This limpet has a humped, smooth shell with variegation in colour, usually pinkish, orangey, cream or purplish. It has a fairly thick shell with a shelf on the underside, which resembles a slipper. Shell length 5cm. Shell height 2.5cm.
It is found on the lower shore, attached to rocks and other shells, and they form stacks of up to ten individuals or more. They begin life as males, and then change progressively to become females. An introduced species from north-east America in 1887, the Slipper Limpet is quite an invasive species which competes with native oysters for space and food, and is also a threat to Common Mussel beds. Common and widespread.
Photographs of American Slipper Limpet (Crepidula fornicata), taken August 2012, Bournemouth, Dorset, . © Pete Hillman 2012. Camera used Nikon Coolpix P500.