Sodium arsenite has been reported to affect swimming performance inR. pipiens(Chen et al., 2009), which could increase their
vulnerability to predators. The benefit of an accelerated metamorphosis is obvious as it enables tadpoles to come out of the stressful
environment. However, the developmental deformities in the
metamorphosed individuals presently observed as well as the
smaller size at metamorphosis could be the immediate costs of this
developmental plasticity. Since most of the physiological changes
occurring during pro-metamorphosis involve development rather
than growth, arsenic exposure influenced the rate of differentiation
but not mass at metamorphosis.