Flat Worms
Similar to Bristle Worms Flat Worms come in a variety of sizes and colors, some breathtaking specimens. Some are truly parasite feeding on corals, while others more of less scavenge feeding on detritus, diatoms, and dead organisms. Non-parasitic flatworms are of no danger, and most die off due to lack of food source in the Aquaria.
One of the aspects that makes some of these worms problematic is that they can reproduce both sexually and asexually making to potential for an explosive population in a short time. This page is dedicated to he problems of one particular species Planaria. For reef aquarists this is perhaps the most common flatworm we encounter and certainly one that can cause problems in our system. Red Planaria is a common flatworm that we occasionally experience an outbreak from in our reef tanks, they are believed to ingest photosynthetic zooxanthellae. The population of the Red Planaria can compound quickly in a brightly lit system.
The worms can easily overrun the tank. Documentation is light to support that these worms actually devourer coral, however they must certainly be a nuisance I have had great success in controlling and eliminating the population by adding a predatory fish such as a 6 line wrasse. Red Planaria has never caused my systems any problems other than being aesthetically unappealing. This may be a common scene for those of you whom have experienced flatworms. Planaira like this have reportedly infested soft, and hard corals, as well as Discosoma.If left to their own the worms will certainly multiply. From my observations corals in my system acting as host to the occasional flat worm never seemed to be damaged by the organisms.
Documentations does not seem to correlate coral death with an infestation, or at least directly. In this case they may simply be feeding off the surface of the Removal of these worms if predation has not been successful can be a simple a a quick freshwater bath. Make sure to follow the correct procedure in the make up of the water and matching the temperature. A 10 second dip should free the worm from the surface of the coral, and then you can return it to it’s home in your tank. These worms are so small and many transparent that it would be difficult at best to prevent their introduction to your tank. Your best precaution is staying aware of your animal and your reef system for prevention.