When the Blue Photo Sponge, Collospongia auris, first started to become available in the marine ornamental trade, we were apprehensive that this reef organism wouldn’t take over and smother corals like the chicken liver sponge often does. We’ve now seen the Blue Photo sponge growing in a few reef tanks and it so far it hasn’t displayed the kind of invasive growing habit that makes the chicken liver sponge so deadly.
What makes Collospongia unique is that not only is it photosynthetic, but it’s also very beautiful; under dim light it’s at least purple and in strong light the Blue Photo sponge gets iridescent blue as in these wonderful images from Morgan Mok of Reef Gardener. We’ve recently acquired a piece of the Blue Photo sponge but we still don’t quite know very much about it. If you’ve grown or are growing Collospongia in your reef please do share your experiences about this fascinating creature in the comments.
I have pretty extensive experience of collospongia, An interesting observation I have made is that Cyanobacteria tends to disappear when collospongia is added to the tank. I don’t know if it has been a coincidence or if collospongia actually fights Cyanobacteria. I have made som research and apparently collospongia has Cyanobacteria in its tissue. Perhaps it is some sort of competition?
Anyway, I have never had any problems with overgrowth but it seems to prefer strong light.
This can be VERY invasive if left unchecked.
Myself & another reefer have it growing everywhere.
I have resorted to removing rocks & picking it off with either pliers or a hemostat, which works better.