aiptasia or not?

Hi! I bought some live rock with pulsing zenia (hope I spelled it right). All the zenia died and a few days later I noticed a small growth that was sort mushroom like with short stubby tenacles. Over the past two years or so they spread around the rock and onto the sand maybe I have 25 or so now. They are dark greeish/maroon. They will change location, they close up sometimes into a small bubble and they catch food flakes on their tenacles and bring it too the center and eat it. Anyway, I've been trying to figure out what they are and the lady at the fish store said they are aiptasia and I should get rid of them but I like them and want to be sure they are bad. They haven't seemed to do any harm to anything in the couple years that I had them. The reason i think they are not aiptasia is because any photo I find of aptasia, they have long skinny tenacles, mine have short stubby tenacles. I have a few photos can someone finally positively id these things? Thanks!

 

I don't know if they are that either. Don't really look like it. Wouldn't either form of these harm other things. I have a fire shrimp that has walked all over them for the whole two years almost and nothing happens to him. In fact it looks like a game to him, he'll get on them and poke them one at a time with his legs and make them close up.

 

They look like the mushrooms I have in my tank. I think the lfs called them hairy green mushrooms. They are beautiful and love light. Here are pics of mine.

 

This is about the best one I could get, it's not really fully closed.

 

Those look like majano anemone's to me. They could sting other coral if its close to it. But its not going to kill everything in your tank. They are pest's because of the fact that they sting, and they can multiply and just about take over your tank. Your seem to be growing (splitting probably) slower than others, and I wouldnt take it out and kill it. They are pretty all together like that. Just make sure to keep it away from other coral, and if they start multiplying a lot faster than you could get rid of them.

 

this one I might try to save and see what it grows into. majano?

 

The way they look folding up, I would say Mushroom.

 

Thoes are shrooms.. Realy hairy ones at that.... heres a pic of mine i had... Polyps are simlilar .. and act the same ...






Mine when during feedin time would close up and look like a onion....


Good Luck....