Transmission of growth anomalies between Indo-Pacific Porites corals

In this study we provide experimental evidence of transmission of growth anomalies (GAs) between corals. Twenty-four aquaria (16 experimental, 8 containing only apparently healthy corals) were set-up on Negros Island, Philippines, to test for direct-contact and waterborne transmission of GAs. Within seven weeks, two of 16 apparently healthy colonies placed in direct contact with colonies having GAs developed multiple GA lesions whose size and number increased over time. One of 16 apparently healthy colonies in experimental aquaria not touching any diseased colony also developed a GA, exhibiting a single lesion that did not increase in size. Apparently healthy colonies (n = 24) in aquaria without a diseased colony remained unchanged.