Is this algea or sponge?

Didn't know where to post this as I don't see a IDENTIFICATION PAGE so I'll try here. My guess is this is an algae. It is growing on my x-mas tree rock. It started out about 1/8 inch in size and has pretty much doubled in about 9 days. Though the pic doesn't really show it, it is semi-transparent. Thanks.

 

Defenatily not algae. Probebly some kind of sponge... but not algae for sure

Marc.

 

It doesn't look like a algae and definitely not a sponge. I have a few sponges, and the structure of the body doesn't look like one. Maybe a coral, keep us updated with pictures as it grows.

 

It looks like it was polished. Does it have a shine to it?

 

Whatever it is has a really nice look to it- cograts on the freeby!

 

I can't find anything as far as pics go to identify it, but I think it is an algea, possibly bubble form or possibly Scinaia sp.? Maybe Porphyra sp.? I don't know much about algae.
Anyway, yes it does have a shine to it. I was going to trade the x-mas rock that it is attatched to for some rics with a friend, but I think I am going to wait and see what it grows into and if it might spread.
I'll get pics posted as it progresses.
A coral Reef Lover? That would be awsome! I'll observe it at night time. I suppose if it were a coral it would give some indication, maybe deflation, with photoperiod cycle.
Thanks all.

 

If its shiny then it definitely not a sponge. When leather corals molt, they going into different phases and one phase is, it looks waxy and has a shine to it. It might be some kind of soft coral.

 

apollo

It is a red algae Predaea weldii or similar species

SeaweedAfrica

 

Whatever it is it sure looks cool

 

Thats a pretty cool looking freebee, if it keeps growin keep them pics commin.