Please identify this strange growth...

[TanksNStuff]

Not sure if this is an actual "Emergency" because I have no idea what this thing is. But didn't really know where else to ask for an ID for this...

It looks like a bunch of gray arms growing out of my rock, and the "hands" appear to be latching onto the rock. One arm is sort of floating, but appears to be reaching for the rock above it. I touched it with my hand and it feels like rubber. It didn't try to retract or hide when I grabbed at it and showed no signs of being alive. I know it's growing though because it has gotten bigger over the past week or so.

I was thinking of just ripping it out, but figured I would ask around first. Any idea what this thing is and is it safe to keep in the tank?

 

[magic]

Tanks

Can't really tell from the picture but your description sounds like a sponge. That's not a bad thing!

Bob

 

[TanksNStuff]

Yea, sorry my camera sucks. :'(

Glad it doesn't sound threatening. I'll do some research on sponges and see if I can find more info.

Thanks for the reply magic.

 

[GregW]

I vote sponge, also

 

[tbone212371]

I 3rd The sponge!
Nice Looking one at that!
Good Filter Feeder! Its a Plus One on the tank inhabitants!

 

[rodclement]

I have it my tank in a zoa colony, sponge it is and the apendages will grow and then from time to time fall off...the grow again...never bothered anything in my tank, looks weird and interesting...

rod

 

[TanksNStuff]

Awesome! Glad to hear it's a good thing and not a bad thing.

After some research, I think it might be a Syconoid sponge, although I haven't seen many pics that look like mine.

 

[JerseyWendy]

Sponge. I'm pretty certain, especially since I have TONS of that stuff growing in/around one rock. Mine gets so bad that I suck some of it out periodically. Never had any ill effects on anything whatsoever, however. I suck some of it out simply because I don't necessarily "enjoy" so much of it.