Detection of myxozoan parasites in oligochaetes imported as food for ornamental fish

To determine the potential for dissemination of myxozoan parasites by transfer of their alternate oligochaete hosts, shipments of tubificid worms obtained from an overseas commercial aquarium supplier were screened for actinospore stages of myxozoan parasites. At least 7 different triactinomyxon types were identified. The morphological characteristics of the actinospores recovered front these tubificids shared characteristics with triactinomyxons characterized in other surveys, particularly from eastern Europe. Analysis of the screened samples by polymerase chain reaction and comparison of morphological data indicated that these actinospores did not correspond to the triactinospore of Myxobolus cerebralis. Although identification of these triactinomyxon types was beyond the scope of this study, these data suggest that the unregulated import-export and exchange of live organisms for ornamental fish food may result in accidental introduction or dissemination of myxozoan parasites.