1. Aquatic Animal Health Program, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401, USA
2. Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA
3. North Attleboro National Fish Hatchery, U.S. Fish and Wildlife Service, 144 Bungay Road, North Attleboro, Massachusetts 02760, USA
4. Northeast Fishery Center, Fish Health Section, U.S. Fish and Wildlife Service, P.O. Box 155, Lamar, Pennsylvania 16848, USA
5. National Fish Health Research Laboratory, U.S. Geological Survey, Department of the Interior, 1700 Leetown Road, Kearneysville, West Virginia 25430, USA