Yellow band disease, YBD (A-I)

Begins as a pale yellow, circular blotch of tissue surrounded by normal tissue (A), or as a narrow band at the edge of a colony (F). These focal (E), multifocal (I) or annular to linear lesions expand in size a few mm to cm per month, coalesce (H) and slowly migrate across the colony (B-C). The leading edge of the band becomes a light pale yellow or lemon color, while tissue first affected gradually darkens prior to dying (A). Small patches (< 1cm) of recent tissue loss may be observed, but skeletal areas are usually colonized by epibionts (G). May be confused with bleaching. Most common in Montastraea annularis (E) and M. faveolata (A,B,C, H, I) also in Diploria strigosa (D), M. cavernosa (F) and other faviids.