Please help

[spud71]

I woke up this morning to find my coral looking like that below. It has always seemed healthy and I have had it for several months no problems. Is this crab eating it?

http://reefcentral.com/gallery/data/500/104868IMG_0427.jpg


I also have staghorn coral, acropora, two clams, mushroom corals and candy cane coral and hammer coral, all doing great.

The water parameters are fine, no measurable nitrite, nitrate or ammonia. Ph is 8.05 (using neptune sys lab grade probe, measures 8.2 with test kit), Calcium is 480ppm, Alkalinity is 3.2 meq/l (salifert tests)

Water temperature is maintained with a neptune jr system at the current annual reef temperature mode (currently about 79 degrees) +- 0.5 degrees (chiller and twin heater).

I have two 96w PC, two 175 W MH.

Tank is 50 gallons, sump is 10.

In addition I have many of the usual snails and hermits, along with two percula clowns, I royal gramma and a twin spot gobby.

Is this a disease or is something eating it? All the inhabitants have been in there for a while except for the twin spot that is fairly new. Is he the culprit perhaps? Please help if you know what I should do. If this is the wrong place to post please feel free to let me know where I should post it.

:(

Simon

[Underwaterparadise]

Did it have any damaged tissue at all before this happened

[spud71]

I am not an expert with this type of coral, this being my first, but it appeared to be healthy to me, the mouths would open and appeared to eat. Then this morning it looked like half the thing had been eaten or something.

I dont know whether it is dead or not or whether to take it out of the tank.

Thanks

[gflat65]

Kinda looks like just the center section is dead... That is a brain, right (several Crown and Cokes into the night and the shot isn't the clearest;). If the rest has tissue expanding and you have a dead spot, i'd have to question if anything fell into the brain and stung it. If calcium or alk buffer were added directly to the tank or salt from salt creep were to land on it, it might cause tissue necrosis.

[Bcollins111900]

It does not look good at all. I would try to dip it in coral dip and see if that will help stop the recession. Try moving it to a shady spot. It is 50/50 it will make it. If it happened overnight something had to either sting it or irritate it to the point it shed it tissue.