Bothriocephalus acheilognathus

From Fish
Common carp parasitized by Bothriocephalus
The scolex with bothria of B. acheilognathi

The Asian carp tapeworm, Bothriocephalus acheilognathus, is occasionally seen in carp and aquarium fish.

Clinical signs

It is usually found in the anterior intestine and may be associated with enteritis and degeneration of the intestinal wall. Most of the villi intestinales are seriously destroyed. Haemorrhage, haemolysis or vesiculation occurs in the lamina propria mucosae. Affected fish do not die and continue to feed actively, though the histopathological changes are serious. Since this parasite is not infectious to human, it is harmless in food hygiene[1].


The parasite can be visually observed in the gut. Confirm the scolex with bothria by light microscopy.

Recently, Bothriocephalus acheilognathi was introduced to Europe and U.S.A., probably by transportation of the ornamental fish. The parasite is harmful to cyprinids, which are highly susceptible to B. acheilognathi.


Praziquantel is the drug of choice for treatment of cestodes in fish, but it is not approved for any aquatic use. It can be applied as a bath (2 mg/L for prolonged immersion or 10 mg/L for 3 hr) or in a medicated food (50 mg/kg, 1 time)[2].


  1. Merck Veterinary Manual
  2. Nakajima, K. and S. Egusa (1974) Bothriocephalus opsariichthydis YAMAGUTI (Cestoda: Pseudophyllidea) found in the gut of cultured carp, Cyprinus carpio. I. Morphology and taxonomy. Fish Pathol 9:31-39