Blue topsnail, Western ridged top shell • Calliostoma ligatum
Photos by Christina Meschkat (top right), Angeleen Olson (bottom right), and Jenn Burt. Bottom left: blue topsnail operculum, the "door" that covers the shell's aperture. Note the circular shape of the operculum, matching this species' circular aperture.
Identification
The blue topsnail usually has a brown shell with light tan spirals, though colour and shade can vary a bit and may have a pinkish tinge. A blue inner layer shows when the shell is worn or damaged. The shell gets to 2.5 cm in diameter and has an overall rounded cone-shape with somewhat convex whorls. The aperture (opening) is rounded. When the snail emerges the bright orange sole of its foot may be visible. Identification may be made more difficult by a black alga that sometimes grows on the shell.
Habitat & Range
This snail is commonly encountered in tidepools as well as kelp and eelgrass beds along rocky shorelines. It is found from the intertidal to a depth of 30 m. Its range extends from central Alaska to southern California.
Similar Species
The shells of the purple-ring topsnail (Calliostoma annulatum) and the variegated top shell (Calliostoma variegatum) have beaded coils. Though the shells are similar in shape, this beaded texture helps distinguish them from the blue topsnail.
Intriguing Info
The blue topsnail crawls quickly away from sea stars such as the ochre star (Pisaster ochraceus). It is often found on giant perennial kelp (Macrocystis integrifolia) and other brown algae. It feeds on such algae, as well as diatoms, ascidians, sponges, bryozoans, and detritus.
iNaturalist
https://www.inaturalist.org/taxa/129920-Calliostoma-ligatum
The blue topsnail usually has a brown shell with light tan spirals, though colour and shade can vary a bit and may have a pinkish tinge. A blue inner layer shows when the shell is worn or damaged. The shell gets to 2.5 cm in diameter and has an overall rounded cone-shape with somewhat convex whorls. The aperture (opening) is rounded. When the snail emerges the bright orange sole of its foot may be visible. Identification may be made more difficult by a black alga that sometimes grows on the shell.
Habitat & Range
This snail is commonly encountered in tidepools as well as kelp and eelgrass beds along rocky shorelines. It is found from the intertidal to a depth of 30 m. Its range extends from central Alaska to southern California.
Similar Species
The shells of the purple-ring topsnail (Calliostoma annulatum) and the variegated top shell (Calliostoma variegatum) have beaded coils. Though the shells are similar in shape, this beaded texture helps distinguish them from the blue topsnail.
Intriguing Info
The blue topsnail crawls quickly away from sea stars such as the ochre star (Pisaster ochraceus). It is often found on giant perennial kelp (Macrocystis integrifolia) and other brown algae. It feeds on such algae, as well as diatoms, ascidians, sponges, bryozoans, and detritus.
iNaturalist
https://www.inaturalist.org/taxa/129920-Calliostoma-ligatum
References
Adams, M.J. (2006). Calliostoma ligatum (Blue topsnail). Beach Watchers. Washington State University. Accessed 22/10/2014.
Cowles, D. (2005). Calliostoma ligatum (Gould, 1849). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 22/10/2014.
Harbo, R. M. (2011). Whelks to whales: Coastal marine life of the Pacific Northwest [revised]. Madeira Park, BC: Harbour Publishing. P. 138
Lamb, A., and Hanby, B. (2005). Marine Life of the Pacific Northwest [electronic version]. Madeira Park, BC: Harbour Publishing.
Authors and editors of page
Christina Meschkat, Kelly Fretwell, and Brian Starzomski
Adams, M.J. (2006). Calliostoma ligatum (Blue topsnail). Beach Watchers. Washington State University. Accessed 22/10/2014.
Cowles, D. (2005). Calliostoma ligatum (Gould, 1849). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 22/10/2014.
Harbo, R. M. (2011). Whelks to whales: Coastal marine life of the Pacific Northwest [revised]. Madeira Park, BC: Harbour Publishing. P. 138
Lamb, A., and Hanby, B. (2005). Marine Life of the Pacific Northwest [electronic version]. Madeira Park, BC: Harbour Publishing.
Authors and editors of page
Christina Meschkat, Kelly Fretwell, and Brian Starzomski