Clanculus margaritarius
A marine top snail with a red shell dotted in black.
Clanculus margaritarius, called the beautiful clanculus, is a marine gastropod mollusk in the Trochidae family. Its shell is very solid, tall and cone-shaped, with a narrow false umbilicus. The shell is red or reddish brown with black dots, and the apex is rosy. The spire outlines are slightly concave toward the tip, and the spire has about seven whorls that are nearly flat on top with impressed, linear sutures. The body whorl descends toward the front and is encircled by about 13 or 14 granulose ridges, every second one—or sometimes every one—marked with black dots. The spaces between ridges have fine spiral and oblique striae. The base of the shell is convex, and the aperture is four-sided. Inside the outer lip there is a strong tubercle above and a few folds on the outer and lower parts. The short columella is oblique, with a very slight fold above, and ends at the base in a large, squarish, three-toothed tooth. The parietal area is finely wrinkled, and the umbilicus is bordered by a plicate rib. Shell size ranges from 9 mm to 20 mm. The coloring is normally reddish brown, pinkish-red, or yellowish-brown with black spots. This species has a wide distribution, occurring in the Central and East Indian Ocean, China, East India, Indo-China, Indo-Malaysia, Japan, Loyalty Islands, Malaysia, New Caledonia, New Zealand, Oceania, Papua New Guinea, Solomon Islands, Taiwan, Queensland, and Australia. The subspecies Clanculus margaritarius multipunctatus Jansen, 1995 is considered a synonym of Clanculus multipunctatus Jansen, 1995.
Quick Facts
- Taxon
- Clanculus margaritarius
Facts from the source article.
Lore & Background
The shell of Clanculus margaritarius is very solid and elate-conic in shape, narrowly false-umbilicate, and colored red or reddish brown with black dots, rosy at the apex. The spire contains about 7 whorls that are nearly flat above with linear, impressed sutures. The body whorl descends anteriorly and is encircled by about 13 or 14 granose lirae, every second one or, on some specimens, every one articulated with black dots. The interstices are finely spirally and obliquely striate. The base is convex, and the aperture is tetragonal. The outer lip bears within a strong tubercle above and a few plicae on the outer and lower part. The short columella is oblique, with a very slight fold above, deeply entering a profound, extremely narrow axial pit, and at the base terminating in a large squarish trifid tooth. The parietal tract is finely wrinkled, and the umbilicus is bounded by a plicate rib.
The coloring of Clanculus margaritarius is normally reddish brown, pinkish-red, and yellowish-brown with black spots. The phylum Mollusca is noted as highly diverse and rich in color variations, and studies of this family aim to understand pigmentation evolution. Coloring in shells can result from behavioral characteristics, environment, mating displays, diet, heritable traits, and defense mechanisms. Scientists use the visible coloring to search for genes involved in color synthesis.
Reader's Guide
Clanculus margaritarius is a species of sea snail in the family Trochidae, documented in numerous references from the 19th and 20th centuries, including works by Philippi (1846), Adams (1853), Melvill & Standen (1899), and others. Its wide distribution spans the Central and East Indian Ocean, China, East India, Indo-China, Indo-Malaysia, Japan, Loyalty Islands, Malaysia, New Caledonia, New Zealand, Oceania, Papua New Guinea, Solomon Islands, Taiwan, Queensland, and Australia. The species is also noted for a subspecies, Clanculus margaritarius multipunctatus Jansen, 1995, which is considered a synonym of Clanculus multipunctatus Jansen, 1995. The shell's distinctive black-dotted red or reddish-brown pattern and its solid, elate-conic form make it a recognizable member of the Trochidae. The article highlights that the phylum Mollusca, including this species, provides a valuable system for studying color evolution, as shell coloring can be linked to genetics, behavior, and environmental factors. This species contributes to broader research on pigmentation evolution in the natural world.
Did You Know?
- The shell size of Clanculus margaritarius varies between 9 mm and 20 mm.
- The columella terminates at the base in a large squarish trifid tooth.
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