unknown white algae

[cdgras]

For the past couple days i've notice a new white substance growing on one of my rocks in my saltwater reef aquarium. It has a fuzzy mold look but its beginning to branch out and I've notice a few more smaller ones around on the same rock. I haven't been able to determine what it is any ideas? Here is a picture with it in the tank and of one plucked out.

 

[Fuzz16]

Pica are hard to tell, but are they sponges? Ive never seen mold in sw tanks. Were the rocks established or dry when you got them?

 

[cdgras]

Sorry about pics, in a hard to see spot. I'm not sure if they could be sponges or not, there is a red tree sponge sitting on that rock as well. but i'm not sure if there is a connection between the occurances? The rock was dry but its been established for many months now without any problems. There is also a Kenya Tree on the rock.

 

[cdgras]

Maybe this picture is a bit better? Its hanging beneath the the edge of the rock.

 

[KcMopar]

Looks like a sponge of some kind. These will grow in areas where there is low to little light. I have some that are yellow and are branching out a bit to. Algae will not normally start growing in the shaded areas first.
Thats a real nice looking Salarias fasciatus you got to!!