The Green star polyp is a hardy colonial invertebrate commonly kept in aquariums. Its characteristic bright green star-shaped polyps seem to glow in the sunlight. These tiny filter feeders can absorb organics from the water column, and like other corals, the polyps of this species also house zooxanthellae, photosynthetic algae cells which provide the coral with nutrients. A purple mat of tissue, known as a stolon, connects the multiple polyps, often covering the rock beneath it.