Behavior:
Reproduction requires a stable, undisturbed habitat and a sufficient
population of host fish to complete the mussel's larval development.
When the male discharges sperm into the current, females downstream
siphon in the sperm in order to fertilize their eggs, which they store
in their gill pouches until the larvae hatch. The females then expel
the larvae. Those larvae that manage to attach themselves to the gills
of a host fish by means of tiny clasping valves, grow into juveniles
with shells of their own. At that point they detach from the host fish
and settle into the streambed, ready for a long (possibly up to 50 years)
life as an adult mussel.
Why
It's Endangered: Reasons for this mussel's decline are not fully
known, but throughout all the drainages from which it is now absent,
habitat has been severely altered or destroyed. Impacts include dams
for power and navigation, siltation from agricultural run-off, chemical
pollution from agricultural pesticides and industrial wastes, and effluent
from strip-mining and coal-washing operations.
An added
threat is now the zebra mussel, a fast-spreading exotic (non-native)
species from the Caspian Sea area. These tiny mussels reproduce in enormous
numbers which tend to cover and suffocate native mussels. They also
often outcompete native mussels for food.
E-Mail
Us!
Phone: 612/713-5360
V/TTY: 800-657-3775
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Region
3 Endangered Species Home Page
National Endangered Species Home
Page
Region 3 Home Page USFWS Home Page
U.S.
Fish and Wildlife Service
Division of Endangered Species
BHW Federal Building
1 Federal Drive
Fort Snelling, Minnesota 55111-4056
