RTN on acropora tortuosa

[Punchanello]

or at least, I think it is tortuosa. It's a white with blue tip variety, very similar to this -

...This happened literally overnight:

My alk has been stableish for the last month at 8.0 to 8.2. No spikes or anything like that. My calcium and magnesium are a little low though (410 and 1310). No other corals appear affected.

The only thing I can think of is that it is in a very high flow area coming in from the side that is receding. Only a nearby Millie is exposed to more flow. The Millie has been fine. Perhaps the tortuosa is less suited to the flow?

Grateful for your thoughts.

 

[Graffiti Spot]

Oh wow, if you got a piece of that one pictured I am very interested in where you got it? Could you share with us? Was the piece a new coral addition or had you had it for a while? That tort I remember seeing a write up on and it was everywhere in this one reef but it was in a place where no one could collect. The white with light blue is the nicest tort coloration in my opinion.

 

[jda]

It is hard to judge flow over the internet. You can have too much direct flow that can peel tissue off of a skeleton. If you suspect this, then move it.

 

[Graffiti Spot]

Looks like it's a new piece that's stressed from shipping and starting to peel.
Flow normally doesn't make a healthy acro peel unless it's very directional and the flow is hitting it dead on, before it disperses in the water some.

 

[markalot]

How old is the tank?

How long has this acro been in the tank?

Has Alk ever gone near or above 9 while this coral was in the tank and if so when? Keep in mind acros can take sometimes take weeks to show damage so it's something that happened weeks ago, possibly even a month. Also keep in mind different acros respond differently to stress. I could not keep an acro that looked like this alive, died overnight after looking good for a few weeks.

I learned to toss and move on rather than react, but it's still worthwhile going through everything that's happened in the tank while the coral was in there to try and find the issue.

 

[Punchanello]

So it's been in my tank for a month. I moved it 2 weeks ago as I wss aclimating it at lower light. Wild colony and honestly, tortuosa was the closest ID I could find but still unsure. Alk has never been near 9. Tank has been up 9 months.

I'll move it again in to less flow. Should I frag the receding branch?

 

[Big E]

Both those pics look like bleached corals to me. A coral that is bleached for a long time like that will eventually show RTN one morning when the lights come on.

If I get a coral that is that pale the first thing I do is put it in a place with indirect light so it can get some zoo back.

Pics #2 and 3 are much better and look how the coral should look when not pale/bleached in an aquarium or in nature.

https://reefbuilders.com/2014/04/10/acropora-tortuosa-kwajalein-unique-blue-tip-color/

 

[Graffiti Spot]

You could cut the tissue necrosis off where the flesh is healthy. Or if it stopped moving down the branch leave it and let it heal and cut the old skeleton off later. Or if it's still dying you could try to superglue the areas where it's peeling.
Also bigE has it right, putting it in low light would help it recover.

 

[Punchanello]

Both those pics look like bleached corals to me. A coral that is bleached for a long time like that will eventually show RTN one morning when the lights come on.

If I get a coral that is that pale the first thing I do is put it in a place with indirect light so it can get some zoo back.

Pics #2 and 3 are much better and look how the coral should look when not pale/bleached in an aquarium or in nature.

https://reefbuilders.com/2014/04/10/acropora-tortuosa-kwajalein-unique-blue-tip-color/

Interesting take on the bleaching. I'll try to report back if I can get it back to a healthy state to show it's true colour.

For now the recession seems to have stopped. I'll move it lower in the tank and away from direct flow.

 

[jda]

If that is truly a Marshall Island coral, then it will need ULNS to have the best colors. The waters around the Marshalls are probably .01 nitrate and .005 phosphate with no food for them to catch and thus very low PE on most of these corals. This coral might need a ZeoVit, or the like, to look like the one in the Reef Builders photo. In any case, this is for a later time and not until it recovers.

 

[Punchanello]

If that is truly a Marshall Island coral, then it will need ULNS to have the best colors. The waters around the Marshalls are probably .01 nitrate and .005 phosphate with no food for them to catch and thus very low PE on most of these corals. This coral might need a ZeoVit, or the like, to look like the one in the Reef Builders photo. In any case, this is for a later time and not until it recovers.

I doubt this is a Marshall Island coral albeit it looks very similar to the one in the picture. The vast majority of corals we have access to in Australia are wild colonies and I'd guess that next to zero (or indeed zero) are imported. I can see polyps but you are correct, there's next to no extension.

Would you hazard a guess JDA as to whether this is a deep water coral?