Leather coral pest or disease

[mattschwind]

I've had this mixed reef tank for over three years, all fish and corals look great except for my leather corals (devils hand and toadstool). Keep in mind this pictures are taken at night, there is some polyp extension during the day and it does color up a bit. This started a few weeks ago and I've had the corals for two years.

There is notable damage to the coral as if something has been feeding on it, however I can't observe any pests during the day or night time. Any ideas what it could be based on the damage? Any recommendations on how to check for pests? Should I pull the coral out and dip it and assume it's a type of flatworm that's impossible to see with the naked eye? Any suggestions are appreciated!

 

[kharmaguru]

Devil's hand are pretty rugged corals. Is there any nearby corals that could send out sweepers at night and sting it? For example if that little coral under the arm was a hollywood stunner in would sting it every night.

 

[mattschwind]

Devil's hand are pretty rugged corals. Is there any nearby corals that could send out sweepers at night and sting it? For example if that little coral under the arm was a hollywood stunner in would sting it every night.

I appreciate that thought, I only added that frag a week ago after the coral has been damaged for some time and there's no other corals for a good distance from the devils hand, so I don't think it's coral warfare. That being said, I can find a better place for the frag so that doesn't become a problem.

Some of the damage looks similar to what the coral looks like when it "drops a finger" and reproduces, but im just not sure.

 

[kfisc]

Nudibranchs?

 

[mattschwind]

Nudibranchs?

That's my next best guess. I've found one or two that may have came in from some live rock I added. Time frame fits as well. No idea how to trap or treat for them as I have some berghias in there for the aiptasia I want to keep alive. I'll ponder that! Maybe I'll take the leathers out in a quarantine tank for a bit and if there are leather eating nudibranchs in the display they will die off.

Also Merry Christmas!

 

[kfisc]

You as well!