Shell of the Week: The Gulf Stream Top Snail
Calliostoma scalenum Quinn, 1992 is a locally rare top snail that can reach up to 40 mm in parts of its distribution range. The shell bears a sculpture of spiral cords of two different widths, with symmetrical rather than spirally elongate beads. The shell color ranges from light chestnut-brown to red-brown, with the umbilicus and aperture of lighter color. The species lives in deeper water than the relatively similar Calliostoma tampaense. Only one shell of this species (photo) has been on record so far as found on Sanibel-Captiva beaches. It was collected by Len Geyer in early 2015 at the Lighthouse Beach on Sanibel.