Cantharidella picturata
A variable marine snail endemic to southeastern Australia.
Cantharidella picturata, called the painted kelp shell, is a marine gastropod mollusk in the Trochidae family, the top snails. This small, conical shell has a narrow umbilicus and ranges from 4 mm to 8 mm in size. Its coloration is highly variable, with common patterns including a whitish base marked by broad or narrow red or crimson flames that extend to the shell’s edge, often interrupted by a dotted zone, and with red dots on the base. Another pattern shows a clear yellowish or whitish ground with red dots on the spiral ridges, sometimes with short red flames near the sutures. A third variety is entirely purplish black, with a green-tinged umbilicus. Except for the dark variety, all forms are whitish around the umbilicus, and the inside of the umbilicus and the columella are tinged with green. The spire is elevated, conical, and somewhat blunt, with impressed sutures. The five to six whorls are convex and encircled by spiral ridges—usually five or six on the penultimate whorl, though this varies. The body whorl has a prominent rib at the periphery and is convex underneath. The aperture is quadrangular, delicately ribbed inside, and iridescent with a predominance of green. The columella curves above, then runs straight and oblique, ending near the base in a slight denticle. This attractive little shell is typically either flamed with dark red or dotted all over with pink, and the ground color may sometimes have a green or pink cast. The species is endemic to Australia, found off Queensland, New South Wales, Victoria, and Tasmania.
Quick Facts
- Taxon
- Cantharidella picturata
Facts from the source article.
Lore & Background
The shell of Cantharidella picturata is conical, with an elevated, rather obtuse spire and impressed sutures. The five to six whorls are convex and encircled by lirae, usually five or six on the penultimate whorl but very variable. The body whorl shows a prominent rib at the periphery and is convex beneath. The aperture is quadrangular, delicately ribbed within and iridescent, with green predominating. The columella is arcuate above, then straight and oblique, terminating near the base in a slight denticle.
Coloration is excessively variable. The most usual patterns include: whitish with longitudinal broad or narrow red or crimson flames reaching to the periphery, with the ground-color and base dotted red (the flames frequently interrupted in the middle by a dotted zone); a clear yellowish or whitish ground-color with the lirae dotted red, sometimes showing short red flames under the sutures; and a purplish black entire surface with a green-tinged umbilicus. Except the last variety, all are whitish around the umbilicus, and in all varieties the inside of the umbilicus and the columella are tinged with green. The ground-color sometimes has a green cast or is pink.
Reader's Guide
Cantharidella picturata is a small but visually striking species within the Trochidae family, endemic to Australian waters from Queensland to Tasmania. Its significance lies in its remarkable color variability, which the source describes as 'excessively variable' with several distinct patterns documented. The shell's iridescent aperture, with green predominating, and the green-tinged umbilicus and columella are consistent features across most color forms. The species is noted for its narrow umbilicus and conical shape, with a prominent peripheral rib on the body whorl. The source emphasizes that the number of lirae on the penultimate whorl is very variable, and the coloration patterns include flames, dots, and solid purplish black forms. This variability makes it a notable example of intraspecific shell patterning in Australian marine gastropods. The species is recorded from multiple Australian states, indicating a relatively broad temperate distribution. The source does not provide information on habitat, ecology, or conservation status.
Did You Know?
- The shell size varies between 4 mm and 8 mm.
- The columella terminates near the base in a slight denticle.
- The aperture is iridescent, with green predominating.
- The species is endemic to Australia, occurring off Queensland, New South Wales, Victoria and Tasmania.
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