Anyone Know What This Is

[Skim]

Just wondering if anyone know what this white stringy thing is. It appeared over night.

 

[Shooter000]

Does it appear to be on the rock or from within the rock?

 

[Skim]

I do not think they are from the rock and those are 4 star legs stick out from the mass. I don't know where it can from. The only thing I can think of is it looks similar to what a Cucumber expels and I do have one not that I see it often as it tends to stay buried.

 

[Kman]

Bacterial blooms can do that
. Hard to tell from the pic though.

 

[Kman]

Does it crumble when touched? Or is it spongy?

 

[Skim]

I have not touched it but it does blow in the current at first I thought it was a sponge.