An Epizootic of Anguillicolosis in Cultured American Eels in Taiwan

An epizootic of anguillicolosis caused by the swim bladder nematode Anguillicola crassuswas recently observed in cultured American eels Anguilla rostratain Taiwan. Eels were imported as elvers from the United States and raised at a Taiwanese farm. Necropsy of dead eels revealed A. crassusin the swim bladder and peritoneal cavity. In some eels, hemorrhage and rupture of the swim bladder were also observed. Anemia as well as peritonitis resulting from aberrant migration of A. crassuslarvae may have contributed to the death of these eels. Treatment with the anthelmintic Hodrin® reduced mortality. This is the first report of an anguillicolosis epizootic in American eels in Taiwan.