Can someone tell me what this is

[jbillens]

I fount this today in my tank while i was cleaning some of that green hair algae off my rocks. It is shadded under a rock and not in the direct light.

 

[fishfreek]

Hmmm...it may be some type of sponge. I have some in my tank that look similar to yours, but are different colors, mine are white, yellow and pink types. :thinking: