The Common Periwinkle (Littorina littorea) is a small marine (saltwater) gastropod mollusc in the Littorinidae family of whelks and sea snails.
The Common Periwinkle has a thick, dark, grey-brown shell, that is sometimes banded. The inside of the shell is chocolate brown. It has 6-7 whorls. It has gills that enable it to breathe underwater. It has a lid on its shell, called an operculum.
It grows to 1-4 centimetres (1-2 inches) in length.
It is found in the Atlantic Ocean from the coast of Spain to Russia. It prefers intertidal locations and rocky shores, in reefs and lagoons.
The Common Periwinkle can move horizontally and vertically and can react to light and dark.
It is omnivorous, eating algae, barnacle larvae, and invertebrates.
It is oviparous. The female has egg capsules of 10,000 to 100,000 eggs that she releases into the sea. The eggs hatch into larvae. After 7-8 weeks, the larvae become periwinkles.
The average lifespan of the Common Periwinkle is 5-10 years.
Location of photographs: Aquarium de Paris-Cinéaqua, France
Photographer: Martina Nicolls
Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM