Zoanthid and palythoa coral

Zoanthids and Palythoa form colonies of individual polyps that spread across a connected mat. Start with a defined rock area and leave room at the edges, especially beside slower-growing corals that could be covered as the colony expands.

Acclimate new colonies from lower light and provide circulation that keeps waste from settling between polyps. Photosynthesis provides substantial energy; small suspended foods may be captured, with Palythoa often feeding more readily. Persistent closure calls for checking sediment, pests and irritation before repeatedly changing the whole aquarium's conditions.

Treat these corals as potentially containing palytoxin. Use gloves and eye protection when handling them, keep tissue damage and splashing to a minimum, and never boil or heat colonised rock. A familiar trade name or small frag size cannot establish that a colony is toxin-free.