What eats flatworms?

Answer 1

The best way of controlling flatworms is by prevention. Maintaining low nutrient levels in the aquarium with the use of carbon and aggressive protein skimming, along with increased water flow will help to reduce the populations of these pests. Proper quarantine of new specimens, and all aquatic life before they are placed in the display aquarium will keep the initial introduction of flatworms to a minimum.

• Natural means of control include: Wrasse of the genus Pseudocheilinus, such as the Six Line Wrasse (P. hexataenia), Halichoeres Wrasse, such as Yellow Wrasse (H. chrysus), Macropharyngodon Wrasse such as the numerous Leopard Wrasse (Macropharyngodon sp.), and Dragonets such as the Spotted Mandarin (Synchiropus picturatus). The Blue Velvet Nudibranch (Chelidonura varians) is very effective at consuming flatworms in the aquarium, but is very sensitive to changes in water chemistry and has a short life expectancy in the home aquarium.
• Although the species mentioned above will consume flatworms, they may not feed on all of the different species that inhabit the aquarium, nor will they typically rid the aquarium completely. Also be sure that your aquarium is appropriate for the fish, as some of the species do have special requirements and increased care levels in the home aquarium.
• Another method of removing flatworms from an infected colony is by performing a brief freshwater bath or dip. Flatworms are very sensitive to salinity changes; by dipping the colony in dechlorinated freshwater for 5 to 10 seconds and then shaking the colony while submerged in the bath of freshwater, will cause the worms to lose their grip and fall to the bottom of the container. Be sure the freshwater has the same temperature and pH as the aquarium's water in order to reduce the amount of stress on the colony.
• The last method involves manual removal. Siphoning seems to work the best, as the flatworms do not keep a very strong grip on the colony. A small diameter airline tubing works very well for soft leather coral colonies and some species of mushrooms. Be careful not to damage the coral with too strong of a siphon. For the more delicate mushrooms and LPS corals, small syringes work very well. It is possible to get the syringe very close to the flatworm and gently draw the worm into the syringe without harming the coral.

With severe infestations, you may have to employ a combination of all methods mentioned above in order to eliminate or even control the populations of these pests.

Answer 2

Free-living platyhelminths (class Turbellaria), mostly carnivorous, are particularly adapted for the capture of prey. Their encounter with prey appear to be largely fortuitous, except in some species that release ensnaring mucus threads. Because they have developed various complex feeding mechanisms, most turbellarians are able to feed on organisms much larger than themselves, such as annelids, arthropods, mollusks, and tunicates (e.g., sea squirts). In general, the feeding mechanism involves the pharynx which, in the most highly developed forms, is a powerful muscular organ that can be protruded through the mouth. Flatworns with a simple ciliated pharynx are restricted to feeding on small organisms such as protozoans and rotifers, but those with a muscular pharynx can turn it outward, thrust it through the tegument of annelids and crustaceans, and draw out their internal body organs and fluids. Turbellarians with a more advanced type of pharynx can extend it over the captured prey until the animal is completely enveloped.