Orange Dot Zoanthids

Orange Dot Zoanthids, Zoanthus sp., are colonial zoantharians valued for their vivid concentric coloration and dense mat-forming growth. This WYSIWYG colony displays bright orange to coral-red centers surrounded by olive-green to yellow-green oral discs with fine radial striping, finished with contrasting golden-orange skirts. The repeating orange centers create the distinctive “Orange Dot” appearance across the colony. Zoanthus polyps are connected by living tissue and can gradually spread across adjacent rockwork under favorable reef aquarium conditions. They contain symbiotic photosynthetic dinoflagellates that provide much of their nutritional energy, while the polyps may also capture very fine suspended organic material. Because aquarium color morph names do not reliably correspond to a particular species, Zoanthus sp. is the scientifically appropriate identification rather than assigning an unsupported species name.

Care Guide: Zoanthus sp. generally performs well under low to moderate reef lighting, although established colonies can tolerate moderately strong lighting when acclimated gradually. Provide low to moderate, variable water movement that helps keep debris from settling between the polyps without preventing full extension. Place on stable rockwork with enough room for the colony to spread. Maintain stable temperature and salinity along with consistent alkalinity, calcium, magnesium, nitrate, and phosphate. Most nutrition is supplied through photosynthesis, although very fine suspended foods may provide supplemental nutrition. Zoanthids can contain palytoxin or related compounds, so gloves and eye protection are recommended when handling or fragging, and zoanthid-covered rock should never be boiled or exposed to hot water or steam.