Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters

Abstract

This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 µL L −1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na + and K + levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 µL L −1 . However, most evaluated blood parameters showed compensatory responses due to EO exposure.

Application of herbal anaesthetics in aquaculture

“…This plant essential oil is rich in carvone (58.7%) and limonene (33.7%) (Fogliarini et al . ). In dusky grouper ( Epinephelus marginatus ), 50 and 75 μL L −1 essential oil is sedative (429 and 286 s); however, at the concentrations of 100–400 μL L −1 , the essential oil induces anaesthesia within 1555–90 s, with recovery time of 330–565 s (Fogliarini et al .…”

“…In dusky grouper ( Epinephelus marginatus ), 50 and 75 μL L −1 essential oil is sedative (429 and 286 s); however, at the concentrations of 100–400 μL L −1 , the essential oil induces anaesthesia within 1555–90 s, with recovery time of 330–565 s (Fogliarini et al . ). Short‐term exposure to 50–300 μL L −1 of the essential oil leads to increase in blood Pv O 2 and Pv CO 2 and glucose, and decrease in haematocrit and haemoglobin (Fogliarini et al .…”

“…Short‐term exposure to 50–300 μL L −1 of the essential oil leads to increase in blood Pv O 2 and Pv CO 2 and glucose, and decrease in haematocrit and haemoglobin (Fogliarini et al . ).…”

Essential Oils as Stress-Reducing Agents for Fish Aquaculture: A Review

“…In the marine dusky grouper the use of 50 and 300 μL⋅L –1 of the EO of Aloysia polystachya for, respectively, sedation and anesthesia, did not affect plasma glucose, Na + , and Cl – levels compared to control fish (handled as the anesthetized fish) (Fogliarini et al, 2017; Figure 2).…”

“…The use of EOs as sedatives or anesthetics to minimize possible damage to fish resulting from handling was recently demonstrated in several species (Cunha et al, 2010; Benovit et al, 2012; Tondolo et al, 2013; Toni et al, 2015; Hashimoto et al, 2016; Pedrazzani and Ostrenski Neto, 2016; Ribeiro et al, 2016; Barbas et al, 2017a, b; Fogliarini et al, 2017; Bodur et al, 2018a, b; Hoseini et al, 2018; Souza et al, 2018a, b). For minor procedures such as biometry and collection of blood samples, lower concentrations of EOs can be used that induce tranquilization and light sedation, in order to minimize stress and reduce plasma cortisol levels (Table 1).…”