BEHAVIORAL-RESPONSE OF AMPHIBIAN LARVAE TO ACIDIC WATER

Five species of amphibian tadpoles (Rana clamitans, Rana sylvatica, Rana pipiens, Pseudacris crucifer, Bufo americanus) which varied in their sensitivity to low pH were exposed to a range of water pH and observed for avoidance behavior and changes in activity levels. All species tested avoided lethally acidic water and all species except Rana sylvatica avoided sublethal levels of acidity. However, the highest pH at which tadpoles avoided acidic water varied with species and appeared to be related to the acid sensitivity of the test species. Pseudacris crucifer displayed a slight but statistically significant decline in activity level, whereas B. americanus greatly increased its activity level during exposure to acidic water.