Knob Coral

About

Knob Coral (Dipsastraea danai) is a benthic, tropical coral documented from the reef systems of Guam in the Western Central Pacific. As a member of the Dipsastraea genus, it shares the characteristically robust, dome-forming or encrusting growth patterns typical of the group, with individual corallites often presenting as raised, rounded knobs across the colony surface. Hence the common name. In the wild it lives on the seafloor of tropical reef environments, where it contributes to the structural complexity that makes coral reefs such productive ecosystems. Guam's reefs have faced considerable pressure from climate-related bleaching events, making species like this one the subject of ongoing resilience research in the region. In a reef aquarium, Knob Coral is considered intermediate in difficulty. It does not demand the intense lighting that some small-polyp stony corals require, being comfortable under moderate output, and appreciates a steady but not overpowering flow to help with feeding and waste removal. It is fully reef safe and poses no threat to neighboring corals through sweeper tentacles or aggressive chemistry, though standard spacing should still be maintained. Reefers with some experience managing calcium, alkalinity, and magnesium levels will find this a manageable and rewarding addition.