A reader recently wrote to us about a worm she found in her aquarium. She wrote that the aquarium is a new project, and only has three fish in it so far. Her husband did bring in some plants from a canal near their home in Lehigh Acres, Florida. She said that the plants have been in the aquarium for a week, but that they have just now noticed the worm and it is quite long. The worm is about 5 inches in length, and it doesn’t appear to want to be submerged. She removed the worm from the aquarium and placed it in a jar filled with tank water. She said that the worm tends to stick to the dry part underneath the lid. She describes the worm as being striped brown. Our reader also provided several photos of the worm. After doing some research, our reader thought this might be a hammerhead, but due to the pointy-head she doesn’t think this is accurate. She hopes we can help her determine what type of worm this is; especially because her and her husband are worried it might be breeding.

We believe that our reader is dealing with a flatworm. These are fairly common in aquariums, and often hide so it makes sense our reader didn’t notice it at first. They also grow at a very fast rate, so it suddenly appears to be very large, but it could still be quite young. The flatworm might have been introduced with the plants, but could have also come through new fish food or another source. Flatworms are not parasitic, but they can grow quite large if not removed from the tank. Since our reader has already removed this worm from the tank, she doesn’t need to know how to get rid of it. However, if more worms arise, there are solutions to getting rid of them. She can relocate her fish to a temporary tank, and increase the aquarium temperature to 95°F. The flatworms should be dead within a couple hours.

In conclusion, our reader was concerned with a worm that appeared in her aquarium. We believe this worm is a flatworm, and provided some easy ways to get rid of the pest!