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Marsh Periwinkle

Littorina irrorata

The marsh periwinkle is a small snail with a thick, spiraling shell. It lives in tidal marshes and wetlands throughout the middle and lower Chesapeake Bay.

Appearance:

• Spiraling, grooved shell
• Slightly pointed spire
• Varies in color from grayish-white to tan
• Reddish-brown flecks on the spiral ridges
• Grows to 1 inch

Habitat:

• Found in low, sheltered tidal marshes and wetlands
• Usually lives on needlerush and saltmarsh cordgrass stalks

Range:

• Common in the middle and lower Chesapeake Bay

Feeding:

• Grazes on algae and detritus on the surface of plants and the ground

Predators:

• Blue crabs, mud crabs and terrapins prey upon marsh periwinkles
• Avoids predators by climbing up marsh grass stalks

Reproduction and Life Cycle:

• Lays individual eggs into the water
• Eggs hatch into free-swimming larvae
• Larvae develop into small snails in mid-summer

Other Facts:

• Uses a gill to get oxygen from the water
• Marsh periwinkles are gastropods, a type of mollusk that includes whelks, snails and slugs

Sources and Additional Information:

• Life in the Chesapeake Bay by Alice Jane Lippson and Robert L. Lippson
• Chesapeake Bay: Nature of the Estuary, A Field Guide by Christopher P. White
• Animal Diversity Web: Littorina irrorata – University of Michigan Museum of Zoology
• Littorina irrorata – Smithsonian Marine Station at Fort Pierce