Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters

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. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 mu L L-1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 mu L L-1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul/Programa de Apoio a Nucleos de Excelencia (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior, Brazil (CAPES)info:eu-repo/semantics/publishedVersio

Humic acid and moderate hypoxia alter oxidative and physiological parameters in different tissues of silver catfish (Rhamdia quelen)

Aquatic animals are naturally exposed simultaneously to environments with different concentrations of humic acid (HA) and seasonal or daily variations of dissolved oxygen (DO) levels. This study investigated the effects of simultaneous exposure to different HA and DO levels on plasma ion levels and some hematological and oxidative parameters in different tissues of silver catfish (Rhamdia quelen). The fish were exposed to 0, 2.5 or 5 mg L(-1) HA for 120 h. After this period, each group was divided into two groups: normoxia and hypoxia. Exposure to the different DO levels lasted 96 h, totaling 216 h of experimentation. At the end of the experimental period, blood sampling was performed, and the fish were euthanized prior to the excision of the gills and the brain to evaluate hematological and oxidative parameters. To verify the antioxidant capacity of HA, total phenolic compounds were measured. In general, all tissues of silver catfish exposed simultaneously to hypoxia and different HA concentrations showed a reduction in lipid peroxidation levels, as well as a modulation of the antioxidant system. These effects occurred in an HA concentration-dependent manner. Thus, HA is beneficial to silver catfish exposed to hypoxia. These beneficial effects can be attributed, most likely, to the action of the different HA constituents and functional groups, including phenolic compounds, which have antioxidant properties.Fil: Riffel, Ana P. K.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Saccol, Etiane M. H.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Finamor, Isabela A.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Ourique, Giovana M.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Gressler, Luciane T.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Parodi, Thaylise V.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Goulart, Luis O. R.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Llesuy, Susana Francisca. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Baldisserotto, Bernardo. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; BrasilFil: Pavanato, María A.. Universidade Federal de Santa Maria. Departamento de Fisiologia e Farmacologia; Brasi

Pre-sedation and transport of Rhamdia quelen in water containing essential oil of Lippia alba: metabolic and physiological responses

The effects of transporting silver catfish (Rhamdia quelen) for 6 h in plastic bags containing 0 (control), 30 or 40 A mu L/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 A mu L/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. However, total ammonia nitrogen levels and net Na+, Cl- and K+ effluxes were significantly lower in the groups transported with EO of L. alba than those in the control group. PvO(2), PvCO(2) and HCO3 (-) were higher after transporting fish in 40 A mu L/L of EO of L. alba, but there were no significant differences between groups regarding blood pH or hematocrit. Cortisol levels were significantly higher in fish transported in 30 A mu L/L of EO of L. alba compared to those of the control group. The metabolic parameters (glycogen, lactate, total amino acid, total ammonia and total protein) showed different responses after adding EO to the transport water. In conclusion, while the EO of L. alba is recommended for fish transport in the conditions tested in the present study because it was effective in reducing waterborne total ammonia levels and net ion loss, the higher hepatic oxidative stress in this species with the same EO concentrations reported by a previous study led us to conclude that the 10-20 A mu L/L concentration range of EO and lack of pre-sedation before transport are more effective

Efficacy of eugenol and the methanolic extract of condalia buxifolia during the transport of the silver catfish rhamdia quelen

This study evaluated extracts of Condalia buxifolia as anesthetics for the silver catfish Rhamdia quelen. The effectiveness of eugenol and of the methanolic extract (ME) of C. buxifolia during the transport of this species was also assessed. Fish of two different weights (1.50±0.02 g and 165.70±22.50 g) were transferred to aquaria containing water with the C. buxifolia ME or with fractions obtained from the ME, such as the n-hexane, dichloromethane, ethyl acetate, n-butane and aqueous fractions, at concentrations from 0-300 μL L-1. The C. buxifolia ME in the 0.5-120 μL L-1 range caused only light sedation, and the fractions did not have an effect on the fish. In the second experiment, another group of fish was transported for 12 h in 15 plastic bags. The fish were divided into five groups: control, 1 or 2.5 μL L-1 eugenol and 25 or 50 μL L-1 C. buxifolia ME. The non-ionized ammonia levels were lower at the end of transport in the groups with the compounds than in that with water alone. Moreover, both compounds decreased the Na+, Cl-, and K+ net effluxes; therefore, their addition to the water during transport is advisable because they reduce fish mortality and ion loss.Este estudo investigou extratos de Condalia buxifolia como anestésico para jundiá Rhamdia quelen, e também a eficiência do eugenol e do extrato metanólico (EM) de C. buxifolia para utilização durante o transporte dessa espécie. Peixes de dois diferentes pesos (1,50±0,02 g e 165,70±22,50 g) foram transferidos para aquários contendo água com o EM de C. buxifolia ou frações obtidas a partir do EM (n-hexano, acetato de diclorometano, etil n- butano e aquoso, em concentrações na faixa de 0 - 300 μL L-1. O EM de C. buxifolia em concentrações na faixa de 0,5 - 120 μL L-1 causou somente uma sedação leve e as frações não tiveram efeito. No segundo experimento outro grupo de peixes foi transportado por 12 h em 15 sacos plásticos divididos em cinco tratamentos: controle, 1 ou 2,5 μL L-1 de eugenol e 25 ou 50 μL L-1 de EM de C. buxifolia. Os níveis de amônia nãoionizada foram menores nos tratamentos com ambos compostos em relação à água (controle). Além disso, ambos compostos diminuíram os efluxos líquidos de Na+, Cl- e K+ e, portanto, sua adição na água de transporte é aconselhável, pois reduzem a mortalidade e a perda de íons dos peixes