Blue coraline

[Echidna09]

Is blue coraline rare? Everyone always talks about the purple stuff but I am starting to see small patches of blue in my nano-reef (which refuses to grow coraline where direct light hits >.<), and I found some on some fake decorations in one of the tanks at work (actually a customer pointed it out, which I responded with "that's a fake rock", then after looking at it closer noticed that it was in fact not part of the rock). Anyway I just think it's pretty cool stuff and wondered why it never really gets mentioned.

 

[Red Firefish]

I have never seen or heard of blue coralline algae. So, if what you have is indeed blue coralline, I imagine it is quite uncommon. However, since you mention that it's not growing in direct light, I'm more inclined to think that it's sponge. Many cnidarians are blue, such as sponges or tunicates. Could this be what you have? Could you post pictures of it?

 

[Echidna09]

Actually the Blue coralline is getting is getting hit by direct light. I have purple too, but 90% of it is in shaded areas. I can try to get a picture of it. I don't think I will be able to get a clear enough one to see it because my camera doesn't have a great macro mode, but I will try. I doubt it is a sponge or tunicate. It is flat and in various places. Resembles some orange coralline that I have in my 55 only a different color.