Gibbula umbilicalis

Gibbula umbilicalis
A shell of Gibbula umbilicalis
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Clade:	Vetigastropoda
Superfamily:	Trochoidea
Family:	Trochidae
Genus:	Gibbula
Species:	G. umbilicalis
Binomial name
Gibbula umbilicalis (da Costa, 1778)
Synonyms[1]
Gibbula obliquata (Gmelin, 1791) Gibbula obliquata var. gradata Pallary 1920 Trochus agathensis Récluz, 1843 Trochus cinereus Blainville, 1826 non Linnaeus, 1758 Trochus obliquatus Gmelin, 1791 Gibbula obliquata (Gmelin, 1791) Trochus sarniensis Norman 1888 Trochus umbilicalis da Costa, 1778 (original combination) Trochus umbilicatus Montagu, 1803 Trochus umbilicatus var. atropurpurea Jeffreys 1865 Trochus umbilicatus var. decorata Jeffreys 1865

Gibbula umbilicalis, common name the flat top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.^[1]

Description

The size of an adult shell varies between 10 mm and 22 mm. The shell is more depressed than Gibbula cineraria, and (although the base is flatter) never inclined to a pyramidal form. The spiral ridges are sharper and fewer, especially in the young. The coloring is different; both have a similar kind of marking, but in the present species the longitudinal rays or streaks are red, besides being broader and not half so many as in the other species. They are sometimes zigzag, instead of being broken into spots or interrupted by the sculpture. This species is striped, the other lineated. Just within the outer lip are two borders, one of yellow, the other of green variegated by red spots. This edging is minutely tubercled like shagreen.^[2]

Distribution

This marine species occurs in European waters and in the Mediterranean Sea off Morocco.

References

• Da Costa E. M., 1778: Historia Naturalis Testaceorum Britanniae; London: Millan, White, Elmsley & Robson XII + 254 + VIII p., 17 pl
• Montagu G., 1803: Testacea Britannica, or natural history of British shells, marine, land and the fresh-water, including the most minute: systematically arranged and embellished with figures; Romsey. London pp. XXXVII + 606 + 16 pl.
• Jeffreys J. G., 1862-1869: British Conchology; London, van Voorst Vol. 1: pp. CXIV + 341 [1862]. Vol. 2: pp. 479 [1864]. Vol. 3: pp. 394 [1865]. Vol. 4: pp. 487 [1867]. Vol. 5: pp. 259 [1869]
• Norman A. M., 1888: Museum Normanianum, or a catalogue of the Invertebrata of Europe, and the Arctic North Atlantic Oceans. IV Mollusca marina. V. Brachiopoda; Durham pp. 30
• Pallary P., 1920: Exploration scientifique du Maroc organisée par la Société de Géographie de Paris et continuée par la Société des Sciences Naturelles du Maroc. Deuxième fascicule. Malacologie (1912) ; Larose, Rabat et Paris pp. 108, 1 pl., 1 map
• Backeljau, T. (1986). Lijst van de recente mariene mollusken van België [List of the recent marine molluscs of Belgium]. Koninklijk Belgisch Instituut voor Natuurwetenschappen: Brussels, Belgium. 106 pp.
• 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
• Muller, Y. (2004). Faune et flore du littoral du Nord, du Pas-de-Calais et de la Belgique: inventaire. [Coastal fauna and flora of the Nord, Pas-de-Calais and Belgium: inventory]. Commission Régionale de Biologie Région Nord Pas-de-Calais: France. 307 pp

External links

• Gastropods.com: Gibbula (Gibbula) umbilicalis; accessed : 3 July 2011

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