Does this appear to be AEFW?

[FireWorm123]

 

[KrisReef]

Maybe?

The series of bite lines look more like a tooth bite (Wrasse or parrot fish removing chucks of skeleton and flesh) than a flatworm bite. The missing area of receding flesh could be from aefw or tissue necrosis (fast or slow) and the black line looks like a bacterial infection (black line disease?)

Or maybe just black film microbes growing on the naked skeleton?

It's different. The rock in the foreground also looks like a parrot fish has been biting it. Do you have a parrot fish in this tank?

 

[Sisterlimonpot]

Based on those pictures, I don't see the telltale signs of aefw. Normally you'd see patches of little white (exposed skeleton) dots surrounded by somewhat healthy tissue.

If I were to base an assumption solely on those pictures, my 1st thought would be necrosis from something entirely different than aefw's.

More data would help, how old is the tank, what livestock do you have? And have you made any major changes to the balance lately?

 

[Miami Reef]

I agree. It doesn’t look like AEFW damage to me.

 

[FireWorm123]

Based on those pictures, I don't see the telltale signs of aefw. Normally you'd see patches of little white (exposed skeleton) dots surrounded by somewhat healthy tissue.

If I were to base an assumption solely on those pictures, my 1st thought would be necrosis from something entirely different than aefw's.

More data would help, how old is the tank, what livestock do you have? And have you made any major changes to the balance lately?

Thanks for your reply,

Tank is 1.5 years old, i have a purple tang, foxface, Sixline wrasse, 2 clownfish and a yellow goby. I believe i have vermetid snails somewhere in the tank…

Only parameter fluctuation was a week ago, alkalinity DKH randomly went from 8.7~ to 7.2~, and PH from 8.15 to 7.8. Parameters have been consistent except for that.

No major livestock changes for a long time.

 

[KrisReef]

Seems likely that the alk swing triggered RTN, not uncommon but not well understood (by me, anyway.)

If it continues to lose tissue, fragging off a healthy tip far away from the recession line may save a frag of an otherwise likely doomed coral.