Preventing Anchor Worms on Your Pond Fish

Preventing Anchor Worms on Your Pond Fish

Fish Ticks

Anchor worms to fish are much like ticks to dogs, they embed themselves and feed! despite its name, it is not a worm, but a large, parasitic crustacean of the Lernaea species. Although this parasite can infect any fish, pond fish are most susceptible. Once attached to the fish's skin, it buries its head deep into the muscle tissue.


The anchor worm itself is not easily identified until a larger more developed female anchor worm has fully developed and has begun egg production. Once this occurs, the parasite is fully visible and can reach two or two and a half centimeters long. On the exterior of the fish, there is a noticeable sore where the head of the parasite is embedded and a long thin extension gives it a worm-like appearance.

Most of the time, a pond will begin to contract anchor worm when a new fish has been introduced that harbors the microscopic parasites. The females will eventually release their eggs (potentially 700 can be released in a sitting) into the water, escalating the infestation.

Newborn anchor worms are free-swimming microscopic parasites searching for a new fish to feed on. The parasites will feed on fish mucus which is harmless until the process of mating is complete. At which point the female embed themselves in a nearby fish and restarts the process. It is easy to see this issue in a pond can get out of control, quickly!


Fortunately, there is a simple solution, Dimilin. This particular product is effective in targeting parasite of this type in both ponds and aquaria. Dimilin works by interrupting the mating practices of anchor worms hence breaking their life cycles. The Anchor Worms currently embedded in the fish will remain unscathed, but they will be no longer able to produce offspring.

Once the life cycle is broken, the female anchor worm will eventually die and the fish should recover as it is not wise to attempt to remove the parasite from the fish because this could potentially lead to a secondary infection. There is a way to remove the parasite if you must, but it involves the use of a water type salt called Potassium Permanganate. This product can be purchased in places that sell water purification equipment and supply. When dipped in a solution of water and the PP the anchor worm will release its hold from the side or back of the fish and can be gently swept away.


Anchor worm can spiral out of control in a pond in alarming fashion. If left unchecked the worm itself can cause major damage to the pond fish and potentially spawn major infections. Fortunately, at Zamzows we carry the only simple, one step solution to removing anchor worms from your pond!