title: Toxic response of endosulfan to breeding and non-breeding female mosquitofish.
abstract: To investigate if toxic effects by endosulfan, a commonly used insecticide, are dependent on the breeding condition of an organism, both breeding and non-breeding female western mosquitofish, Gambusia affinis, were exposed to 0.1, 0.5, 1 ppb of endosulfan. After a 5-week exposure period, we examined physical factors such as ovary weight and anal fin length in fish of both reproductive conditions and the size of thyroid follicles in non-breeders. Breeding female fish exposed to endosulfan did not show any significant changes in physical factors, but non-breeding females exposed to endosulfan had a significantly greater ratio of anal fin/ body length and larger thyroid follicles than did control females. These results demonstrate that the response to exposure to environmental contaminants may be dependent upon seasonal reproductive condition.
authors.affiliation: Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011-5640, USA. parkda@msu.edu
authors.forename: Daesik
authors.initials: D
authors.lastname: Park
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Minor
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Propper
mesh_terms: D000818:Animals; D049628:Body Size; D003532:Cyprinodontiformes; D004726:Endosulfan / Q000633:toxicity*; D005260:Female; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D010053:Ovary / Q000254:growth & development / Q000473:pathology; D012098:Reproduction / Q000187:drug effects; D012737:Sex Factors; D013961:Thyroid Gland / Q000254:growth & development / Q000473:pathology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D004726:Endosulfan