Vernacular names: Boreal topsnail
The accepted name for this species is currently, Calliostoma occidentale (Mighels & C. B. Adams, 1842).
Conical shell up to 12mm in height with about seven whorls. The shell is thin and semi-transparent and golden to reddish lustre. Shell surface is sculptured with 4 or 5 spiral ridges some of which have knot-like swellings. The animal possesses three pairs of epipodal tentacles.
Key identification features
- Conical shell with flat sides and a pointed apex
- Breadth approximately equal to height
- Shell has only 4 to 5 spiral ridges at the end of the last whorl
Similar species
- Calliostoma zizyphinum has more than 5 spiral ridges
- Calliostoma granulatum has more than 5 spiral ridges
Ecology and behaviour
Lives on stones where it feeds on alcyonarians and hydroids.
Distribution and status
Rare. A northern species, recorded from the British Isles (mainly in the north), the Northern Isles and coast of Norway.
The map provided here shows the distribution of the species based on Conchological Society data.