Encyclopedia Dubuque
"Encyclopedia Dubuque is the online authority for all things Dubuque, written by the people who know the city best.”
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Affiliated with the Local History Network of the State Historical Society of Iowa, and the Iowa Museum Association.
SPECTACLECASE
SPECTACLECASE. Mussel. The surface of spectaclecase shell is smooth to somewhat rough. It is brown in young shells and becomes dark brown to black and rayless with age. The mussel grows to a length up to 8 inches (20.3 cm).
The spectaclecase mussel lives in large rivers with swiftly flowing water. Favorite sites are among boulders in patches of sand, cobble, or in gravel where the current is reduced.
Although is is widely distributed, the mussel is absent from many areas where it formerly occurred. It is considered endangered in Illinois, Iowa, and Wisconsin.