Dark spots disease is characterized by focal to multifocal lesions located within the colony surface and generally surrounded by normal appearing tissue. These may be distinct brown to purple, round to amorphous to oblong areas of discoloration, with smooth to gently undulating edges. The dark spots consist of live coral tissue.
DSD Lesions range in size from about 1-5 cm but they may coalesce over time forming larger lesions. In some cases, the center of these discolored areas may die, with chronic tissue loss occurring over prolonged periods and older denuded areas being overgrown by turf algae.
In more advanced cases of DSD, there may be some erosion of the skeleton, leaving a central indentation colonized by turf algae and bordered by an irregular distinct band of dark discoloration.