The Black Band Disease of Atlantic Reef Corals.

Tissue necrosis in reef corals is associated with the appearance of the cyanobacterium, Phormidium corallyticum Rützler & Santavy, occurring in dense growths at the boundary between living and dead polyps. Studies at several sites in Florida, the Bahamas and Jamaica confirm the correlation between diseased tissues and the growth of this cyanobacterium. As a prerequisite to further investigations of the disease, its causes and control, Phormidium corallyticum was isolated from necrotic areas on four separate species of reef corals, and grown in axenic culture using liquid and semisolid media. Data on its growth and nutrition in culture are presented. Growth rates appear to be sub‐optimal under the conditions used, suggesting possible nutrient deficiencies that could not be identified in this study. Phormidium corallyticum will grow in the dark or with low light (20μEin m‐1 s‐1) when the medium is supplemented with a range of organic compounds.