Effects of mosquitofish and ammonium nitrate on activity of green frog (Lithobates clamitans) tadpoles: A mesocosm experiment

Abstract

We conducted a mesocosm experiment that allowed us to examine the effects of mosquitofish (Gambusia affinis) and ammonium nitrate on the activity of green frog (Lithobates clamitans) tadpoles under the more natural conditions of a mesocosm as opposed to a laboratory experiment. The proportion of active tadpoles was lower in the presence of mosquitofish than when mosquitofish were not present. There was no effect of ammonium nitrate or interaction between mosquitofish and ammonium nitrate on tadpole activity. These results suggest that green frog tadpoles reduce their activity levels in the presence of mosquitofish, but the ability of ammonium nitrate to mediate the outcome of potential predator-prey interactions between green frog tadpoles and mosquitofish appears to be limited, at least at the ecologically relevant concentration we studied. © 2011 Taylor & Francis.