open brain colour/ zoo?

[outtafocus]

I have a red open brain coral, which up until the other day was always a nice deep constant red.
The other day, a portion of it became an almost flourescent pink. It is still eating as before and has lost no visible size.
The following pic makes the coral look sickly, but the real thing looks better.
What do you feel could cause a minor colour variation?
I have changed nothing during this time, except the standard 10% bi-weekly water change, and no lighting changes either.

Once possible thing could be from a nearby coral, I believe this coral is a galaxia. It may be close enough to reach out and touch the brain, but I have never witnessed it do this, I have seen it reach out though.
These two corals have been neighbors for 4months. The "galaxia" is visible just behind the brain.


Also, all of the zoo colonies I have dont seem to grow, they open fully most of the time and seem in good health, just never increase in size.
I had one small frag of green zoos (10 polyps) which just seemed to slowly disapear to nothing. I checked all frags for and nudi's or snails and no sign. Any tips to make them pop?

[DanG]

galaxia=the bully coral. It could very well have stung the brain.

[SeaHorse_Fanatic]

Galaxia are among the most aggressive & harshest of the corals in terms of their sting. Their attack tentacles can grow to up over 8".

Anthony

[Delphinus]

Hmmm, that's odd. I wouldn't discount the galaxy but the thing is if the brain had gotten stung, it's not likely to expand the tissue in the affected area (i.e., more likely it would pull in tight). But the tissue does look a little bleached, so something's up. It could be that it just shed some zooxanthellae, which does happen (and isn't necessarily fatal unless it's a bad stress response, but sometimes it just happens -- usually in response to a change in light intensity or maybe even a temperature swing - in those cases, if all other things are good then it should be able to recover.)

[SeaHorse_Fanatic]

True. Actually, I found that my red corals (brains/donuts) faded when placed high up & near the lights. I don't think the galaxy is the source of the fading, but it may be a source of concern for his other corals in general.

Anthony