This soft coral is covered with brown rust flatworms on its main trunk, but does not appear to be harmed.
However, if the flatworms’ numbers build up further, they could prevent the coral from catching plankton, and feeding normally.
The brown color is due to symbiotic algae called zooxanthellae that nourish the worms through photosynthesis.
These worms probably benefit from the protection of the soft coral’s spines.
Matthew Oldfield is a freelance photographer based in Bali, Indonesia, specializing in editorial and documentary images from both above and below the waves. He works primarily with charities, NGO’s, and other organizations working to conserve the environment, endangered species, and disappearing cultures.
