Family: Harpidae. Considered to be one of the most handsome shells, Harp Shells feature a variegated pattern of pinks and purplish reds on a shiny globose shell. The raised axial ribs are suggestive of the strings of a harp, giving the group its name. Interesting Facts: These creatures have the ability to detach a small part of their foot. This sacrifice was thought to be a defense mechanism until one day a harp shell was observed being pursued by a box crab. The harp detached a small piece of the posterior end of its foot and the crab began to consume it. The Harp shell then circled around behind the crab and engulfed it in a thick coating of mucus and sand. The shell then began to consume the crab, turning the predator into the prey.