Back from vacation and saw this.

[otoklucu]

Looking for some advice on my clam. I just got back from a two-week vacation and noticed this. My water parameters are all great and stable. The clam is fully expanded except for these two areas on opposite sides of the mantle.

Any idea what could be causing this? Should I be concerned?

 

[lowsreef]

This appears to be pinched mantle syndrome, if you run GFO that is likely the culprit.
I’ve found Keeping clams in GFO tanks is a losing endeavour as they generally all begin to exhibit signs of PMS.
Could also be pyramid snails or nipping from curious fish, other stressors or nothing at all.
lol, not much help huh?
Do some reading on PMS and treat accordingly if that’s what you suspect as well.

 

[minus9]

It's hard to say, especially when we can't clearly see what's going on. Use a filter or change to a daylight spectrum when taking pics, blue pics are kinda worthless when looking for details. There could be something irritating the mantle or something else. I would monitor for a couple days and see if it progresses.