Ventilatory frequency and anesthetic efficacy in silver catfish, Rhamdia quelen: a comparative approach between different essential oils

Abstract

This study investigated the efficacy of essential oils of Lippia alba (EOLA) citral chemotype and Lippia origanoides (EOLO) and their effects on ventilatory frequency (VF) of silver catfish, Rhamdia quelen. Fish were exposed to 50-300 µL L −1 of EOLA and 25-300 µL L −1 of EOLO to determine induction times to sedation, anesthesia, and recovery. Moreover, VF was determined in fish exposed to 5 or 10 µL L −1 of EOLA and of EOLO for 8 h. The increasing concentration of essential oils proportionally decreased sedation and anesthesia induction times. The highest EOLA concentration increased VF of fish from the control group at 1 h of exposure, but VF decreased at both EOLO concentrations after 2 h. The EOLA citral chemotype and EOLO were effective sedatives and anesthetics for silver catfish. However, EOLO was the most suitable sedative for additional studies regarding fish transport as it reduced VF and did not induce VF increase in silver catfish. The EOLA citral chemotype and EOLO are effective sedatives and anesthetics for silver catfish. Moreover, the EOLO is recommended for transport of silver catfish, because it maintains the ventilatory frequency constant, avoiding a possible metabolic stress.

Minimally invasive evaluation of the anaesthetic efficacy of MS‐222 for ornamental discus fish using skin mucus biomarkers

“…Ventilation rate is regarded as a sympathetic response, which quickly increases in response to stressors (Priede, 1985). In this study, as expected, respiratory frequency showed an earlier increase and decrease trend during anaesthesia, and this could be as a result of the fact that the anaesthetic may produce a transitory stress which increases respiratory frequency (Becker et al, 2018), indicating the slight anaesthesia of fish at stages A1 and A2, and the deep anaesthesia at stage A3. Similar results were observed in the previous studies (Li et al, 2018; Zhang et al, 2015), whereas a time lag in the decrease of respiratory frequency was observed for S. aequifasciata compared with the studies on koi carp Cyprinus carpio (Zhang et al, 2015) and largehead hairtail juvenile Trichiurus haumela (Li et al, 2018) which showed a decrease trend from stage A2.…”

Essential oil of Ocimum basilicum and Eugenol as Sedatives for Nile Tilapia

“…For R. quelen, ethanol increased the ventilatory frequency during the first four hours of exposure, when compared to the essential oil of Citrus aurantium and Citrus latifolia (Lopes et al, 2018). It was also observed for R. quelen that fish from the ethanol group showed lower ventilatory rate than the control group at 4 h of exposure (Cunha et al, 2017) and the fish exposed to the ethanol progressively reduced the ventilatory frequency up to 4 h (Becker et al, 2018). These changes did not occur in the present study with Nile tilapia, so we can infer that the ventilatory responses of fish to ethanol are quite variable.…”

“…In tambaqui C. macropomum sedated with essential oils of L. alba (chemotype citral and linalool) and L. origanoides (chemotype carvacrol) it was not possible to establish a direct relationship between the increase in anesthetic concentration and reduction in ventilatory frequency (Silva et al, 2019). In R. quelen exposed to the essential oils of L. alba (chemotype citral) and L. origanoides no major differences in the ventilatory frequency were observed in relation to the control group (Becker et al, 2018). However, the essential oils of Hesperozygis ringens and L. alba (chemotype linalol) reduced the ventilatory frequency in R. quelen sedated at concentrations of 300 or 450 μL L -1 (Toni et al, 2014).…”

“…The assessment of ventilatory frequency is important to understand the physiological response of fish to anesthetics (Becker et al, 2012(Becker et al, , 2018. Several studies have been carried…”

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

“…Exposure of silver catfish to the EOs of Citrus × aurantium , Citrus × latifolia (50–100 μL⋅L –1 ), increased ventilatory frequency, but reduced ion loss and ammonia excretion compared to control fish subjected to the same procedure (Lopes et al, 2018). The EOs of Cunila galioides (25 and 50 μL⋅L –1 ) and Origanum majorana (100 μL⋅L –1 ) also decreased ion loss (Cunha et al, 2017) and Lippia origanoides (5–10 μL⋅L –1 ) reduced ventilatory frequency in silver catfish after 6 and/or 8 h of exposure (Becker et al, 2018) both compared to their respective control fish subjected to the same procedure. For instance, these EOs apparently reduced stress and may also be useful for fish transport (Figure 2).…”