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EFFECTS OF EXPOSURE TO THREE STEROID ESTROGENS ON REPRODUCTIVE PARAMETERS IN A FISH TAUTOGOLABRUS ADSPERSUS
Citation:
Mills, L J., R GutjahrGobell, D B. Horowitz, AND G Zaroogian. EFFECTS OF EXPOSURE TO THREE STEROID ESTROGENS ON REPRODUCTIVE PARAMETERS IN A FISH TAUTOGOLABRUS ADSPERSUS. Presented at 41st Annual Meeting of the Society of Toxicology, Nashville, TN, March 17-21, 2002.
Description:
Estradiol (E2), ethynylestradiol (EE2) and estrone (E4) are steroidal estrogens that are released into the aquatic environment in sewage treatment effluent. To determine whether these estrogens impact reproductive parameters in a model fish species, actively-reproducing cunner (Tautogolabrus adspersus) were exposed in the laboratory by implanting a test estrogen subcutaneously in a slow-release matrix. Four tanks with 3 females and 2 males were used per treatment. Treatments were control (matrix only) and 0.05, 0.5 or 2.5 mg/kg of each estrogen. Egg production (per gram female), viability and fertility were determined daily. Pre-exposure, egg production was not significantly different among experiments, averaging 283 eggs/day. Pre-exposure egg viability over the three experiments ranged from 17-20%, while mean egg fertility ranged from 25-52%. In fish exposed to E2, egg production in the high treatment was 108 (?22) compared with 174 (?46) in control, but this difference was not significant. In fish exposed to EE2, egg production in the high treatment (28 ?22) was significantly lower than in control (107 ?28). E4 treatment gave no significant difference in egg production, although egg production in the high (99 ?82) and medium (104 ?56) treatments was lower than low (188 ?46) or control treatments (184 ?104). Neither mean % viability nor % fertility was significantly different than control in any estrogen treatment. Although GSI was lower in females treated with the 2.5 mg/kg concentration of estrogen than in other treatments, the decrease was not significant. Average concentrations of vitellogenin (vtg) in control males from the three experiments ranged from 0.0 to 0.5 mg/ml plasma. In males from the highest concentration of EE2, average concentration of plasma vtg (480 mg/ml) was approximately forty times that in the high E2 treatment (12 mg/ml) and nine times that in the high E4 treatment (53 mg/ml). Overall, only EE2 significantly affected mean daily egg production of female cunner. All estrogens elevated plasma vtg in males, but EE2 notably more so than the others.