Fish diseases: Anchor worm - crustacean from the group of cladocerans

Symptoms: Red and inflamed scales, itchy skin, which causes fish to rub against the walls of the tank.

Short white worms protruding from behind the scales. The end of the white worm may have one or two egg sacs attached. These sacs contain their eggs and will fall into the aquarium, where they will hatch. They can also be found in the fish's mouth.

Spots on the skin and red lesions

Anchor worms that fall off the fish can leave behind bloody spots or fibroses on the skin. Bacteria can infect the site where the anchor worm was attached, causing red lesions on the fish's skin.

Treatment: Visible anchor worms should be carefully removed with tweezers, followed by the application of antibiotic ointment to prevent secondary infections. It is also important to clean the entire tank to remove the eggs and larvae.

Causes and prevention of Lernaea worms in aquarium fish

Lernaea anchor worms are external parasites that can cause serious health problems in aquarium fish. These parasites are particularly dangerous because they can rapidly multiply and spread among the host fish. One female can produce hundreds of larvae every two weeks at 25°C. Parasites appear, for example, when a new fish, already hosting the parasites, is added to the aquarium.

Insufficient quarantine of newly added fish or plants can lead to the rapid spread of these parasites. Anchor worms can also be introduced with live plants, even if they are not directly on the plants themselves. Therefore, it is crucial to thoroughly quarantine both new fish and plants to prevent the introduction of parasites and bacteria into the aquarium.

Diagnosis and treatment of anchor worms

Diagnosis is usually visual, as the anchor worms are visible as threads or strings hanging from the fish's body. Sometimes they are gathered in one spot, forming a small colony, which may also become infected.

If you have a microscope or visit a veterinarian, you can easily confirm the presence of the parasite, but this should not be necessary since they are visible to the naked eye. Once confirmed, it is important to start treatment, as inaction can lead to severe damage to the gills and other organs, making it difficult for the fish to breathe.

1. These anchor worms should ideally be removed under the care of a veterinarian to avoid harming the fish. During treatment, the entire parasite must be removed, for example, using tweezers, including the feeding end.
2. Baths with potassium permanganate (also known as Hypermangan/KMnO4): Treat the affected fish with a bath. Dissolve 1 gram of potassium permanganate in 4 liters of water and leave the fish submerged in the solution for about 5 minutes. Repeat the procedure daily for 3 to 5 days if necessary. The water's GH should not be lower than 6 for this medication to be effective.
3. Use of antiparasitic drugs: Use anti-parasitic drugs specifically designed to treat this type of worm (containing organophosphates or diflubenzuron). Follow the instructions on the drug packaging and administer it at the recommended dosage. Medications must be used cautiously and always under the supervision of a professional.

Prevention

Preventive measures are essential for maintaining a healthy aquarium.

1. Thorough quarantine of all new additions, including fish and plants. Proper quarantine of new fish will prevent the spread of parasites to the main aquarium and protect the health of other fish. Timely intervention and ideally proper quarantine can significantly reduce the risk of spreading these worms and other contagious diseases in the aquarium environment.
2. Maintaining water quality: Regularly clean and monitor the aquarium. Poor water conditions can weaken the fish's immune system and increase their susceptibility to worm infections, which thrive in dirty environments, so maintaining cleanliness is crucial.
3. Avoid overcrowding the tank: Overcrowding can increase stress in fish, making them more susceptible to infections.
4. If you have multiple tanks, avoid sharing nets, equipment, or other items between them without proper disinfection procedures.
5. Maintain a balanced diet: Provide your fish with quality nutrition and avoid overfeeding. Well-nourished fish are less susceptible to parasitic infections.
6. Depending on the situation, consider adding natural predators to your tank's ecosystem. Certain species of small fish or crustaceans feed on crustaceans similar to these anchor worms.