Native mussels need fairly cool water or you'll have a mass die off.
You could try a few at first and see how they do. If they die you won't
have too big a mess to clean up.
Mussels need fish to breed. They send their new hatchlings out to
live in the gills of fish. Doesn't hurt the fish but some mussels need
a specific breed of fish to brood their eggs (not the best planning if you
ask me). Clams don't have this breeding problem, but you still have to watch
the water temperature with clams also.
Crayfish nip at fish, eat young and sick ones, same with tadpoles and
try and pry open mussels.
That said I would love to have a large lotus bog and I would add those
critters, and turtles and salamanders/newts and invite predators to drop in...
a whole wildlife buffet - what a show!

Good luck and let us know how it goes!
k30a