Rapid Tissue Necrosis

[spanko]

For those of you that do not keep SPS coral and even those of you that do here is a time lapse video of a RTN event. Notice that not all of the SPS are doing it just two by the video. It seems to go this way, some will RTN while others in the same tank and proximity will flourish.
http://www.youtube.com/watch?v=t2xjht42lrI

 

[florida joe]

Good Visual Henry may I add that one needs to make sure before deposing of their coral that it is in fact RTN and not bleaching

 

[spanko]

Good point Joe.

 

[truperc]

Pardon the ignorance, but how do you tell?

 

[truperc]

Anyone?

 

[spanko]

In a RTN event you will see the colorful tissue actually slough off like in the video. Bleaching you will only see the color of the coral turning to white. Most often you will still be able to see some polyps even in the whiteness.

 

[jackri]

I've had it happen recently to one of my larger corals... fragged and refragged and have about 20 frags left that survived.
Anyone know what causes this?

 

[jetskiking]

Originally Posted by jackri
http:///forum/post/3123746
I've had it happen recently to one of my larger corals... fragged and refragged and have about 20 frags left that survived.
Anyone know what causes this?
No, the only thing you can usually do is frag the uneffected parts before the whole thing goes.

 

[spanko]

I have read about and experienced RTN after an extreme change in temperature. However there are other causes. Trauma, low alk.

 

[jackri]

I'll have to recheck my alk tomorrow... but everything else healthy and normal but I didn't get a chance to check alk today.. was calcium OR alk with the time I had and went with the calcium. Hmmm

 

[truperc]

And as I understand it, RTN will always lead to death of the coral, and bleaching may or may not lead to death.
Is that accurate?

 

[wangotango]

Originally Posted by TruPerc
http:///forum/post/3124144
And as I understand it, RTN will always lead to death of the coral, and bleaching may or may not lead to death.
Is that accurate?
Pretty much. With RTN the tissue essentially "melts" away leaving just the skeleton. A bleached coral still has tissue but loses its zoanthellae. A bleached coral can recover, it just takes time and very good water quality.
-Justin