Female zebrafish were exposed to semicarbazide for 96 hours or 28 days.
Semicarbazide exposure reduced plasma 17β-estradiol levels at 96 hour and 28 day.
Ovarian histology was affected after 28-day semicarbazide exposure.
Semicarbazide-exposed zebrafish showed altered reproductive gene transcription.
Semicarbazide exerted an anti-estrogenic effect in female zebrafish.