what do common periwinkles eat and where is the food found
Common periwinkles are herbivores, using their file-like tongue, the radula, to feed on diatoms and algae attached to intertidal rocks. The common periwinkle breaks down its food by mixing it with mucous on the radula before bringing the food into its mouth. Sea stars, whelks, and some fish eat common periwinkles.ommon Periwinkle (Littorina littorea). Alternate common names: Periwinkle, Winkle. Color: Shell is dark in color, usually brown, black, or gray. Size: 1 inch long and 3/4 inch wide.