Western Pearlshell Mussel

---

The western pearlshell mussel (Margaritifera falcata) is native to the western United States stretching from the California to Alaska coasts and inland to Wyoming, Utah, and Montana. The pearlshell has the largest distribution and is the longest living freshwater mussel in the western United States. The species reaches up to about six inches long and is characterized by long, slightly concave, thick shells, a dark brown to black coloration, and fleshy, tree-like papillae. This mussel requires a fish host to carry its offspring to a juvenile life stage, and the known hosts include salmonids native to the western United States. Like many other native North American mussel species, the western pearlshell mussel has been extirpated from much of its range.

Fun fact: The western pearlshell mussel can live for more than 100 years.