''Rubritrochus declivis'', the sloping gibbula, is a
species of
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 in the
family Trochidae, the top snails.
Description
The shell grows to a length of 24 mm. The umbilicate, conical shell is solid. It is whitish, and maculated with purplish or yellowish. The six
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 bicarinate at the periphery, all over spirally lirate. The upper surface is strongly radiately costate. The folds terminate at the periphery in short spines. The periphery is encircled by a channel bearing a median riblet. The base of the shell is convex, bearing 4 or 5 strong concentric lirae. The rounded aperture is smooth within. The
columella is sinuous, arcuate, and dentate at the base. The
umbilicus is moderate deep.
This species is separated from all others in this genus by the scalariform spires, strongly plicate upper surface, and the deep channel encircling the periphery.
Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
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Distribution
This species occurs in the Red Sea and the Gulf of Aqaba
References
* Moazzo, P. G. (1939). ''Mollusques testacés marins du Canal de Suez.'' Mémoires de l’Institut d’Égypte. 38: 1–283, pl. 1-14 + frontispice, maps 1–4.
* Vine, P. (1986). ''Red Sea Invertebrates''. Immel Publishing, London. 224 pp
* Beck L.A. (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
External links
*
{{DEFAULTSORT:Rubritrochus Declivis
declivis
Molluscs described in 1775