HELP! Pinch mantle ID please

[Samdwichote]

Hi
I recently bought 3 clams about 12 days ago they seem to be doing well but one here is a picture from past Friday

But then since past Sunday one began to retract a small part of the mouth area mantle and the one that doesn't seemed happy still looks the same, i started to think that this could be pinch mantle but I need help to confirm it is so I take them to FW dip, I really don't want to lose any of them since it's pretty hard to get them here.

This one was opening pretty good since it arrived but now it's like this

This one looks like this since day one, it was fully covered of aptasias I thought I was just irritated, cleaned it but has been like this forever I'm starting to think its pinch mantle

And this is the third it seems to be okay along with the small first clam I introduced long ago

 

[OrionN]

Something irritated you clam, but I do not think that it is PMD. PMD start out with only one small part of the mantel, no the whole side of mantel like what you have.
Enclosed is the the very first documented picture of PMD documented by myself in 2002. The B&W clam is normal and the and the blue Max with PMD. The Green Crocea is normal.
Look for other cause as problem for your clams

 

[OrionN]

For historical interest, this thread from reefs.org have the distinction of been the first ever mention of PMD ever anywhere

http://www.reefs.org/forums/viewtopic.php?p=169654#169654

 

[Samdwichote]

Thanks a lot OrionN I'm testing but my parameters are fine I'll inspect for pyramid snails later today, let me check the link you provided