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The Economic Value of Freshwater Mussels
Prior to the European colonization of
North America, American Indians
used them as food, as tools (spoons,
cups, digging tools), and as ornaments.
In the early 1900's, there was a short-
lived industry in harvesting them for
making buttons, for decorative inlays,
and for their pearls. Today they are
being used to make seed pearls for the
cultured pearl industry.
Their Role in the Environment
Freshwater mussels serve as living
filters, straining bacteria,
phytoplankton and particulate organic
matter from the water. After passing
through their digestive tract, this
material is deposited onto the
substrate as feces. This is food for
other macroinvertebrates which, in
turn, are food for fishes. Periphyton
and algae grow on their shells which is
habitat for aquatic
macroinvertebrates. The burrowing
and movement of mussels through the
sediments remixes substrates,
stabilizing them and releases organic
matter to the water column.
Freshwater mussels, themselves, are
food for fishes like freshwater drum as
well as mammals like muskrats and
raccoons.
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Because they are long-lived and can't
move very far, they also serve as
indicators of water quality. They are
dependent on their environment for
long-term health in a way most
organisms are not because, if things
get bad, they can't pick up and move
somewhere else. It's simple:
Abundant, healthy mussels = water
quality is (and has been) good. Dead
mussels = water quality is (or has
been) bad.
Shell Anatomy
Freshwater mussels are bivalves
which means they have two opposing
valves. These valves are connected on
the dorsal edge with a hinge composed
of a ligament which holds the valves
together and hinge teeth which keep
the valves aligned. There are two sets
of teeth, the pseudocardinals and
the laterals. Between these two sets
of teeth is the umbo or beak. When
viewed from the side and imagining a
vertical line through the beak, mussel
