Evaluation of the Sedative and Anesthetic Effects of Protium heptaphyllum Essential Oil in Juvenile Colossoma macropomum (Cuvier 1818): A Behavioral, Electrophysiological, and Plasma Glucose Study.

This study evaluated the sedative and anesthetic effects of Protium heptaphyllum essential oil (PHEO) in juvenile Colossoma macropomum through behavioral, electrophysiological, and biochemical analyses. Fish were exposed to different concentrations of PHEO (50, 75, 100, and 125 μL·L-1), and the parameters analyzed included latency to loss and recovery of postural reflex, cardiac activity (electrocardiogram), opercular movement, and plasma glucose levels. Chromatographic analysis revealed p-cymene, limonene, alpha-pinene and β-phellandrene as the major constituents of the oil. The results showed that PHEO induced sedation and anesthesia in a concentration-dependent manner, promoting bradycardia and a reduction in opercular movement frequency, with partial reversibility after exposure ceased. Plasma glucose increased significantly at higher concentrations. We conclude that PHEO has potential as a natural and safe anesthetic for aquaculture, especially at moderate concentrations.