Reference
- Nash JP, Kime DE, Van der Ven LT, Wester PW, Brion F, Maack G, Stahlschmidt-Allner P, Tyler CR. Long-term exposure to environmental concentrations of the pharmaceutical ethynylestradiol causes reproductive failure in fish. Environ Health Perspect.112:1725-1733; 2004.

control F1 female

F1 female, 5 ng/L EE2
The oviducts of most F1 females in the 5 ng/L group contained massive accumulations of egg debris

This aberration suggests that these females were unable or at least inhibited to spawn, either physiologically or behaviourally.

adult female zebrafish, H&E (all images) accumulation of eggs in the ovary, F1 female, 0.5 ng/L EE2
On average, EE2 exposed F1 females (0.5 and 5 ng/L groups) had relatively high numbers of mature eggs in the ovary and in the oviduct, compared to group control and after discontinuation of exposure.
avg # mature oocytes in the ovary per section | |
control 5 ng/L, discontinued 5 ng/L 0.5 ng/L |
9.4 11.7 16.9 23.0 |
This suggests that ovulation in these females was inhibited.