gelatinous substance on/in the rocks

[B Lo]

Have you ever seen any opaque gelatinous substance on/in the rocks? I noticed a few rocks that had this in crevices - some much more than others. I just chiselled those parts off. My wife asked me what it was and I shrugged and told her it might be an alien sea creature.

The seller replied it could be "a lot of things, from sponges to tunicates to certain types of algae."



I tried to remove as much of the rock that had this crap on it as possible. But it looks like I missed at least one piece and it ended up in my tank. Should I remove this rock (below) and try to chisel off the affected piece? Any real ideas what it might be?



Thanks in advance for any suggestions.