Impact evaluation caused by disponibility of free and complexed 17β-estradiol into cyclodextrin in the aquatic environment in tilapia (Oreochromis niloticus)

ABSTRACT Toxic effects of free and complexed 17β-estradiol (E2) hormone into β-cyclodextrin (CD) on the behavior and physiology of tilapia (Oreochromis niloticus) were evaluated. The fish were observed for 30 days in two stages of development (fingerling and juvenile) by the ad libitum method to make an ethogram. After this, juveniles were divided into three groups: control and exposed to free E2 (10ng/L) and complexed into β-cyclodextrin (β-CD:E2) for 90 days. The behavior was evaluated through scan sampling method, feed intake, body mass and mortality at different intervals. The fingerlings and juveniles showed behavioral patterns with different display frequencies (P