What is this?

I just noticed this today. It's on the bottom of my center rock. It kind of looks soft, almost like a white mushroom or something. I don't ever remember seeing anything like it in the tank before.


Sorry, the pic is not the best, but it's in a really awkward spot to try and get a decent photo of it.

 

The white part is def. soft. I stuck my kent scraper down there and moved the water around a bit and it moved back and forth a little. It also looks like it has a little "mouth" in the center of it just like a shroom.

 

looks like a form of sponge. non harmful if it is

 

Do sponges move? I have absolutely not clue how it would have gotten where it is. There is not any coral even semi close to it.

 

They are on most rock live rock we get, I don't think the one you have moves but they do spawn and that is how they show up elsewhere.

 

Not sure if he/she meant moves as in waving or moves as in to a different place. If sponge, as I believe it is, it will not move to a different place. I had about 3 times that amount for a long time and it, shall we say, melted away and have not seen any since.

 

Its a sponge, I have some very similar almost a tint of green. I have em in blue, purple, and even got them growing in low lit parts of the tank such as caves in the live rock, noticed loads popping up in my canister filter, bubble box for the skimmer etc.

 

She meant move as in wander around. Sorry, that wasn't a very specific question. As long as it's not harmful and not going to suddenly try to overtake my tank I guess I'll just let it be. Thanks for the help!

 

it looks like the bottom part of an anemone

 

That was the first thing that I thought. I did have a nem die about 4-5 months back and never found the remains. Is there a part that never decays? Could that be what it is? I've looked at a ton of pics of sponges and it's hard to tell from the picture, but it doesn't look like any that I can find a picture of.