clam with a "pinched" mantle

[organicreefer]

i started a collection of clams ,one of them ,a 4.5" or so deresa,has a couple of pinches in his mantle,as though someone had sewn a single stitch in two places at the edge.
ive had the clam about a month.
the first one showed up a week or so ago and now today i see a second.
any ideas?i guess i should look for snails or something??
i really dont want to move him but i guess i have to?

 

[toptank]

A picture would be very helpful

 

[simonh]

I would check for snails on a night with a flash light. See if you can seen any on the upper rim of the shell feeding on the mantle.

 

[organicreefer]

ok there are some snails on the shells-but they are tiny rounded ones ive always had in my tank -the same ones are on the glass /rocksas well as all my clams.
i dont see any "pyrramylid" snails(or however you spell it.)
are they hard to spot?i looked two nights in a row i dont see any.
im really concerned about the rest of my collection
im attaching a pic of the pinched spots -its not very clear but i think you can see it.

 

[organicreefer]

oops that was the wrong pic here a closer shot

 

[adamgrandprix]

uh... is that pic completely out of focus or do I need to update my lens prescription? A clearer pic would help immensely... maybe not so close if it won't focus... a clear pic farther away would be better than a blurry close-up.

 

[organicreefer]

yeah i stated above the pic sux
i still cannot find what the source of the irritation is/was.but
anyway, the deresa seems to be "getting better" on his own