Weird coral formation??

[ErikG327]

I searched and searched and can’t find anything that looks like my mysterious hitchhiker. It’s a black and white coral-like formation on the base of my zoa frag. It’s starting to spread and growing up the side of one of the zoa polyps(first pic). Doesn’t seem to be harming it, but I want to know what it is before I pick it out of the tank. I thought it was a species of chiton or nudi at first, but it’s soft like a coral and doesn’t move. Any ideas?

 

[James M]

An you get a closer pic ?
Your zoas are also stretching for light

 

[DSC reef]

Looks like tunicates

 

[ErikG327]

An you get a closer pic ?
Your zoas are also stretching for light

I’ll get a better pic a little later when they open up a bit more. They have a tiny spike like a mouth in the centers.

 

[ErikG327]

An you get a closer pic ?
Your zoas are also stretching for light

Here are a few closer pics. In the first one you can see how it’s spreading from the frag plug across to the live rock.

 

[ErikG327]

Found this online. Star ascidian (Botryllus schlosseri) Looks very similar. Shouldn’t be concerned unless it gets out of control, right? What do you think?