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Eastern Pearlshell
(Margaritifera margaritifera)

Eastern PearlshellPhotograph courtesy of E. Nedeau

NH Conservation Status: Species of Greatest Conservation Need


NH State Rank Status: Vulnerable to extirpation or extinction (global – apparently secure)


Distribution: The Connecticut and Merrimack River watersheds.


Description: A medium sized to large mussel growing up to 6 inches. The shell is thick and elongate and may have a banana shape. Shell color ranges from brown to black and foot is white. Inside shell is usually white and pitted.


Commonly Confused Species: Eastern elliptio


Habitat: Cold streams or rivers that support salmon or trout populations. Prefers sand, gravel, and cobble substrates. Not found in lakes, ponds, or warmwater streams.


Life History: Host fish are Atlantic salmon and brook, rainbow, and brown trout.


Conservation Threats: The species prefers clean, cold, and oxygenated water. Therefore, habitat degredation can occur when riparian vegetation is reduced, runoff results in warming of water, eutrophication is increased from surrounding nutrient inputs, sedimentation, and increased acidity.


Fun Facts: The Eastern pearlshell is the only freshwater mussel in NH in the Family Margaritiferidae. It is also one of the longest-lived organisms known on earth with a maximum expectancy of greater than 100 years!



eastern pearlshell

A few examples of shells from old eastern pearlshell. Photo by E. Nedeau