of Freshwater Mussels
by Robert E. Warren
ISM Associate Curator of Anthropology
Where Do Mussels Live?
Mussels generally live half-buried in gravel, sand, or mud on the bottoms
of streams and lakes. Some species prefer to live in large rivers, while
others are adapted to small creeks or to ponds or lakes with standing
water. Mussels that live in moving water often have shells that are
heavy or are sculptured on the outside. Weight and sculpturing help
anchor mussels in river beds and prevent them from being washed away.
Mussels that live in lakes or ponds tend to have thin, unsculptured
shells. Illustration: Bed
of spectaclecase mussels (Cumberlandia monodonta) in a Missouri
river. (Use the Back button to return here after viewing link)
Long Do Mussels Live?
Like trees, mussels deposit annual growth rings in their shells. Some
species have a life expectancy of about 10 years, but others live to
be more than 100 years old.
Growth rings on a
sugarspoon mussel (Epioblasma triquetra).
Do Mussels Do For a Living?
Mussels are filter feeders. They eat tiny animals (protozoa) and plants
(algae) that they filter from water passing across their gills. Mussels
are good for the environment because their filter feeding helps make
water clear. They are also an important food resource for muskrats,
raccoons, river otters, and some fish.
Click on the images below see larger images of protozoa and algae.
A mussel can use its foot to move short distances, but once it finds
a place it likes it will generally remain there until its environment
changes. For example, mussels will attempt to move toward deeper water
when water levels drop during droughts. However, mussels don't make
long trips—unless they get swept away by flood waters.
Mussel Diorama (html) (pdf)