Endocrine disrupting effects of benzotriazole in rare minnow (Gobiocypris rarus) in a sex-dependent manner

•The endocrine disrupting effects of benzotriazole (BT) in rare minnow (Gobiocypris rarus) were analyzed.•Pathology, steroid hormone levels and the transcriptional profile of the HPG axis were affected by BT.•BT could adversely affect the rare minnows in a sex-dependent manner. Benzotriazole (BT), an anticorrosive agent, is widely used in industrial applications and household dishwashing agents. Despite its reported toxicity to aquatic organisms, little is known about its endocrine disrupting effects. In this study, adult Chinese rare minnows (Gobiocypris rarus) were exposed to 0.05, 0.5, and 5mgL−1 BT for 28d. The pathological damage in liver was associated with hypertrophy of the hepatocytes, nuclei pyknosis and vacuolization at 5mgL−1 groups. Additionally, the degeneration of the ovary and the stimulation of spermatogenesis were observed at 5mgL−1 groups. The plasma 17β-estradiol level was significantly increased in the males but decreased in the females at 5mgL−1 (p