Essential oils from Citrus x aurantium and Citrus x latifolia (Rutaceae) have anesthetic activity and are effective in reducing ion loss in silver catfish ( Rhamdia quelen )

Abstract

This study investigated the anesthetic effect of the essential oils (EOs) from the peel of Citrus x aurantium (EOCA) and Citrus x latifolia (EOCL) on silver catfish Rhamdia quelen. Fish were exposed to different concentrations of EOCA and EOCL to determine time of anesthesia induction and recovery. Induction of anesthesia was observed in all fish exposed to 400, 600 or 800 μL L−1 EOCA and 300, 400 or 500 μL L−1 EOCL. Another group of fish were exposed for 8 h to 50, 100, or 200 μL L−1 of either EOs. Overall, fish exposed to ethanol and both EOs presented higher ventilatory frequencies (VF) than the control group throughout the 8 h of exposure. Net ion (Na+, K+ and Cl−) effluxes and ammonia excretion were significantly lower in fish exposed to 50, 100 or 200 μL L−1 of either EOs compared to control fish. Mortality was 37% in fish exposed to 200 μL L−1 of either EOs after 8 h. These findings suggest that EOCA and EOCL are useful anesthetics and sedatives for Rhamdia quelen, but their usefulness as alternatives to reduce stress in fish transportation at the lower concentrations tested (50-100 µL L−1) deserves further study.

Dietary limonCitrus × latifoliafruit peel essential oil improves antioxidant capacity of tambaqui (Colossoma macropomum) juveniles

“…The predominance of limonene (49.7%) in EOCL observed in the present study is consistent with previous reports of Citrus EOs (Baba et al., 2016; Kummer et al, 2013; Lopes et al, 2018; Ngugi et al, 2016). The growth performance of tambaqui was not affected by dietary EOCL levels.…”

“…The EO of this plant (EOCL) is obtained mainly from fruit peels that are discarded as waste; therefore, it can be produced more economically than those of other plants (Baba et al., 2016). The EOCL presents antioxidant, antimicrobial, anaesthetic and sedative effects (Baba et al., 2016; Da Silva et al., 2013; Hamdan et al., 2010; Lopes et al, 2018). To the best of our knowledge, there are only two previous studies using C. lemon peel and both analysed the effects of its essential oil on growth and biochemical parameters.…”

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

“…Transport of silver catfish with the EO of Myrcia sylvatica (25 or 35 μL⋅L –1 ) reduced plasma cortisol and lactate levels, concomitantly with the decrease in the gene expression of crh and proopiomelanocortin b ( pomcb ), prolactin and somatolactin mRNAs compared to control fish without EO administration and subjected to the same procedure (Saccol et al, 2018b). 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.…”

Stress-reducing and anesthetic effects of the essential oils of Aloysia triphylla and Lippia alba on Serrasalmus eigenmanni (Characiformes: Serrasalmidae)

“…According to Ross (2008), the maximum acceptable time to induce deep anesthesia is 600 s. The present study showed that both EOs induced deep anesthesia in S. eigenmanni in less than 600 s; therefore, they can be used as anesthetics in this species. There are no studies of the anesthetic efficacy of geranial, limonene, and cis-carveol (Z-carveol) in fish, the main compounds of A. triphylla EO, but other EOs that anesthetize fish also contain these compounds in different amounts Lopes et al, 2018). The anesthetic efficacy of linalool and eucalyptol (syn 1,8-cineole), the main compounds of L. alba EO, was determined for R. quelen (Heldwein et al, 2014) and Oncorhynchus mykiss , respectively; the anesthetic efficacy of both compounds was also determined for Cyprinus carpio Khumpirapang et al, 2018).…”