Meeting Abstract
P3.51 Monday, Jan. 6 15:30 Changes in endocrine status and gonadal morphology in mangrove rivulus exposed to ethinyl estradiol LEE, E.A.*; SCHMITT, A.; EARLEY, R.L.; The University of Alabama; The University of Alabama; The University of Alabama lizlee423@gmail.com
A diversity of aquatic organisms inhabit mangrove ecosystems, which are rapidly becoming imperiled due to anthropogenic influences. Many mangroves are exposed to wastewater treatment plant effluents, potentially subjecting organisms to endocrine disrupting compounds (EDCs) such as ethinyl estradiol (EE2). The mangrove rivulus (Kryptolebias marmoratus) thrives in mangroves and is an excellent model organism in which to assess anthropogenic effects at the organismal level. Populations consist of self-fertilizing hermaphrodites with males being quite rare. Studies have shown that male fish exposed to EDCs in freshwater habitats show a dramatic reduction in androgens. We hypothesized that individuals exposed to EE2 would exhibit changes in estradiol (E2) and 11-ketotestosterone (KT; a fish androgen) as well as changes in gonad morphology. We used 116 individuals (58 hermaphrodite, 58 male) from four isogenic lineages. They were kept in 500 ml glass jars with 25 ppt salt water for 30 d. Each day the water was changed and half of the animals received a dose of 4 ng/L EE2 while the other half received vehicle. At 30 d we collected waterborne hormone samples from a subset of individuals and excised gonads for histological analyses from the remaining. Exposed males showed a decrease in KT while exposed hermaphrodites exhibited no change. Both sexes showed a decrease in E2 when exposed. Males also showed a significant decrease in sperm density as a result of EE2 exposure, but no significant changes occurred in the gonads of exposed hermaphrodites. Our findings provide insights into how EDCs might disrupt reproduction in fishes and raise questions concerning the extent of exposure and the mechanisms driving EDC accumulation in mangrove ecosystems.
