Porites trematodiasis is characterized by conspicuous, discrete swollen nodules (~3mm) on colonies of Porites, which range in color from bright pink to white. Small abnormal skeletal protrusions (~2.0mm) develop under each nodule.
Infections may affect a few scattered polyps, or they may exhibit a clustered distribution affecting tens to hundreds of polyps.
Infected polyps are usually pale pink in color and gradually turn medium or bright pink. Over time, the color of infected polyps fade back to white and then to the normal tan coloration of the coral. Paralleling the color change is the development and then subsequent regression of the swelling of the infected polyps.
Porites trematodiasis does not usually kill its coral host