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This study evaluated the use of essential oil of Ocimum gratissimum (EOOG) for anesthesia and in transport of Colossoma macropomum. Experiment 1, Test 1, anesthesia induction and recovery times were determined using different EOOG concentrations (0, 20, 50, 100, 200, 300 mg L− 1), with two size classes: Juveniles I (0.86 g) and Juveniles II (11.46 g) (independent tests in a completely randomized design). Based on the results of Test 1, in Test 2 Juveniles II were exposed to EOOG concentrations: 0, 20, 100 mg L− 1. Tissue samples were collected immediately after induction and 1 h post-recovery, to assess oxidative status variables. Experiment 2, Juveniles I (0.91 g) and Juveniles II (14.76 g) were submitted to transport in water with different concentrations of EOOG (0, 5, 10 mg L− 1) (independent tests in a completely randomized design). The effects on oxidative status variables were evaluated. Concentrations between 50 and 200 mg L− 1 EOOG can be indicated for Juveniles I, while concentrations between 50 and 100 mg L− 1 EOOG for Juveniles II. The concentration of 100 mg L− 1 EOOG was able to prevent oxidative damage in the liver. In Experiment 2, the concentrations of 5 and 10 mg L− 1 EOOG added to the transport water caused sedation for both studied size classes of juveniles and did not cause oscillations in water quality variables nor any mortality. The concentration of 10 mg L− 1 EOOG improved the oxidative status. It can be concluded that EOOG can be used for anesthesia and transport of C. macropomum.

The objective of this work was to evaluate the use of Myrcia sylvatica Hydrolate (MSH) as a sedative under conditions of simulated transport of Colossoma macropomum juveniles. Simulated a 17 h tran...

The study aimed to establish the lethal concentration at 96 h (LC50-96h) of hydrolate of Lippia alba (citral chemotype) (LAH) in juvenile tambaqui ( Colossoma macropomum ), as well as to identify the anaesthetic induction and recovery times. The acute toxicity test LC50-96h was performed in five animals per replicate (three replicates per treatment). The concentrations tested were 5, 6, 7 and 8% hydrolate diluted in water, and a control treatment containing only water. During the LC50-96h test, the physical and chemical parameters of the water were evaluated (temperature, dissolved oxygen, pH, and electrical conductivity). Water was also collected at the beginning and end of the experiment for the analysis of alkalinity, hardness, total ammonia, Na+, K+ and Cl− levels. Gills were collected from the survival fish to determine the density of gill mucous cells (DGMC). The concentrations of 10, 15, 20 and 25% of the hydrolate diluted in water were used for anaesthesia tests, which lasted up to 30 min (15 animals/treatment). After anaesthesia, the recovery time was evaluated. The toxicity test indicated LC50-96h 7.43% (confidence interval: 6.9–8.2%). During LC50-96h, ion loss and increased mucous gill cell density was observed in treatments with LAH. However, a long exposure time (up to 96 h) at lower concentrations (6, 7 and 8%) of the by-product caused osmoregulatory (ion loss) and cellular (increased DGMC) disturbances. The data also indicated that increasing the concentration of hydrolate proportionally decreases the time for anaesthesia induction. Anaesthesia recovery time was not significantly affected by LAH concentration. The concentrations of 20 and 25% of LAH showed the best times for anaesthesia induction in juvenile tambaqui (1.76 min and 2.01 min, respectively).

portuguesO objetivo deste estudo foi avaliar a eficacia do oleo essencial de Lippia alba quimiotipo citral (EOLA) como aditivo em transporte simulado com diferentes densidades de carga de juvenis de tambaqui (Colossoma macropomum). O transporte simulado de juvenis de tambaqui em tres densidades de carga (30, 60 e 90 peixes / L) foi realizado apenas com agua (WC) ou 20 μL.L-1 EOLA. Niveis de oxigenio dissolvido, pH, condutividade e temperatura da agua foram medidos no inicio e no final do transporte simulado. O tratamento com EOLA nao alterou a sobrevivencia ou os niveis de oxigenio dissolvido no final da simulacao. O pH da agua no final da simulacao com o EOLA foi menor que o do WC, mas nao mudou com a densidade de carga. A condutividade da agua aumentou com a densidade de carga, no entanto foi menor nos grupos com EOLA. A adicao de EOLA pode ser util no transporte de longo prazo em altas densidades de carga, mas sao necessarios mais estudos relacionados a fisiologia do tambaqui EnglishThe objective of this study was to evaluate the efficacy of the citral chemotype of Lippia alba essential oil (EOLA) as an additive in a simulated transport with different loading densities of tambaqui (Colossoma macropomum) juveniles. Simulated transport of tambaqui juveniles at three loading densities (30, 60 and 90 fish/L) was carried out either with only water (WC) or 20 μL.L-1 EOLA. Dissolved oxygen levels, pH, conductivity and temperature of the water were measured at the beginning and end of the simulated transport. Treatment with EOLA did not change survival or dissolved oxygen levels at the end of simulation. The pH of the water at the end of simulation with EOLA was lower than in that of WC but did not change with loading density. Water conductivity increased with loading density; however, it was lower in the groups with EOLA. The addition of EOLA can be useful in long-term transportation at high loading densities, but further studies related to tambaqui physiology are required

