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Macoma petalum
Image courtesy of Melissa Frey, Royal BC Museum
Macoma petalum
Taxonomic Group: Mollusks-Bivalves


Macoma petalum is a clam commonly known as the Atlantic Macoma. It was formerly treated as a synonym of M. balthica (the Baltic Clam), but is now recognized as being genetically distinct. It is native to the Northwest Atlantic, but the boundaries of its native range are unknown and require further study. Introduced populations are known from San Francisco Bay, California and Grays Harbor, Washington. It is typically found muddy upper intertidal locations and is tolerant of a wide range of salinities. It reaches high densities in some areas of San Francisco (particularly in Spartina marshes) and has become an important food item for crabs, fish and birds.

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Fofonoff PW, Ruiz GM, Steves B, Simkanin C, & Carlton JT (2018)
National Exotic Marine and Estuarine Species Information System.
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Marine Invasions Lab
Smithsonian Environmental Research Center

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