Acropora Eating Flatworms
The first symptoms that will be visible is poor polyp extensions and filaments. In the more advanced stages, the coral will be loosing tissue in the manner shown in the below two images.
These flatworms are very hard to observe on the colonies, blending in very well with the coral tissue.
- Iodine: treatment involves removal of all of the flatworms from the system, with requires dipping of the corals. Dipping is done within an iodine rinse solution, made using 500 ml of tank water with 1 ml of Provodine Iodine. Blasting of the corals with water with a syringe gets the flatworms off the corals. Scraping may also be required to remove the eggs.
- Flatworm Exit: (the commercially available produce for treating acoel flatworms), even at highly elevated levels, has been found to have no effect on these types of flatworms.
- Tropic Marin Pro-Coral Cure
- Melafix 10ml per 1liter Saltwater 5 to 10 minute dip dislodge AEFW with turkey baster while in solution.
- Biological Controls - Sixline Wrasse
Note: Please be VERY confident that you have AEFW BEFORE treating with iodine, its very hard on the coral. There is a Reefcentral thread where people have had success with some fluke tablets, again its an out of tank treatement.
Other Genera Effected
Also see Coral Eating Flatworms, which have been observed on a much wider variety of coral species.
-  Three party symbiosis: acoelomorph worms, corals
and unicellular algal symbionts in Eilat (Red Sea) - Journal Marine Biology