It might be the acan echinata. I have different acan lords touching with no problem, but an acan echinata I got rid of would try to digest anything near it by putting out mesenterial filaments. This was my purple echinata attacking a brain. It did the same to a toadstool and anything else too close to it:
Amazing pic!!! They were about 4 inches apart, and now nothing is within 6" of the echinata. Seemed to work at first but now I am not so sure.
Have you had any other LPS showing signs of tissue recession? That coral is pretty far gone but I'd probably try to give it a dip. I had something start on a small acan colony I ordered that traveled to most of my LPS in the tank wiping out a massive colony of duncans I had and did it very quickly. Not quite as fast as brown jelly. Once it started on my favias I pulled all my LPS and did a dip and it stopped the infection. Not saying its going to happen in your tank but I'd keep an on it.
My guess is the tissue was nicked during the fragging process. It looks very far gone but it does still have a polyp with a mouth so dipping it may save it. If you do , turn off all the powerheads and lift the coral very slowly and gently to make sure the tissue isn't further pulled away from the skeleton. Good luck!
The echinata seems pretty fine. the fleshy part of him is spread over the stony part of the frag, so that sounds good, right? His colors are still good. I will be paying very close attention. He seemed fine in the store but i do not understand why the polyp is not fully round, the nicking sounds good. plus i think the store had really good conditions. Here is a pic of a few days after I got him:
Not a good depth of field for this but he is a little puffy. He got this way for a few hours a day for 2-3 days, but yesterday he started looking the same way in the first pic.
What should I dip it in??
Thanks for the help everyone!
Jay