var. scalaris Coen 1937 Gibbula specialis Coen 1937 Mondonta lessoni Payraudeau, 1826 Steromphala divaricata (Linnaeus, 1758) Trochus barbierii Brusina 1866 Trochus danili Brusina 1866 Trochus divaricatus Linnaeus, 1758 (basionym) Trochus lineolatus O. G. Costa, 1830 (invalid: junior homonym of Trochus lineolatus Risso, 1826) Trochus marginatus Brusina 1866 Trochus varians O. G. Costa, 1830

Distribution

It is found in the Mediterranean Sea, the Adriatic Sea and the Black Sea.

Description

The length of the shell is between 12 mm and 24 mm and is 16 mm to 19 mm wide. The conoidal shell is imperforate or narrowly perforate. It is very thick and solid, cinereous. The color of the shell is yellowish or green. It is longitudinally marked with rose-red lines, often oblique or broken into square dots. The spire is more or less elevated. Its outlines are rather convex. The six whorls are encircled by numerous lirulae, the upper ones flattened. The sutures are slightly impressed, but scalariform specimens with deep sutures are frequent. The body whorl is rounded at the periphery and on the base. The aperture is rounded-quadrate. The outer lip is bevelled to an edge, very thick and smooth within. The pearly columella is straightened in the middle. The umbilicus is narrow or concealed.[2]

References

1. MolluscaBase eds. (2020). MolluscaBase. Steromphala divaricata (Linnaeus, 1758). Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=576618 on 2020-12-30
2. G.W. Tryon (1889), Manual of Conchology XI p. 207-208

• Costa O. G., 1829: Catalogo sistematico e ragionato de' testacei delle Due Sicilie; Tipografia della Minerva, Napoli 8 + 132 p., pl. 1-3
• Brusina S., 1866: Contribuzione pella fauna dei molluschi dalmati; Verhandlungen der Kaiserlich-königlichen Zoologisch-botanisch Gesellschaft in Wien 16: 1-134
• Coen G., 1937: Nuovo saggio di una sylloge molluscorum Adriaticorum; Memoria Reale Comitato Talassografico Italiano 240, 1–173, 10 pls
• 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
• Kantor Yu.I. & Sysoev A.V. (2006) Marine and brackish water Gastropoda of Russia and adjacent countries: an illustrated catalogue. Moscow: KMK Scientific Press. 372 pp. + 140 pls.

External links

• "Gibbula divaricata". Gastropods.com. Retrieved 16 January 2019.
• Linnaeus, C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition, vol. 1: 824 pp. Laurentius Salvius: Holmiae]
• Payraudeau B. C., 1826: Catalogue descriptif et méthodique des Annelides et des Mollusques de l'île de Corse; Paris pp. 218 + 8 pl.
• Costa O. G. (1830 ["1829") Catalogo sistematico e ragionato de' testacei delle Due Sicilie. Tipografia della Minerva, Napoli. pp. 1-8, i-cxxxii, pl. 1-3]
• Monterosato T. A. (di), 1888-1889: Molluschi del Porto di Palermo. Specie e varietà; Bullettino della Società Malacologica Italiana, Pisa 13 (1888[1889?): 161-80 14 (1889): 75-81]