Acro issue

[Yash]

I am new to SPS and have no idea what is eating away at one of my acro frags.

I noticed something eating away at one of my acro stalk tissues. In the picture below in the bottom left of the stick in the background you can see an area being eaten away. At the damaged area I can see some really fine filaments - almost looking like an aptasia filaments, just super thin. I also think I see a small hole at the center of the damage. The polyps on the entire edge of the stalk where the damage is taking place have receded/disappeared.

Any idea what this could be and what I need to do to address the issue. All the other corals don't seem affected at this point. The rest of the acro looks fine with no bleaching and good polyp extension. Please ignore the piece of food floating around. The photo was taken after I had fed the tank.

My first thought was AEFW but I have yet to find the first flat worm in my tank.

Thanks in advance for your help!

 

[markalot]

Are you sure it's not encrusting? Some acros will put out a bunch of filaments on the edge to clear a path to encrust.

 

[Yash]

Are you sure it's not encrusting? Some acros will put out a bunch of filaments on the edge to clear a path to encrust.

Honestly, I don't know. This is my first acro so everything about them is new to me. I will keep and eye on it over the next few days to see how it does.

I will be beyond thrilled if this is all just a growth spurt!