Ocimum basilicum essential oil as an anesthetic for tambaqui Colossoma macropomum: Hematological, biochemical, non-specific immune parameters and energy metabolism

The present study evaluated the efficacy of Ocimum basilicum (basil) essential oil in the anesthetic induction and recovery of juvenile tambaqui Colossoma macropomum and verified its physiometabolic effects after biometric handling. Juveniles (86.51 ± 7.82 g) were exposed to different concentrations of basil essential oil: 400, 500, 600, 700, 800, 900, and 1000 μL L−1. Subsequently, the fish were divided into five groups: control (non-handled fish), handling without anesthetic (water only), handling with ethanol (720 μL L−1), and handling with Ocimum basilicum essential oil (400 and 800 μL L−1). The shortest (p