(figure by Chris Todd)     (Click on the picture to get a live
photo of the various stages)  The reproduction of freshwater
mollusks from adult to an adult occurs in a variety of stages.
The first stage is the water column in which the sperm flows
with the water current until a female siphons the water,
collects the sperm and fertilizes her eggs.  After fertilization
takes place, it may take 1 to 10 months for the larva,
glochidia, to fully develop within the female. When the
glochidia are fully developed in early spring or fall, they are
released into the water where they drift until they find a
suitable fish host. Unionaceans are divided into two distinct
behavioral groups depending on when the female disperses the
glochidia, bradytictic or tachytictic (Watters 1995).
 Bradytictic (long term breeders) hold their larvae throughout
the winter until the following spring or summer (Watters 1995).
 The tachytictic (short term breeders) release the larvae later
the same year, usually by July or August (Watters 19