1. Department of Biology; University of Waterloo; Waterloo Ontario Canada
2. Center for Environmental and Human Toxicology and Department of Physiological Science, Genetics Institute; College of Medicine, University of Florida; Gainesville Florida
3. Department of Biology; Wilfrid Laurier University; Waterloo Ontario Canada
4. Canada Center Inland Waters, National Water Research Institute; Aquatic Contaminant Research Division, Environment Canada; Burlington Ontario Canada