Demoulia abbreviata
A marine snail of the Nassariidae family from South African waters.
Demoulia abbreviata, called the obtuse demoulia, is a marine snail in the Nassariidae family—the group known as Nassa mud snails or dog whelks. Its shell, which ranges from 20 to 36 mm in size, is oval and swollen, colored whitish or chestnut, sometimes with darker spots. The deep, channel-like suture has a slightly rounded outer edge bordered by a white band broken by fawn blotches. The spire is stepped, made of six or seven nearly flat whorls, while the body whorl is very convex and larger than all the others combined. The shell surface has raised, equal ridges. The white opening is nearly round, narrow at the top and wider at the bottom. The thin outer lip is finely notched along the edge and has prominent transverse ridges inside. The curved columella is covered by the inner lip, which is flattened, wrinkled above, and from the middle to the base forms a thick, projecting callus ending in a clear fold and two small drops. This species lives off the coast of South Africa, from Saldanha Bay to South Transkei, and is sometimes trawled at depths of 85 meters.
Quick Facts
- Taxon
- Demoulia abbreviata
Facts from the source article.
Lore & Background
The shell of Demoulia abbreviata is ovate and ventricose, colored whitish or chestnut, sometimes marked with deeper spots. The suture is deep and canaliculated, with a slightly rounded exterior edge surrounded by a white band alternated with fawn-colored blotches. The scaffolded spire consists of six or seven nearly flat whorls, while the body whorl is very convex and larger than all others combined. The surface bears equal, raised striae. The white aperture is subrotund, narrowed at the upper part and dilated inferiorly. The thin outer lip is crenulated on the edge and marked interiorly with very prominent transverse striae. The columella is arcuated and covered by the inner lip, which is obliterated, flattened, and corrugated above; from the middle to the base it forms a thick, projecting callus terminated by a very apparent fold and two guttules.
Reader's Guide
Demoulia abbreviata is a representative of the Nassariidae family, commonly known as Nassa mud snails or dog whelks. Its shell morphology—particularly the deep canaliculated suture, convex body whorl, and distinctive columellar callus with a fold and two guttules—helps distinguish it within the group. The species is recorded from Saldanha Bay and South Transkei in the Republic of South Africa, and has been trawled at a depth of 85 metres. The shell size range of 20 mm to 36 mm places it among the moderate-sized nassariids. The color pattern of whitish or chestnut with fawn blotches and a white band is characteristic. The species was originally described by Gmelin in the 1791 edition of Systema Naturae, and later included in the 2010 identification guide to South African seashells by Marais and Kilburn. Its occurrence in specific South African waters contributes to the regional biodiversity of marine gastropods.
Did You Know?
- The shell size of Demoulia abbreviata varies between 20 mm and 36 mm.
- This species occurs off Saldanha Bay and South Transkei, Republic of South Africa.
- The columella is arcuated and covered by an inner lip that forms a thick callus with a fold and two guttules.
More in Marine Snails: Ceriths, Nassas and Conchs, Part 2 1-24
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