Ornamental fish are often attacked by tapeworms. The parasitosis, which must be treated, occurs mainly when feeding on live food. Fish can be both end hosts and intermediate hosts for tapeworms.

Definition of the disease/disease including symptoms

Tapeworms are not only found in the fish, but also in other aquarium animals in case of heavy infestation. Developmental stages of the parasites are ingested with the live food and develop into sexually mature tapeworms in the fish’s intestines. The worms attach themselves to the intestinal mucosa and cause inflammation. In the case of severe infestation, the intestine can break through.

White parts of the tapeworm are visible in the slimy faeces of the fish. Often worms are also visible, which hang directly from the anus of the fish. The tapeworms remove nutrients from the food mash, the fish are no longer sufficiently supplied. They lose weight. The eyes appear cloudy, the gills lose colour. The fish feel sick, they take up less food. The stomach is distended, the back is pointed. The fish withdraw and look weak. The swimming behaviour is changed.

If the fish serve tapeworms as intermediate hosts, the muscles are attacked by larval stages. Painful inflammations and punctiform bleedings develop.

Summary of symptoms

  • Emaciation
  • mucous feces
  • visible parasite parts
  • delayed growth
  • altered swimming behaviour


Various tapeworms parasitize in the intestines and muscles of fish. The tapeworm eggs enter the water via food or infected pets.

The fish as final host

Clove tapeworm – Caryophylleaus

The tapeworm, which can be up to 100 mm long, has a head with a sucking hole and two lips that resemble the appearance of a clove. Clove tapeworms do not form limbs with egg sacs, they are unisexual. The flat body is wider in the front part than in the rear part. If there are more than ten worms in the intestine of the ornamental fish, clinical symptoms occur. Ten different species are known in Europe so far. Aquarium fish are mainly infested by Khawia sinensis and Atractolytocestus huronensis.

The fish as intermediate host

The larval stages of lugworms, carp tapeworms and fish tapeworms parasitize in the muscles of the fish. These tapeworm species are especially important in pond keeping.

Tapeworms in fish

  • Clove tapeworm
  • Fish tapeworm
  • Tapeworm
  • Carp tapeworm


The first symptoms appear only a few hours after the infestation. Treatment with medication can prevent severe intestinal damage and intestinal rupture. If no treatment is given, the parasitosis is fatal within a few weeks. In small ornamental fish, death occurs more quickly than in large fish.


Infected fish must be isolated in a quarantine aquarium. Treatment is by administration of praziquantel or fenbendazole (Panacur) with the food. The water must be partially or completely replaced during and after treatment, depending on the level of infestation.

As a preventive measure, new stock should always be kept for a few days in a separate aquarium. The risk of infection is reduced by avoiding fresh food such as tubeworms or copepods. Optimizing water temperature, water hygiene and aquarium design reduces the risk of parasite infestation.

Be the first to comment

Leave a Reply

Your email address will not be published.