1. Department of Pathology, New York State College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
2. The Registry of Comparative Pathology, Armed Forces Institute of Pathology, Washington, D.C. 20306, USA
3. Aquatic Pathobiology Center, Department of Pathology, School of Medicine, University of Maryland at Baltimore, 10 South Pine Street, Baltimore, Maryland 21201, USA