The phytochemical linalool has synergistic activity with florfenicol against Aeromonas hydrophila in an in vitro study. However, there is a lack of in vivo studies to confirm this finding. Therefore, the aim of this study was to evaluate the in vivo effect of the combination of florfenicol with linalool via bath against aeromonosis in silver catfish (Rhamdia quelen) and their responses in redox balance and histology of gills, liver, and caudal kidney. In a previous test, a survival curve of silver catfish infected with A. hydrophila and treated with different concentrations of florfenicol via bath was performed. Florfenicol via bath at low concentration (12 mg/L) was able to increase the survival of infected fish. In the main test, the combined effect of florfenicol with linalool was evaluated. Bath with both substances decreased thiobarbituric acid reactive substances - TBARS levels and prevented histological alterations in gills and liver of infected fish. However, the use of these substances via bath was not able to modify the changes observed in other parameters related to the redox balance of infected fish. There was still a satisfactory concentration of linalool 1 d after the bath. In general, the use of florfenicol with linalool would be an appropriate combination for treatment of fish aeromonosis.

Lippia alba hydrolate (LAH) is produced as a secondary product in essential oil extraction. The objective of this study was to evaluate the use of LAH in a simulation of the transport of tambaqui (Colossoma macropomum) juveniles. A series of 17 hr simulations were performed using load densities of 30, 60 and 90 juveniles per L and four LAH concentrations of 0.4%, 1%, 2% and 5%, with a control of just water. Fish survival, temperature, dissolved oxygen, conductivity, pH, ammonia excretion, alkalinity water hardness and net Na+, K+, Cl- fluxes, were all evaluated before and after the transport simulations. Mucous cell densities in the gills were also determined microscopically, post simulation. The results showed that addition of 5% LAH achieved better survival during the simulation than the water control. Dissolved oxygen was significantly lower with an increased load density. Also, conductivity, NH4 excretion and net ionic fluxes (K+ and Cl−) were lower with 5% LAH, although mainly where higher load densities were tested. Mucous cell density was lower in LAH concentrations of 2% and 5%, again with higher load densities. In view of these findings, it is suggested that 5% LAH is an effective sedative for use in the transport of tambaqui, mainly with high load densities. This work is the first study of LAH and highlights its potential applications in aquaculture management.

The aim of this study was to investigate the anesthetic effect of the essential oils (EOs) of Lippia alba (citral and linalool chemotypes, EOLA-C and EOLA-L respectively) and Lippia origanoides (chemotype carvacrol, EOLO-Ca) on tambaqui (Colossoma macropomum) juveniles. The tested concentrations of the L. alba and L. origanoides EOs were: 25, 50, 100, and 200 μL/L. Time required to reach the stages of sedation, deep anesthesia, and recovery, as well as ventilatory frequency, were monitored for each EO concentration. The results indicated that all EO concentrations tested induced tambaqui anesthesia and that the ventilatory frequency was altered by the EOs. L. origanoides showed the shortest time to induce sedation and anesthesia, but had long recovery times. L. alba EO (citral 100 μL/L and linalool 200 μL/L) can be used to efficiently anaesthetise tambaqui juveniles with an efficient recovery. RESUMO: O objetivo deste estudo foi investigar o efeito anestésico dos óleos essenciais (EOs) de Lippia alba (quimiotipos citral e linalool - EOLA-C e EOLA-L respectivamente) e Lippia origanoides (quimiotipo carvacrol- EOLO-Ca) em juvenis de tambaqui (Colossoma macropomum). As concentrações testadas dos EOs de L. alba e L. origanoides foram: 25, 50, 100 ou 200 μL/L. O tempo para atingir os estágios de sedação, anestesia profunda, recuperação e frequência ventilatória foram monitorados em cada concentração de EO. Os resultados indicam que todas as concentrações testadas dos OE induziram a anestesia do tambaqui e que a frequência ventilatória foi alterada pelos EOs. L. origanoides mostrou o tempo mais rápido para induzir sedação e anestesia, mas os tempos de recuperação foram longos. EO L. alba (citral 100 μL/L e linalol 200 μL/L) pode ser utilizado como anestésico em juvenis de tambaqui, pela eficiência em anestesiar e recuperar.

