ABSTRACT
INTRODUCTION The possible effects of endocrine disrupting chemicals (EDCs) on invertebrates, fish, and wildlife populations have been described elsewhere (for reviews, see Ankley and Giesy, 1998; Tyler et al., 1998; WHO, 2002). Although purported effects are in some instances relatively speculative, there have been several cases in which EDCs clearly affected animals in the field. For example, there is little doubt that chemicals associated with certain industrial and municipal discharges have affected endocrine function in fish worldwide (WHO, 2002). Partially in response to these observations of endocrine-mediated effects, most EDC screening and testing programs around the world include fish assays (Ankley and Johnson, 2004). In addition to representing a potentially sensitive taxa, fish assays provide broader taxanomic and physiological representation and provide another exposure route to EDC test suites that otherwise would rely solely on rodent assays to identify chemicals that affect the hypothalamic-pituitary-gonadal (HPG) axis (USEPA, 1998). In vivo fish assays developed for EDCs range from relatively short-term (e.g., 21 days) reproductive tests to multigenerational assays (Ankley and Johnson, 2004).
