Meeting Abstract
44.6 Jan. 6 From chemical confusion to chemical castration: endocrine disruption leads to a range of reproductive abnormalities in Bufo marinus living in agricultural areas of South Florida MCCOY, K. A*; GUILLETTE, L. J; ST MARY, C.; Univ of Florida, Gainesville; Univ of Florida, Gainesville; Univ of Florida, Gainesville kristam@zoo.ufl.edu
Endocrine disrupting chemicals (EDCs) cause reproductive abnormalities in a variety of wildlife species. For example, many studies (laboratory and field-based) have demonstrated that the herbicide atrazine induces ovary development or ovo-testes in male frogs at low ecologically relevant concentrations. Importantly, differential exposure to EDCs likely results in variation in these morphological abnormalities; however, few studies have quantified this variation in amphibians living in agricultural areas. In addition, the influence of these abnormalities on reproductive physiology and function remains unclear. Here, we 1) compare the prevalence and severity of various morphological abnormalities in populations of frogs from agricultural areas (where EDCs are used) and non-agricultural (reference) areas, 2) determine how sex hormone concentrations and spermatogenesis differ between frogs from both populations, and as a function of the severity of abnormality, and 3) determine the relationship between reproductive abnormalities and other traits important for sexual identity such as sexually dimorphic color patterns. This study was performed via field surveys at agricultural and reference sites in South Florida. Initial results show that as many as 60% of male Bufo marinus (giant toads) collected from agricultural sites were feminized (e.g. had female coloration), and up to 40% were also intersexed (i.e. had testes and ovaries). Conversely, 4% (on average) of the individuals collected from three reference sites were feminized. Differences in severity of these abnormalities and their relationship to spermatogenesis, hormone concentrations, and sexually dimorphic coloration will be discussed.
