Black spot on toadstool leather

[Formulator]

I’ve had this leather for almost 9 years and it has never had any problems. Everything else in the tank including another leather, soft, LPS, and SPS all look happy. Should I be concerned? Any idea what could cause this discoloration?

Salinity: 1.026
pH: 8-8.2
Alk: 9.5 dkh
Ca: 420 ppm
Mg: 1390 ppm
NO3: 7 ppm
PO4: 0.05 ppm

 

[MnFish1]

I’ve had this leather for almost 9 years and it has never had any problems. Everything else in the tank including another leather, soft, LPS, and SPS all look happy. Should I be concerned? Any idea what could cause this discoloration?

Salinity: 1.026
pH: 8-8.2
Alk: 9.5 dkh
Ca: 420 ppm
Mg: 1390 ppm
NO3: 7 ppm
PO4: 0.05 ppm

IMHO - yes - I would cut it out (BUT WAIT) - however - remembering if you cut a leather they can release toxins in the water. However - if that area is not changing - leave it. If it is spreading - cut it out IMHO. Curious - does your leather usually show its 'tentacles' they should be an inch or so long. Do you have the parameters in your tank? I would evaluate your tank parameters - try to fix whatever is going on.

 

[Formulator]

Its always been finicky. Never extended polyps a full inch. But like I said its 9 years old and has dropped babies. Anyways the black spot disappeared like 2 hours after I took the photo, so who knows what that was about.

Parameters are near perfect and very stable.

Alk: 9.4
Ca: 430 ppm
Mg: 1380 ppm
NO3: 10 ppm
PO4: 0.1 ppm
pH: 8-8.2
Tenp: 78.2-78.8

 

[DanyL]

I had this happen to a couple of frags I made, there were 40 medium-large sized frags and they were crammed together due to lack of space. Those that did not receive enough flow started to rot, and looked similarly to what you are experiencing here.

I dealt with it by simply cutting off that area, and placing them in a better flow, low light spot to heal.

Another option I've only read about (either here or over at reef central, it was years ago) is a parasite that bores into the base of leathers, and one of the signs was a rotting tissue.

Edit: We posted at the same time.
Sounds very odd, maybe it was just deflated in this area which only made that spot look darker than it really is?