DAO 41:211-217 (2000)  -  doi:10.3354/dao041211

ABSTRACT: A high incidence of tumors (i.e., abnormal skeletal growth) was observed on Montipora informis Bernard, 1897 (Acroporidae) coral colonies on the shallow reef flat of Sesoko Island, Okinawa, Japan. Tumors were recognized as slightly hemispherical protuberances and were characterized by fewer numbers of polyps per surface area, fewer zooxanthellae per polyp, and finer skeletal structures than normal. In addition, fecundity was significantly reduced in tumored areas. Tumor formation appeared localized, stable and non-epidemic. During the summer of 1998, coincident with the global coral bleaching event, tumored tissue suffered higher mortality than normal tissue. The mechanism triggering tumor formation remains unknown.

KEY WORDS: Coral · Tumors · Abnormal growth · Bleaching · Montipora informis · Reproduction