These fish inflict painful bites directly on the fibropapilloma, apparently eating parasites that infest the tumors. Afflicted turtles are often forced to leave a cleaning site prematurely. Over time, their tumors worsen and their time at cleaning stations becomes shorter and shorter. A thick coat of algae develops on their shells, and even on their skin. Tumors increase in number and size, resulting in more drag and making swimming more difficult.
Tumors often grow to cover both eyes.
In 1994, we saw a turtle with an eye tumor so large that it obscured half its left profile. Tumors growing in the corners of the mouth make breathing and eating difficult. One turtle we saw had a tumor growing out of its anus. No soft part of a turtle is spared. There comes a point in the disease when you think the turtle is really just a way for the tumors to get around.