1. U.S. Fish and Wildlife Service La Crosse Fish Health Center Onalaska Wisconsin54650USA
2. College of Veterinary Medicine Diagnostic Laboratory University of Illinois Urbana Illinois61802USA
3. Iowa Department of Natural Resources Guttenberg Fish Hatchery Guttenberg Iowa52052USA
4. Department of Pathology College of Veterinary Medicine Mansoura University Mansoura35516Egypt
5. Department of Pathobiological Sciences University of Wisconsin–Madison Madison Wisconsin53706USA