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.
View Article and Find Full Text PDFAmong all organotin compounds , triphenyltin hydroxide (TPhTH) is widely used as fungicide and moluscicide in Brazil. However, the effects of TPhTH on the biochemical parameters of non-target organisms, such as fish, are little known. The aim of the present study is to assess the possible toxic effects of different concentrations of waterborne TPhTH on silver catfish belonging to species Rhamdia quelen.
View Article and Find Full Text PDFThe effects of transporting silver catfish (Rhamdia quelen) for 6 h in plastic bags containing 0 (control), 30 or 40 µL/L of essential oil (EO) from Lippia alba leaves were investigated. Prior to transport, the fish in the two experimental groups were sedated with 200 µL/L of EO for 3 min. After transport, dissolved oxygen, carbon dioxide, alkalinity, water hardness, pH, temperature and un-ionized ammonia levels in the transport water did not differ significantly among the groups.
View Article and Find Full Text PDFThe anesthetic activities of the essential oils (EOs) of Hesperozygis ringens (EOHR) and Lippia alba (EOLA) and their effects in silver catfish (Rhamdia quelen) after anesthesia and recovery were investigated. Fish (32.19 ± 1.
View Article and Find Full Text PDFThis study investigated the efficacy of the essential oil (EO) of Aloysia triphylla as an anesthetic for albino and gray strains of silver catfish, Rhamdia quelen. Juveniles were exposed to concentrations between 20 and 800 μL L(-1) EO of A. triphylla to evaluate time of induction and recovery from anesthesia.
View Article and Find Full Text PDFTriphenyltin (TPhT) is used worldwide in pesticide formulas for agriculture. Toxic effects of this compound to aquatic life have been reported; however, the biochemical response of fish exposed to different concentrations of TPhT hydroxide (TPhTH) was investigated for the first time in this study. The lethal concentration (LC50) of TPhTH to silver catfish, Rhamdia quelen, was calculated from an acute-exposure experiment (96 h).
View Article and Find Full Text PDFBackground: Lippia alba is effective in sedating and reducing stress to fish during transportation. Because some in vitro studies have demonstrated the antioxidant activity of L. alba, we hypothesized that its use in vivo could result in antioxidant effects post mortem.
View Article and Find Full Text PDFThis study investigated the relationship between ion levels (Na⁺, Cl⁻, K⁺, Ca²⁺, and Mg²⁺) in the fluid phase and total chyme of the contents of the gastrointestinal tract segments of freshwater and marine-estuarine teleosts collected in different salinities (0-34 ppt) in estuarine and freshwater portions of the São Gonçalo channel, southern Brazil. In addition, the relative contribution of feeding and osmoregulation to the ionic content of each portion of the gastrointestinal tract of fishes collected in different ambient salinities was analyzed. There was no relationship between salinity and ion levels in the fluid phase and total chyme of the segments of the gastrointestinal tract when considering all species together.
View Article and Find Full Text PDFThis study investigated the effectiveness of eugenol and of the essential oil (EO) of Lippia alba when used in the transport of the silver catfish (Rhamdia quelen). These investigations involved measurements of blood (pH, PvO(2), PvCO(2) and HCO(3) (-)) and water parameters, survival and ionoregulatory balance. Fish (301.
View Article and Find Full Text PDFAluminum (Al) is one of the most abundant elements of the planet and exposure to this metal can cause oxidative stress and lead to various signs of toxicity in plants. Plants are essential organisms for the environment as well as food for humans and animals. The toxic effect of aluminum is the major cause of decreased crop productivity.
View Article and Find Full Text PDFWe investigated how pesticide contamination of water affects the metabolism of the silver catfish, Rhamdia quelen, by studying fish maintained at two sites with low and high anthropic activity (Lino Creek, southern Brazil). Several pesticides were found at both stream sites. After 30 days plasma glucose levels were higher in fish exposed to water in the low anthropic activity site than those exposed to water in the high anthropic activity site.
View Article and Find Full Text PDFThe objective of this study was to evaluate the effect of thorium (Th) bioaccumulation on the metabolism of silver catfish (Rhamdia quelen) through biochemical parameters of the muscle (glycogen, glucose, lactate, protein, and ammonia). In addition, lipidic peroxidation levels (TBARS), catalase (CAT) and glutathione-S-transferase (GST) in the gills and in hepatic and muscular tissues were also analyzed. Cytogenetic parameters were studied through the evaluation of nuclear abnormalities in red blood cells.
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