I put 4 japonica shrimp in with my two rams....the rams lunged at them and they immediately became invisible. After about a week I saw one pink body. From that I assumed that they were all dead.
Worried that I had caused their deaths and mad at myself for making a dumb fish-keeping decision, I posted a similar question to yours here and folks responded with 'yes, rams will eat shrimps' and also 'shrimps are REALLY good at hiding.' After 4 weeks I still saw no sign so I figured I had learned a sad lesson at the expense of 4 little innocent lives. I felt really bad.
But then, all of a sudden, sitting on driftwood right in front of my eyes, there were 3 shrimps. They had been hiding! Big Time! The rams now ignore them totally.
My conclusion, though, is this: While I can see that these particular shrimps and these particular rams have reached an agreement, I think I'd think twice about putting shrimps (aka Food) in with cichlids again. I really hadn't thought about the shrimps from the point of view of the rams. (I do feed them shrimp pellets, duh.) I thought only that they were cute and small and interesting and useful and different.
I did put some shrimps in my 10 gal with little tetras, though, and everyone is happy.
My 2 cents.