Is this the start of PM?

[JoeESSA]

A few days ago I noticed that my Maxima? clam appeared to have lost some tissue at the edge of its mantle in a couple of areas. I assumed that maybe something in the tank was nibbling at the clam, but then I read about pinched mantel disease on this site.

The picture is very poor quality, but I have circled the areas that appear affected. The one to the top of the picture is about 3/4" long and appears that the edge of the mantel is "nibbled" off. The blue border of the clam is gone at that point giving the appearance of missing tissue. When the clam retracts this areas draws in noticeably further and is also last area to extend when mantel extends. The other two areas are small notches.

Any ideas?

 

[JoeESSA]

This picture is better

And here are the other two clams in my tank. I am assuming that they are OK. I never paid attention to the folded edged of the mantle until reading the Reef Keeping PM article.

and

 

[OrionN]

I had a small goby that took chunks off of my clams before. It looks like a semicircle of tissue missing from the clam mantle. This may be what's going on in your tank. IME, PM does not look like this. In PM, the tissue is not missing, rather, it is retracted and fold where the mantle is diseased.

 

[jmaneyapanda]

that just looks like mechanical damage to me.

 

[JoeESSA]

Thanks for the replies. I guess you are agreeing with my initial suspicion, that something is having a go at the clam whatever that may be...Two days ago the clam only had the upper area of damage and one notch lower down on the left hand side. Yesterday when I took the photos another notch had appeared on the left hand side. I know that my maroon clown hovers above the clam a lot and she has a tendency to bite things that she suddenly decides are within her territory...

 

[Serioussnaps]

your clam looks fine IMO