Red Ball Sponges, Pseudoaxinella lunchearta, are a fairly common sponge from Florida and the Caribbean characterized by their bright red color and ball shape.  About 1% or less of these sponges will be encrusted with Parazoanthus swift, which is an encrusting zoanthid that is primarily found in sponges.  When the polyps of the zoanthids are opened up, the sponge almost takes on a fuzzy appearance because of all the polyps.  These encrusted ball sponges tend to be most common in areas where there is a lot of current and a lot of turbidity, so I suspect that they will need frequent, regular feeding to thrive.

 

Sponges are filter feeders, primarily feeding on bacteria and dissolved organics, so they can be a little challenging to keep in some reef tanks.  If not fed regularly with some sort of planktonic food, the will slowly starve to death in most reef tanks, so be prepared to feed them on a regular basis.  Most sponges will have a small amount of substrate attached to their bases which can be superglued or epoxied to a rock so they will stay put in your aquarium.  You can also wedge the sponge into a crack in the rockwork of your tank, but I would not recommend “planting” them in the sand because the base may end up dying.  Contrary to everything you’ll read about sponges, these sponges can be safely removed from the water and exposed to air for brief periods of time without any lasting damages.  We’ve handled thousands of these sponges over the last 30 years and most have been exposed to the air for brief periods of time without any problems, so don’t make a huge deal about not letting the sponge touch the air while you move it from tank to tank or while you mount it on a rock..

 

Our target size for the zoanthid encrusted ball sponges is 3” to 5” in diameter and about that many inches tall.  The zoanthids will usually be yellow, but occasionally we find some that are almost white.   The sponges are wrapped in paper towels and submerged in water for shipping and they generally ship real well and will do well in your tank.