Knob Coral

About

Knob Coral (Dipsastraea marshae) is a large-polyp stony coral native to the Indo-West Pacific, found across a broad range stretching from the eastern Indian Ocean through to the western Pacific. In the wild it grows on reef structures from the shallows down to about 30 meters, which tells you something useful about its adaptability to varying light conditions. The characteristic that gives this coral its common name is the raised, knobby surface texture of the colony. Individual corallites sit prominently on the skeleton, giving the whole structure a bumpy, almost cobbled appearance that sets it apart from smoother faviid relatives. Coloration tends toward earthy greens, browns, and occasionally muted golds, depending on the zooxanthellae present and the lighting it receives. In the aquarium this is a solid intermediate-level coral. Not a beginner pick, but not a species that demands the kind of obsessive fine-tuning that pushes newer reefers to their limits. It appreciates moderate flow and moderate lighting, and like other members of its genus it benefits from occasional target feeding to support good growth. Give it adequate space on the rockwork and avoid placing it where aggressive neighbors can reach its extended polyps at night.