ABSTRACT:
The goal of this study was to investigate the sedative and anesthetic properties of essential oils (EOs) in map treefrog tadpoles (Hypsiboas geographicus) and to determine the sedation and deep anesthesia induction times as well as the recovery time. The tadpoles were exposed to one of the EOs from three plant species: Aniba rosaeodora (EOAR - 25, 50, 100 or 200µL L-1), Lippia origanoides (EOLO - 13, 25, 50, 100 or 200µL L-1), and Lippia alba (either chemotype citral [EOL-C - 25, 50, 100 or 200µL L-1] or linalool [EOL-L - 50, 75, 100 or 200µL L-1]) (n = 8 per replicate). The tadpoles exposed to 25 and 50µL L-1 EOL-C and EOL-L, respectively, were not anesthetized within 30min (the maximum time of observation), and those exposed to 200µL L-1 EOLO did not recover within 30min. Sedation, deep anesthesia and recovery times showed a concentration-dependent relationship for all EOs tested, with the exception of the recovery with EOLO. The results allowed concluding that all investigated EOs can be used to anesthetize tadpoles of H. geographicus, but the use of EOLO must not exceed 100µL L-1.
Key words:
amphibians; animal welfare; natural anesthetics