Q: My fish has something red on its side. What could it be?
Ted – White Marsh, MD
A: It sounds like your finned pal has a parasite called anchor worm. And they’re no fun.
These copepod crustaceans from the genus Lernaea bury themselves into the muscles of fish where they live and grow for several months, transforming into an unsegmented worm-like protrusion. Once developed, they make their way out of the fish, leaving behind bad wounds – which is the red area you’re seeing on your fish. Right before anchor worms die, they release their eggs and the cycle repeats over and over again.
A fish suffering from an anchor worm infestation will show the following signs:
- Frequent rubbing or ‘flashing,’ which is when it rubs its body up against objects attempting to dislodge the parasite
- Localized redness
- Inflammation on its body
- Tiny white-green or red worms in wounds
- Breathing difficulties
- General lethargy
Parasites like anchor worms can be introduced into the pond when new aquatic critters or plants are added to the existing mix. Unbeknownst to water garden hobbyists, the anchor worms hitch rides on the other fish or in the soil and roots of plants and establish themselves in their new home.
The cure for anchor worms is a pond-wide treatment with an anti-parasitic medication like KnockOut™ PLUS. As soon as you see signs of anchor worm, pour the recommended amount in your pond daily for seven consecutive days. When the infection clears up, continue treatment for an additional three days to ensure the parasites are gone for good.
If you plan to add fish or plants to your pond this summer, you can also use KnockOut™ PLUS as a preventive. It treats a variety of other fish ailments, including ich, fungus and flukes. Simply add it to the water when you introduce the new pond inhabitants.
Good luck getting those anchor worms under control. We hope your fish feels better soon!
Pond Talk: Have your fish suffered from some sort of parasite? How did you get rid of it?
Filed under: Fish Diseases, Fish Population, Koi & Goldfish, Water Gardens & Features Tagged: | anchor worm, fungus, how to treat anchor worm, how to treat fungus, ich, ick, knockout plus, sick fish, treating anchor worm