Department of Biology, Canadian Rivers Institute, University of New Brunswick, Saint John, NB, E2L 4L5, Canada.|Center for Environmental and Human Toxicology & Department of Physiological Sciences, UF Genetics Institute, University of Florida, Gainesville, Florida, 32611, USA.|Department of Biology, Canadian Rivers Institute, University of New Brunswick, Saint John, NB, E2L 4L5, Canada. jeffhoul@unb.ca.