Yellow Belly Zoanthids

Yellow Belly Zoanthids, Zoanthus sp., are colonial zoantharians known for their vivid color contrast and mat-forming growth. This WYSIWYG colony displays bright fluorescent yellow centers surrounded by deep red to burgundy oral discs and skirts, creating the bold high-contrast appearance associated with the Yellow Belly color morph. The individual polyps are tightly packed across the rock, forming a dense colony with strong visual impact under reef aquarium lighting. Zoanthus polyps are connected by living tissue and can gradually spread across adjacent rockwork under favorable conditions. They contain symbiotic photosynthetic dinoflagellates that provide much of their energy, while the polyps may also capture very fine suspended organic material. Because aquarium color morph names do not correspond reliably to a particular species, Zoanthus sp. is the scientifically appropriate identification.

Care Guide: Zoanthus sp. generally performs well under low to moderate lighting, although established colonies can tolerate moderately strong reef lighting when acclimated gradually. Provide low to moderate, variable water flow that keeps debris from settling between the polyps without preventing them from opening fully. Place on stable rockwork with room for the colony to spread. Maintain stable temperature and salinity along with reasonable alkalinity, calcium, magnesium, nitrate, and phosphate levels. Most nutrition is obtained through photosynthesis, though fine suspended foods may provide supplemental nutrition. Zoanthids can contain palytoxin or related compounds, so wear gloves and eye protection when handling or fragging, avoid touching your face during handling, and never boil or expose zoanthid-covered rock to hot water or steam.