How do mussels reproduce?
The life cycle of the freshwater mussel is one the most complex and
interesting in the animal world. Unlike other animals that can actively search
for a mate, the sedentary mussel depends on the river current to reproduce. The
process begins with the male releasing sperm, and the female located downstream
drawing it in through her incurrent siphon. Numbering in the 100's to hundreds
of thousands, the fertilized eggs develop into glochidia within her gills. Once
mature, they are released into the water column to begin the second part of
their lives-attaching to the gills, fins, or scales of freshwater fishes. At
this point, the process is further complicated because not only do the
glochidia have to find a fish, but it has to be one of a few specific fish species
for the life cycle to continue. If a glochidium attaches to the correct fish
species, it encysts into the fish's tissue and undergoes a short life as a
parasite.
Over several weeks, it begins to develop gills, a foot, and other
internal structures to become a juvenile mussel. The now fully transformed, but
still microscopic, juvenile will drop off the fish and begin its life on the
stream bottom. Unbeknownst to the fish, it has just served as a taxi
transporting the young mussel into new habitat away from its' parent. If the
mussel is lucky enough to grow into an adult, it may live 20-100 years or more
depending on the specie
