Bivalves feed on plankton and nonliving organic matter.
Mussels are bivalve mollusks.
Mussels feed on plankton and nonliving organic matter.
What feeds on plankton and nonliving organic matter?

1. barnacles
2. mollusks
3. animals
4. the Sun
5. sharks
6. graptolites
7. bacteria
8. dogs