Is this growth ok in my reef tank?

[Zoaelite]

Looks like its exhibiting some sort of photo tropism so I would lean away from it being a sponge. What ever it is it looks pretty cool, my guess is some sort of calcareous algae. Anything in your tank go after it as a meal?
Levi

(Only thing is its black, and you don't see to many things that use photosynthesis that exhibit an overall black pigment.)