US Fish & Wildlife Service


Date of this Version



Published in THE JOURNAL OF PROTOZOOLOGY 12:2 (May 1965), pp. 273-275.


In March, 1962 this laboratory received some goldfish for disease diagnosis from Mr. Richard Rice, Mercersburg, Pennsylvania. Seven of 29 fish examined were infected with Eimeria. These fish had long, whitish, opaque fecal casts hanging from the anus. The casts were composed almost entirely of oocysts. When shed, they sank to the bottom and looked somewhat like "spent" tapeworms (Figs. 1, 2). The infected fish were very lethargic and their intestines were swollen with contained fluid. Although I believe that the Eimeria is pathogenic, a heavy infection of other parasites made this difficult to determine. These fish had apparently accumulated a heavy load of parasites during the winter; Gyrodactylus, Trichodina, Chilodonella, Glossatella, Ichthyophthirius and Urophagus were present. Some also had bacterial infections of Aeromonas liquefaciens.