Marsh Periwinkle
Littorina irrorata
Marsh periwinkles cling to saltmarsh cordgrass at Money Point in Chesapeake, Va., on Oct. 25, 2015. Money Point is the site of wetlands restored by the Elizabeth River Project. (Photo by Will Parson/Chesapeake Bay Program)
Marsh periwinkles cling to saltmarsh cordgrass (Spartina alterniflora) at Money Point in Chesapeake, Va., on Oct. 25, 2015. Periwinkles rise and fall with each tide, feeding on algae growing on the blades of grass. (Photo by Will Parson/Chesapeake Bay Program)
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
Marsh periwinkles grow to 1 inch in length. Their spiraling, grooved shell has a slightly pointed spire and varies in color from grayish-white to tan. Reddish-brown flecks appear on the spiral ridges of the shell.
Feeding
The marsh periwinkle grazes on algae and detritus on the surface of plants and the ground.
Predators
Blue crabs, mud crabs and terrapins prey upon marsh periwinkles. It will avoid predators by climbing up marsh grass stalks.
Reproduction and Life Cycle
Marsh periwinkles lay individual eggs into the water. Eggs hatch into free-swimming larvae, which develop into small snails in mid-summer.
Did You Know?
- A marsh periwinkle use its gill to get oxygen from the water.
- Marsh periwinkles are gastropods, a type of mollusk that includes whelks, snails and slugs.
- These snails are known to practice "fungiculture": by chewing holes in the cordgrass and spreading waste across the cuts, the marsh periwinkle can "farm" fungus, their preferred food.
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
Quick Facts
Species
Native
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Habitat
Found in low, sheltered tidal marshes and wetlands, usually living on needlerush and saltmarsh cordgrass stalks.
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Range
Common in the middle and lower Chesapeake Bay.
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Diet
Feeds on algae and detritus
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Status
Stable
