Impact of organochlorine contamination on levels of sex hormones and external morphology of common snapping turtles (Chelydra serpentina serpentina) in Ontario, Canada.

Recent research has suggested that contaminants in the environment may influence sex differentiation and reproductive endocrine function in wildlife. Concentrations of organochlorine contaminants (total polychlorinated biphenyls, pesticides) were higher in the blood plasma of snapping turtles from contaminated sites than in those from reference sites. The ratio of the precloacal length to the posterior lobe of the plastron (PPR) is sexually …