This study aimed to evaluate the sedative and anesthetic potential of the essential oil (PHEO) and hydrolate (PHH) from the fruit of Protium heptaphyllum and the isolated compounds (IC) of PHEO in tambaqui (Colossoma macropomum) juveniles. Fish were placed in aquaria with different concentrations of PHEO, PHH or IC (sabinene, terpinen-04-ol, γ-terpinene and α-pinene) to evaluate sedative and anesthetic efficacy. In another experiment, fish were transported for 22 h with 10% anesthetic concentrations added to the water of transport. No similarities regarding the major compounds of PHEO and PHH were observed. No mortality was observed during the experiments, and PHH did not show any sedative or anesthetic effect. PHEO induced sedation at 250 mg L−1 and deep anesthesia at 500, 750 and 1000 mg L−1. The recovery time increased with increasing concentration of PHEO. There was a significant difference in the time to induce deep anesthesia between PHEO and IC. Water conductivity and mucous cell density were lower in the transport with 50 mg L−1 PHEO. Tambaqui transported with 50 mg L−1 PHEO and 11.6, 17.4, and 23.2 mg L−1 terpinen-04-ol presented lower net whole body K+ and Cl− effluxes. PHEO is an alternative as sedative and anesthetic for tambaqui juveniles, and the concentration of 500 mg L−1 was the best for deep anesthesia. The use of 50 mg L−1 PHEO was effective for the transport of this species because it reduced net K+ and Cl− effluxes and did not stimulate proliferation mucous cells.

The trend toward using plant-based ingredients in aquafeeds has raised important concerns for aquaculture owing to the negative impacts of mycotoxins on fish health; with emphasis for contamination by fumonisin B1 (FB1). The brain is an important target of FB1; however, study of the pathways linked to brain damage is limited to an analysis of histopathological alterations. Reports have demonstrated the protective effects of dietary supplementation with diphenyl diselenide (Ph2Se2) in the brains of fish subjected to several environmental insults; nevertheless, its neuroprotective effects in fish fed with diets contaminated with FB1 remain unknown. Therefore, the aim of this study was to evaluate whether oxidative damage may be a pathway associated with FB1-induced neurotoxicity, as well as to evaluate whether dietary supplementation with Ph2Se2 prevents or reduces FB1-mediated brain oxidative damage in silver catfish. Brain reactive oxygen species (ROS), lipid peroxidation (LOOH) and protein carbonylation increased on day 30 post-feeding in animals that received FB1-contaminated diets compared to the control group, while brain antioxidant capacity against peroxyl radicals (ACAP) levels and catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities were lower. Diphenyl diselenide dietary supplementation avoid increases in brain ROS levels, as well minimizing the augmentation of LOOH levels. Furthermore, Ph2Se2 prevented impairment of brain ACAP levels, as well as GPx and GST activities elicited by FB1-contaminated diets. These data suggest that dietary supplementation with 3 mg/kg Ph2Se2 prevented FB1-induced brain damage in silver catfish, and this protective effect occurred through avoided of excessive ROS production, as well as via prevention of brain lipid damage. Furthermore, Ph2Se2 exerted its neuroprotective effects via ameliorative effects on the enzymatic and non-enzymatic antioxidant defense systems, and may be an approach to prevent FB1-induced brain oxidative stress; however, is not an alternative to prevent the impairment on performance caused by FB1.

The aim of this study was to determine whether purinergic signaling is a pathway associated with fumonisin B1 (FB1)-induced impairment of immune and hemostatic responses. We also determined whether dietary supplementation with diphenyl diselenide (Ph2Se2) prevents or reduces these effects. Splenic nucleoside triphosphate diphosphohydrolase (NTPDase) activity for adenosine triphosphate (ATP) and adenosine diphosphate (ADP) as substrates and total blood thrombocytes counts were significant lower in silver catfish fed with FB1-contaminated diets than in fish fed with a basal diet, while splenic adenosine deaminase (ADA) activity and metabolites of nitric oxide (NOx) levels were significant higher. Also, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were significant lower in silver catfish fed with FB1-contaminated diets than in fish fed with a basal diet. Dietary supplementation with 3 mg Ph2Se2/kg of feed effectively modulated splenic NTPDase (ATP as substrate), ADA, GPx and SOD activities, as well as NOx levels, and was partially effective in the modulation of spleen NTPDase activity (ADP as substrate) and total blood thrombocytes count. These data suggest that splenic purinergic signaling of silver catfish fed with FB1-contaminated diets generates a pro-inflammatory profile that contributes to impairment of immune and inflammatory responses, via reduction of splenic ATP hydrolysis followed possible ATP accumulation in the extracellular environment. Reduction of ADP hydrolysis associated with possible accumulation in the extracellular environment can be a pathophysiological response that restricts the hemorrhagic process elicited by FB1 intoxication. Supplementation with Ph2Se2 effectively modulated splenic enzymes associated with control of extracellular nucleotides (except ADP; that was partially modulated) and nucleosides, thereby limiting inflammatory and hemorrhagic processes.