Corals command so much of the spotlight when it comes to aquariums, it’s easy for us reefers to forget that there’s an incredible diversity of other creatures that populate the reef environment. One such critter that caught our attention on the Fluval Sea Flores Expedition is this fascinating blue sponge we found living mere feet from that colony of Acropora abrolhosensis that we already reported on.
The thin branching blue sponge we observed is a gorgeous shade of blue that was incredibly bright in the full sunlight to which this sponge was exposed. We presume this sponge to be photosynthetic since we didn’t see it growing anywhere that was shaded and the color was dulled in places where debris had settled onto the sponge colonies.
Thanks to Julian Sprung’s zoological prowess, we were able to give the Flores branching blue sponge a tentative identification of Callyspongia samarensis although identifying sponge to the species level can be really difficult. There is actually a very similar looking sponge that is commonly found in aquariums already which appears all but identical save for usually being green or sometimes red.
The red or green ‘presumed’ Callyspongia that lives and thrives in aquariums is a really cool animal in that it grows into attractive colonies in well lit aquariums yet it doesn’t grow out of control like some other aquarium-suitable photosynthetic sponges. We also know that the thin branching sponge found in aquariums is symbiotic with a species of cyanobacteria because when the tank water is treated with a red slime remover, often an antibiotic, the sponge will become pale, bleach out and die.
While we haven’t yet seen the blue Callyspongia in aquariums, all it would take is a single piece to settle into aquarium life and grow and propagating it would be as simple as fragging stony corals. At this point it’s probably a matter of it and now when this sponge will make it into the aquarium hobby and when it does, we have no doubt that it will be a very popular aquarium animal.