Weird lump on Red Planet bursts...

[JSeymour]

So at the end of last month, I noticed a odd growth tip on my Red Planet(RP) Acro. It wasn't too odd and the coral seemed healthy so I didn't think anything of it.

Taken 5-30 with halides on, no flash.

This tip turned into a lump, but the coral still seemed fine, so once again I thought nothing.

Taken 6-19 with halides on, no flash.

After an unsucessful red bug dip on a new coral, I discovered a few on a unknown deepwater acro. So I treated with interceptor on 6-21. This morning, 6-23, when the actinics kicked on, I noticed the lump had burst and was completely hollow, coral still seems fine, although stressed in that area.

Taken on 6-23 with halides off, with flash.

My best guess is some sort of gall crab maybe, and the interceptor killed it? What do you think?

 

[curlykid]

a similar thing happened to my green slimer a while ago. since it was at the tip of a small frag, it caused a growth pattern similar to a tree, which caused the main branch to turn pale. it looks really weird.

 

[mike810]

Looks like alk burn or some tissue recession that has started to heal over. I had alk burns on a colony that have since regrew over the dead tips and it grew into big bumps/lumps

 

[JSeymour]

I never noticed any burnt tips, but you could be right. This lump is hollow, like a bubble, as if the coral grew around something. I figured it was some sort of crustacean that was possibly, recently introduced(a long story in it's self) and died during the interceptor treatment. The dead body could cause localized acidification causing the skeleton to "burst"/crumble. I don't think there is a problem, I was just kind of curious about it.

 

[garlicbred]

It could be a gall crab?