I have had a piece of live rock for many months (probably @ 7). Several sponges have been growing on it and a little xenia has attached itself at the bottom. Yesterday I noticed that another little sponge is popping up near the others but also there is a dark red ruffly looking growth coming from 2 separate places. I've looked it up and the only thing I could come up with that looks similar is halymenia. The info that I'm reading says that halymenia is usually free floating. It is fleshy... not hard and is still quite small or I would photograph it. It is in a tank in which there are no corals- except the xenia and some athellia. Nothing new has been added in several months except a few pieces of dead rock. I only have 2 clownfish, a watchman goby, a pistil shrimp, fire shrimp, 2 peppermint shrimp, hermit crabs & snails... and a sea urchin. I did actually add the sea urchin @ 10 days ago. But he was out of my other tank and I have nothing in there that looks like this. If you have any ideas of what this might be please let me know. I am trying to find pics for comparison since I can't get a good pic at this time. Thanks for your help.