Definition
A periwinkle is a small sea snail, typically found clinging to rocks and seaweed in the intertidal zone. They belong to the family Littorinidae and are known for their tolerance of fluctuating conditions. Periwinkles graze on algae, playing a crucial role in maintaining the balance of the intertidal ecosystem. Think of them as the mini-gardeners of the shoreline. Their shells come in various colors and patterns. They are a common sight on rocky shores.