Fungal invasion of massive corals

Abstract

Five species of corals from the Andaman Islands in the Bay of Bengal (Indian Ocean) have been regularly found to have single or multiple necrotic patches. The occurrence of such corals with necrotic patches varied from 10-50% in the field. Sections revealed a septate dark brown mycelial fungus on the surface and subsurface of the dead patches in five coral species. The fungus was isolated in culture and identified as Scolecobasidium sp. The fungus formed a distinct dense brown to black zone of 0.5-1.5 cm width immediately below the surface of the corals. In terms of biomass, the fungus was estimated to contribute 3-5 mg.cm-3 of coral skeleton.