Well, I am fairly certain I have found the problem. While taking top-down pics, I got a series of shots like this:
The clams started having the problems after I introduced these cleaner wrasses... I watch him come up and nip at this clam several times in the space of about 10 minutes.
As far as the green goes, I think its actually algae. So now I guess I have to trap the wrasses and it ain't going to be easy!
I really appreciate your help, and of course encouraging me to take the pics led me to the problem.
