1. Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, 240 Wise Center Drive, Mississippi State, Mississippi 39762, U.S.A. (e-mail: )
2. Department of Biology, University of New Mexico, 1 University of New Mexico, Albuquerque, New Mexico 81731, U.S.A. ()
3. Thad Cochran National Warmwater Aquaculture Center, Mississippi State University, 127 Experiment Station Road, Stoneville, Mississippi 38776, U.S.A. ()
4. Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, 240 Wise Center Drive, Mississippi State, Mississippi 39762, U.S.A.
5. Department of Biology, University of North Alabama, 459 North Court Street, Florence, Alabama 35632, U.S.A. ()