Effects of clove oil, essential oil of Lippia alba and 2-phe anaesthesia on juvenile meagre, Argyrosomus regius (Asso, 1801)

Abstract

The objectives of this experiment were to (i) determine the efficacy of essential oils of clove (CO) and Lippia alba (EOLA) to induce deep anaesthesia in juvenile specimens (49.0 AE 6.2 g body mass, 16.6 AE 0.8 cm; n = 8 per treatment) of meagre (Argyrosomus regius); and (ii) study the feasibility of these substances, together with 2-phenoxyethanol (2-PHE), as potential sedatives [low concentration: (i) EOLA: 12 mg L À1 ; (ii) CO: 1 mg L À1 ; and (iii) 2-PHE: 33 mgÁL À1 ; n = 8 per treatment] for live fish transport of this species. All test were performed at a constant temperature (18°C). Thus, the main primary stress indicator (plasma cortisol) and secondary factors (plasma metabolites) were evaluated. In addition, growth hormone (GH) mRNA expression was also evaluated in the pituitary gland. The results indicated that EOLA is considered to be effective for deep anaesthesia when the concentration is close to 160 mg L À1 , while CO produces the same effect when lower concentrations are added (40-50 mg L À1 ). Regarding sedative concentrations, a significant~3-fold increase in plasma cortisol levels was detected in the EOLA group when compared to control specimens. In addition, glucose levels were not reduced and significantly increased (~1.6-fold) for 2-PHE in relation to the control fish. None of the anaesthetics promoted a significant difference for GH expression with respect to the control group, but a significant~2-fold increase for 2-PHE treatment with respect to the EOLA exposition was found in this gene expression. Results show that none of the anaesthetics analysed, at least in the ranges of concentrations used in this study (EOLA 12 mg L À1 , CO 1 mg L À1 , 2-PHE 33 mg L À1 ), are recommended for live fish transport, as shown by the absence of inhibition on the stress parameters assessed.

Application of herbal anaesthetics in aquaculture

“…The essential oil at the concentrations of 54–160 mg L −1 induced deep anaesthesia in meagre within 300–100 s, with recovery time of about 200 s (Cárdenas et al . ).…”

“…Application of 12 mg L −1 essential oil during 4‐h simulated transportation led to a significant increase in cortisol response, slight (nonsignificant) increase in glucose and lactate response, and decrease in growth hormone gene expression (Cárdenas et al . ).…”

Narrowing the Range of Environmental Salinities Where Juvenile Meagre (Argyrosomus regius) Can Be Cultured Based on an Osmoregulatory Pilot Study

“…The meagre (Argyrosomus regius) arose as a promising species for aquaculture diversification in several Mediterranean countries [24]. There are many studies focused on different aspects of the culture of this species such as dietary requirements [25][26][27], stocking density [28], handling procedures [29], and even fillet quality [30]. However, as this is a euryhaline species which naturally spends the first two years of life in estuarine-brackish waters [31,32], and is cultured in salt-marshes with great fluctuations on the environmental salinity throughout the year [33], it should also be relevant to study how environmental salinity affects the osmoregulatory and energy management processes of this species.…”

Lippia alba(Verbenaceae) hydrolate as sedative of tambaqui (Colossoma macropomum) juveniles in simulated transport conditions

“…Examples include the chemotypes citral, limonene and linalool‐citral (Blank et al., ; Silva, Oliveira, Costa, Bizzo & Oliveira, ). Several studies have confirmed the essential oil of L. alba as viable anaesthetic alternative in aquaculture (Cárdenas et al., ; Cunha et al., ; Hohlenwerger et al., ; Souza et al., in press; Toni et al., ), and as sedative and stress reducers in fish and crustacean transport (Azambuja et al., ; Becker et al., ; Hohlenwerger et al., ; Parodi et al., ).…”