Tasty Tubastrea vs Killer Chromis

[davidc]

My sun coral used to be so happy...it would come out during the day, or anytime I wanted to feed it!

Then I got 4 chromis. 2 are really big for chromis. They court by 'kissing' each other occasionally. The other 2 are very small.

The big chromis will peck at the sun coral when it is closed, and a small orange ball of something pops out. The chromis apparently LOVE how it tastes, so they are obsessed with harassing every single polyp on my sun coral and eating the 'treat'. It's gotten so bad, so constant, that it hardly comes out to feed anymore. When it does come out, it seems the polyps are smaller than they used to be.

I tried chasing them away, but they never gave up. What's cool is my yellow tang has apparently 'learned' that I don't want the chromis pecking the sun coral. He would chase them away about 75% of the time. That isn't enough to stop them though. I finally removed the little monsters so I can start feeding my sun coral again.

Questions:
Has anyone seen this kind of behavior before?
What exactly are the polyps spitting out that the chromis think is so tasty?
Are there any other fish I should expect to do this?

[Kent E.]

I never heard of this before maybe the coral is releasing gamets? I know that these corals usually don't do very well unless you have the branching form.

[davidc]

Originally Posted by Kent Emirbayer

I never heard of this before maybe the coral is releasing gamets? I know that these corals usually don't do very well unless you have the branching form.

It was doing great before the chromis - it was growing new polyps.
It's doing better now without the chromis, but still hasn't completely recovered.

It's releasing a solid orange ball about 2-3mm in diameter. I don't think it's gametes, and it can't be zooxanthellae - tubastrea doesn't have that.

EDIT: in fact, my avatar is a pre-chromis pic