Water from Urban Streams Slows Growth and Speeds Metamorphosis in Fowler's Toad (Bufo fowleri) Larvae

We evaluated the effect of a potentially stressful urban aquatic environment on growth and development of Fowler's Toad (Bufo fowleri) larvae. We reared larvae to metamorphosis in water from urban and forested streams in a laboratory setting. We found no evidence of oral disc anomalies associated with urban environments, but we did find that tadpoles in these environments were smaller at 26 days of age (but not at metamorphosis) and metamorphosed faster than tadpoles reared in water from forested streams. The observed results were partially consistent with the predictions of H. M. Wilbur and J. P. Collins, who suggested in 1973 that stressful aquatic environments should result in an earlier date of metamorphosis for larvae attempting to escape that environment. We suggest further work to pinpoint factor(s) responsible for the results we observed, and we relate our findings to previous findings of declines in amphibian species richness in the study area.