I have a very special animal in my aquarium and I am afraid I have subjected it to flatworms. How do I get rid of the flatworm without harming my pet? I have a 55 gal aquarium that is home to a lesser siren. It is 18 inches long. I am afraid I have unknowingly put flatworms into the tank when I placed some live plant bulbs or sand into the tank. Now I dont know what to do. I am afraid I have put her in harms way. What should I do? Will flatworms harm my siren? How can I tell if they have? The only other things I have in the aquarium are snails and one very small crawfish. I do have fake plants, shells, and stumps for my siren to hide and play in but no other fish.

Most flatworms like planaria live on debris, leftover fish food and such. They shouldn't harm your siren. Are they crawling on her? Keep an eye on her for signs of skin damage but I really doubt the flatworms will hurt her. What do the worms look like? If they're small and white, they're probably planaria. I've had them before but not now. My tanks have a few individual larger brown planaria that I find in the waste after gravel vacuuming.

To control them, feed less, clean more, and that may be enough. You can also try baiting them.

From my web site:

"Flatworms
Flatworms or Platyhelminthes include flukes, tapeworms, and turbellarians. The first two are familiar parasites. The latter move around on surfaces using cilia and eat small living or dead animals. Planaria, a common turbellarian, often over-reproduce in aquaria but I do not think they are a problem in ponds. Other turbellarians are also rather harmless. Dugesias tigrina is the largest free-living flatworm, growing to an inch long.

Planaria:

If small white creatures are seen crawling all over the glass and ornaments, especially at night, they may be planaria. Planaria commonly show up in tanks with an excess of food. Most are introduced to an aquarium from other aquaria with live foods like black worms, live plants, or anything else moved from an active aquarium that has them. There is some belief that they can survive in freeze-dried or frozen foods. If a lot of food is left in a tank; including dead and dying fish, snails, other animals, and plants; then a few planaria may divide into hundreds very quickly. They usually reproduce by asexual fission. Their heads are shaped like arrow heads. If a tank is found to be infested, planaria can be controlled by a good vacuuming of the gravel and better tank maintenance. To remove more planaria, see the next section on controlling planaria. Planaria will eat dead fish, fish eggs, and immobile fish larvae (fry newly hatched). They do not pose any risk to mobile fry or adult fish.

Controlling planaria in aquaria:

1. Set out bait like meat in a mesh bag. Remove the bait a few hours after the lights go out on the tank. It should be covered with planaria. Throw away and repeat until the population goes down.
2. Add planaria eating fish to the tank. One species is the paradise fish.
3. Vacuum the gravel very well and do a 50% water change. Often, planaria proliferate when the tank is too dirty. This will remove not only some planaria but their food source as well.
4. Reduce the foods added to the tank. Planaria often proliferate if too much excess food is provided.
5. As a last resource, tear down the tank. See here for information on tearing down tanks."


I hope that helps!

First of all, I think your website is absolutly wonderful and I am so glad that I have found it. It is so full of helpful information! You have giving me some some great info that I am going to try starting today and I will let you know how it goes. The worms are flat clear whitish looking. They stick to the sides of the glass mostly but do go from plant to plant during the day by stretching head to tail. At night they seem to gather at the top edge of the water. Also if you pick one out of the bigger ones out of the water it has lots of little ones hanging on it.
Will these worms eat siren eggs? I noticed it said that they eat fish eggs.

Thank you
Lanie

It sounds like you have planaria.

Do your sirens lay eggs? If you had a ton of hungry planaria, they might be able to overcome siren eggs. If there's not that many planaria, it's probably not a problem.