Not sure what this is, sponge maybe?

[WrasseMan89]

I'm acclimating a octospawn that I just got, he has not been dipped yet but I notice an orangish redish thing on the base. Any idea what it might be?

 

[ISpeakForTheSeas]

Most likely a benthic foraminiferan - harmless filter feeder. You can look up pics of Miniacina miniacea and Homotrema rubrum (this one has some pretty intense variation in appearance, you'd want to look for branching varieties to compare with; they'll pull up with a Google images search of the name, but they probably won't be at the top of the results) for comparison.

 

[MAH]

Did it come off when you dipped it? Is it hard, or soft?