The Effects of Salinity on Canadian Toad (Anaxyrus hemiophrys) Larvae and Post-Metamorphic Juveniles

Abstract

Sodium Chloride (NaCl) production in the United States is at an all-time high. As weather patterns become harsher through climate change and demands on energy and agriculture increase, evidence of long-term NaCl exposure is emerging throughout environments. With a focus on Canadian toads, this research seeks to fill existent gaps of NaCl effects on tadpoles and post-metamorphic juveniles for this species. Chapter 1 of this thesis examined the effects of NaCl on larvae exposed at multiple developmental time periods. Weight, survival, and hatch success were not affected by NaCl, however time taken to complete metamorphosis was extended in tadpoles exposed at an older age. Chapter 2 of this thesis examined the effects of NaCl infused substrates on post-metamorphic juvenile choice, weight, and consumption. Weight gain and decreased consumption rates were observed in high saline treatments, while salinity did not affect the toad’s choice between saline and freshwater substrates.