Mollusca Ecology

Question
I'm studying phylum mollusca and I went to google to search for 'Mollusks: sybitotic relationships with other organisms'
But I couldn'g find anything helpful. Or anything I could actually understand.
Can you help me?

Answer
I'm afraid it's out of my range.  You'll be hard pressed to find much information about mollusks (snails, clams, etc.) on the internet or anywhere else.  Clams and mussels use fish as hosts for their early life stage.  They are parasitic as baby clams living in the gills of fish.  It's not really symbiotic as the fish don't get anything out of it!  Also, there are many parasites of clams that also then parasitize other animals. Again, not symbiotic.  So, nothing helpful comes to mind.  Sorry.