Monti stung by torch or something else?

[Pau Hana Reefer]

I noticed a black spot on my Fire Digitata Montipora last night that wasn’t on it the day before. I’m suspecting that my torch coral stung it and hoping someone can help confirm.

The closest tips of the Aussie torch coral are 6-7 inches away. The last time I saw the sweeper tentacles was a year ago when it was smaller and a single head, so I have no idea how long they are now. The black spot hasn’t changed in size over the last 24 hours.

Or am I way off and this is something else?

 

[Boxofpurplerocks]

To me it looks like an area of tissue necrosis that now has algae growth on the skeleton. I doubt a torch would cause that...one of my torches occasionally brushes a miyagi tort colony I have next it and haven’t seen any negative impacts yet.

 

[Pau Hana Reefer]

To me it looks like an area of tissue necrosis that now has algae growth on the skeleton. I doubt a torch would cause that...one of my torches occasionally brushes a miyagi tort colony I have next it and haven’t seen any negative impacts yet.

Thanks for the feedback. The algae growth (Bubble algae) is actually 1-2” behind the monti on the rocks. I looked a little into tissue necrosis and still need to look more into it. But seems tissue necrosis could be caused different factors? At least one thread recommended cutting away the black spot to save the coral. Others said to observe. Any thoughts for my coral?

 

[Boxofpurplerocks]

Thanks for the feedback. The algae growth (Bubble algae) is actually 1-2” behind the monti on the rocks. I looked a little into tissue necrosis and still need to look more into it. But seems tissue necrosis could be caused different factors? At least one thread recommended cutting away the black spot to save the coral. Others said to observe. Any thoughts for my coral?

What I was referencing was what I thought was algae growth on the skeleton. When tissue necrosis occurs, you will only see white skeleton for a short amount of time before algae grows on it (~1 day) which will change the color. That’s what it looks to me like happened here. In terms of what to do, you could either frag the top half or let it be, both would have a decent chance at survival. Finding the root cause is the important factor here

 

[Pau Hana Reefer]

What I was referencing was what I thought was algae growth on the skeleton. When tissue necrosis occurs, you will only see white skeleton for a short amount of time before algae grows on it (~1 day) which will change the color. That’s what it looks to me like happened here. In terms of what to do, you could either frag the top half or let it be, both would have a decent chance at survival. Finding the root cause is the important factor here

Got it, thanks for clarifying.

I think I’m going to try leaving it be. I’m assuming I should frag the top half if the monti for any reason it starts to look progressively worse?

Any thoughts on causes that I can look into? My last parameters were taken 4 days ago and I can take them again this afternoon if it helps with identifying the root cause. I also switch salts from Reef crystal to Tropic Marin Pro the day before noticing this spot. I don’t see this on any of my other montis.