polyps regressing

[acasden]

My 75 has been rock stable for 3 yrs, a colony of zooanthids has done well over the years covering almost an entire rock, over the last 2 months it is slowly regressing (dying) down the rock in even progression, not haphazard as I would expect if a fish were picking on them.. any ideas ???

also a copperband that is doing well has a dark thing on the tip of a side fin, not sure what it is???

 

[ChrisRD]

Have you added any new livestock in the past few months or made any changes to the system? How old are your lamps? What are your current water parameters?

 

[Charlesr1958]

How long has the copperband been in the tank? I have had them go for a few months with no issues only to notice that my zoanthids were always remaining closed and caught the butterfly in the act of nipping at their tentacles. The butterfly is now back in the ocean. Besides what has already been asked / suggested, you may have a predator such as a crab or even a uenicid worm at work during the night. Might want to shine that rock a few times a night when all is dark and see if you can catch something in the act.

Fish Disease Identification Guide

Chuck

 

[Chubosco]

My money is on the lighting. If it is, others will follow suit shortly. Had that problem earlier this year.

 

[Anonymous]

I also vote for checking the lighting.

 

[acasden]

thanks for all the replies, my question is can lighting affect one coral and not the others?? all the other corals in the tank look fine. I did add a flame angel (yes I know it can harm some coral) and a copperband because of some aptasia but all else is fine, no change in water parameters, have checked at night and no predators.

Thinking back, I used some Joe's juice on some aptasia that was growing among the poylps, some may have hit a few polyps close by, could harming a few lead to the death of the whole coral?? are they separate or connected in some way???