A Quick Guide to the Periwinkle Snail
The periwinkle snail is in the family Littorinidae and is known as a shore snail. These tiny snails are approximately 1-½ inches long and are found among rocks, on wood pilings between high and low tides, underneath docks, and in mud pools. The largest periwinkle snail, Littorina littorea, is the most common variety.
The periwinkle snail originated in Europe and was brought to Canada in the mid-1800s. It can be found all along the East Coast of the United States, from New England to Maryland. Many different types of shore and water birds feed on this snail as part of their diets. In some locations, such as the southern United States, all freshwater snails are also known as periwinkles.
The periwinkle snail has a hard shell for protection. It can live out of the water for quite a long time. In fact, when breeding, the female is out of the water more than in it. The eggs are kept in a brood sac and the periwinkle snail is housed in a transparent egg. When they are ready to be born, they crawl out of egg, looking like miniature versions of adults. Some periwinkles hold on to the eggs until the babies are born while others drop their eggs into the water.
While the periwinkle snail lays hundreds of eggs, very few will survive to be one year old. That’s because they are eaten by so many birds and other predators. The snail itself eats algae, which it finds growing on rocks. To accomplish this task the periwinkle snail has a special tooth arrangement, which is known as a radula. The snail’s teeth are hooked and very sharp, and those that break are replaced in one day. The teeth break easily because they are used to scrape rocks to acquire the algae and other types of plant scum.
The periwinkles are among the very small number of sea creatures which breathe air. So, if during low tide, you should see rocks covered with periwinkle snails, leave them alone. They are alive and well even if they are in cracks in the rocks, other shells, or just lying in the sand.
Sometimes, you may see a large number of periwinkles all spread out together across the rocks. They are simply waiting for a high tide to carry them back out to sea. There is a very large periwinkle snail which lives on mangrove trees. You can find them on the leaves, up and down the trunk and even in the roots of the tree.
The periwinkle snail uses its own mucus to attach its shell to the rocks and other surfaces at low tide. They also close their shell, sealing the opening with a tight-fitting plate-light closure.
That means if you want to eat a periwinkle snail, you need to stick something sharp in the opening like a toothpick or a pin and take out the meat. Periwinkle snails are edible and used in all types of dishes. Although not popular as of yet in America, they have been eaten for hundreds of years in England, China and other countries.
They say that in chowder, for instance, that periwinkles are undistinguishable from other shellfish. In fact, their name comes from Old English, “penny winkle,” as you could buy them for a penny per handful or two pennies per pound.
A periwinkle snail is very easy to find, whether you are collecting them for food or their shells. Just look around rocks, pools, and docks at low tide and you are sure to find thousands of them at a time.