Red Ball Sponge with Encrusting Zoanthid, Pseudoaxinella lunchearta, are very uncommon 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. The zoanthids will usually be yellow, but occasionally we find some that are almost white. 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.
Red Ball Sponge with Encrusting Zoanthid 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.
Medium: 2 to 3 inches
Large: >3 inches